Exemplo n.º 1
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    def save_ebc(self, filename, force=True, default=0.0):
        """
        Save essential boundary conditions as state variables.
        """
        output("saving ebc...")
        variables = self.get_variables(auto_create=True)

        ebcs = Conditions.from_conf(self.conf.ebcs, self.domain.regions)
        epbcs = Conditions.from_conf(self.conf.epbcs, self.domain.regions)

        try:
            variables.equation_mapping(ebcs, epbcs, self.ts, self.functions, problem=self)
        except:
            output("cannot make equation mapping!")
            raise

        state = State(variables)
        state.fill(default)

        if force:
            vals = dict_from_keys_init(variables.state)
            for ii, key in enumerate(vals.iterkeys()):
                vals[key] = ii + 1

            state.apply_ebc(force_values=vals)

        else:
            state.apply_ebc()

        out = state.create_output_dict(extend=True)
        self.save_state(filename, out=out, fill_value=default)
        output("...done")
Exemplo n.º 2
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    def __call__(self, problem=None, data=None):
        from sfepy.base.base import select_by_names
        from sfepy.discrete.variables import Variables
        from sfepy.discrete.state import State
        from sfepy.discrete.conditions import Conditions

        problem = get_default(problem, self.problem)

        conf_ebc = select_by_names(problem.conf.ebcs, self.ebcs)
        conf_epbc = select_by_names(problem.conf.epbcs, self.epbcs)
        ebcs = Conditions.from_conf(conf_ebc, problem.domain.regions)
        epbcs = Conditions.from_conf(conf_epbc, problem.domain.regions)

        conf_variables = select_by_names(problem.conf.variables, self.variable)
        problem.set_variables(conf_variables)
        variables = Variables.from_conf(conf_variables, problem.fields)
        variables.equation_mapping(ebcs, epbcs, problem.ts, problem.functions)
        state = State(variables)
        state.fill(0.0)
        state.apply_ebc()

        corr_sol = CorrSolution(name=self.name,
                                state=state.get_parts())

        self.save(corr_sol, problem, variables)

        return corr_sol
Exemplo n.º 3
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    def test_epbcs(self):
        from sfepy.discrete import Function, Functions
        from sfepy.discrete.conditions import Conditions, PeriodicBC
        from sfepy.discrete.common.dof_info import expand_nodes_to_equations
        from sfepy.discrete.fem.periodic import match_y_line

        variables = self.variables
        regions = self.problem.domain.regions

        match_y_line = Function('match_y_line', match_y_line)
        pbc = PeriodicBC('pbc', [regions['LeftStrip'], regions['RightStrip']],
                         {'u.[1,0]' : 'u.[0,1]'}, match='match_y_line')

        functions = Functions([match_y_line])

        epbcs = Conditions([pbc])
        variables.equation_mapping(ebcs=None, epbcs=epbcs,
                                   ts=None, functions=functions)

        vec = init_vec(variables)
        variables.apply_ebc(vec)

        var = variables['u']
        var_bcs = epbcs.group_by_variables()['u']
        bc = var_bcs['pbc']
        bc.canonize_dof_names(var.dofs)

        nods0 = var.field.get_dofs_in_region(bc.regions[0])
        nods1 = var.field.get_dofs_in_region(bc.regions[1])

        coors0 = var.field.get_coor(nods0)
        coors1 = var.field.get_coor(nods1)
        i0, i1 = match_y_line(coors0, coors1)

        eq0 = expand_nodes_to_equations(nods0[i0], bc.dofs[0], var.dofs)
        eq1 = expand_nodes_to_equations(nods1[i1], bc.dofs[1], var.dofs)

        ok = True

        _ok = len(nm.setdiff1d(eq0, var.eq_map.master)) == 0
        if not _ok:
            self.report('master equations mismatch! (set(%s) == set(%s))'
                        % (eq0, var.eq_map.master))
        ok = ok and _ok

        _ok = len(nm.setdiff1d(eq1, var.eq_map.slave)) == 0
        if not _ok:
            self.report('slave equations mismatch! (set(%s) == set(%s))'
                        % (eq1, var.eq_map.slave))
        ok = ok and _ok

        off = variables.di.indx['u'].start
        _ok = nm.allclose(vec[off + eq0], vec[off + eq1], atol=1e-14, rtol=0.0)
        if not _ok:
            self.report('periodicity test failed! (%s == %s)'
                        % (vec[off + eq0], vec[off + eq0]))
        ok = ok and _ok

        return ok
Exemplo n.º 4
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    def save_ebc(self, filename, ebcs=None, epbcs=None,
                 force=True, default=0.0):
        """
        Save essential boundary conditions as state variables.

        Parameters
        ----------
        filename : str
            The output file name.
        ebcs : Conditions instance, optional
            The essential (Dirichlet) boundary conditions. If not given,
            `self.conf.ebcs` are used.
        epbcs : Conditions instance, optional
            The periodic boundary conditions. If not given, `self.conf.epbcs`
            are used.
        force : bool
            If True, sequential nonzero values are forced to individual `ebcs`
            so that the conditions are visible even when zero.
        default : float
            The default constant value of state vector.
        """
        output('saving ebc...')
        variables = self.get_variables(auto_create=True)

        if ebcs is None:
            ebcs = Conditions.from_conf(self.conf.ebcs, self.domain.regions)

        if epbcs is None:
            epbcs = Conditions.from_conf(self.conf.epbcs, self.domain.regions)

        try:
            variables.equation_mapping(ebcs, epbcs, self.ts, self.functions,
                                       problem=self)
        except:
            output('cannot make equation mapping!')
            raise

        state = State(variables)
        state.fill(default)

        if force:
            vals = dict_from_keys_init(variables.state)
            for ii, key in enumerate(vals.iterkeys()):
                vals[key] = ii + 1

            state.apply_ebc(force_values=vals)

        else:
            state.apply_ebc()

        out = state.create_output_dict(extend=True)
        self.save_state(filename, out=out, fill_value=default)
        output('...done')
Exemplo n.º 5
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    def setup_ic(self, conf_ics=None, functions=None):
        conf_ics = get_default(conf_ics, self.conf.ics)
        ics = Conditions.from_conf(conf_ics, self.domain.regions)

        functions = get_default(functions, self.functions)

        self.equations.setup_initial_conditions(ics, functions)
Exemplo n.º 6
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    def set_ics(self, ics=None):
        """
        Set the initial conditions to use.
        """
        if isinstance(ics, Conditions):
            self.ics = ics

        else:
            conf_ics = get_default(ics, self.conf.ics)
            self.ics = Conditions.from_conf(conf_ics, self.domain.regions)
Exemplo n.º 7
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    def set_bcs(self, ebcs=None, epbcs=None, lcbcs=None):
        """
        Update boundary conditions.
        """
        if isinstance(ebcs, Conditions):
            self.ebcs = ebcs

        else:
            conf_ebc = get_default(ebcs, self.conf.ebcs)
            self.ebcs = Conditions.from_conf(conf_ebc, self.domain.regions)

        if isinstance(epbcs, Conditions):
            self.epbcs = epbcs

        else:
            conf_epbc = get_default(epbcs, self.conf.epbcs)
            self.epbcs = Conditions.from_conf(conf_epbc, self.domain.regions)

        if isinstance(lcbcs, Conditions):
            self.lcbcs = lcbcs

        else:
            conf_lcbc = get_default(lcbcs, self.conf.lcbcs)
            self.lcbcs = Conditions.from_conf(conf_lcbc, self.domain.regions)
Exemplo n.º 8
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    def _get_linear_combinationBCs(self, domain):
        """
        The right nodes are periodic with the left nodes but also displaced.

        Args:
          domain: an Sfepy domain

        Returns:
          the Sfepy boundary conditions

        """
        min_xyz = domain.get_mesh_bounding_box()[0]
        max_xyz = domain.get_mesh_bounding_box()[1]
        xplus_ = self._subdomain_func(x=(max_xyz[0], ))
        xminus_ = self._subdomain_func(x=(min_xyz[0], ))

        xplus = Function('xplus', xplus_)
        xminus = Function('xminus', xminus_)
        region_x_plus = domain.create_region('region_x_plus',
                                             'vertices by xplus',
                                             'facet',
                                             functions=Functions([xplus]))
        region_x_minus = domain.create_region('region_x_minus',
                                              'vertices by xminus',
                                              'facet',
                                              functions=Functions([xminus]))
        match_x_plane = Function('match_x_plane', per.match_x_plane)

        def shift_(ts, coors, region):
            return np.ones_like(coors[:, 0]) * \
                self.macro_strain * (max_xyz[0] - min_xyz[0])

        shift = Function('shift', shift_)
        lcbc = LinearCombinationBC('lcbc', [region_x_plus, region_x_minus],
                                   {'u.0': 'u.0'},
                                   match_x_plane,
                                   'shifted_periodic',
                                   arguments=(shift, ))

        return Conditions([lcbc])
Exemplo n.º 9
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def get_periodic_bcs(domain):
    """Get the periodic boundary conditions

    Args:
      domain: the Sfepy domain

    Returns:
      the boundary conditions and sfepy functions
    """
    zipped = lambda x, f: pipe(
        range(x,
              domain.get_mesh_bounding_box().shape[1]),
        map_(f(domain)),
        lambda x: zip(*x),
        list,
    )

    return pipe(
        (zipped(0, get_periodic_bc_yz), zipped(1, get_periodic_bc_x)),
        lambda x:
        (Conditions(x[0][0] + x[1][0]), Functions(x[0][1] + x[1][1])),
    )
Exemplo n.º 10
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def main():
    from sfepy import data_dir

    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('--diffusivity',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='diffusivity',
                      default=1e-5,
                      help=helps['diffusivity'])
    parser.add_option('--ic-max',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='ic_max',
                      default=2.0,
                      help=helps['ic_max'])
    parser.add_option('--order',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='order',
                      default=2,
                      help=helps['order'])
    parser.add_option('-r',
                      '--refine',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='refine',
                      default=0,
                      help=helps['refine'])
    parser.add_option('-p',
                      '--probe',
                      action="store_true",
                      dest='probe',
                      default=False,
                      help=helps['probe'])
    parser.add_option('-s',
                      '--show',
                      action="store_true",
                      dest='show',
                      default=False,
                      help=helps['show'])
    options, args = parser.parse_args()

    assert_((0 < options.order),
            'temperature approximation order must be at least 1!')

    output('using values:')
    output('  diffusivity:', options.diffusivity)
    output('  max. IC value:', options.ic_max)
    output('uniform mesh refinement level:', options.refine)

    mesh = Mesh.from_file(data_dir + '/meshes/3d/cylinder.mesh')
    domain = FEDomain('domain', mesh)

    if options.refine > 0:
        for ii in xrange(options.refine):
            output('refine %d...' % ii)
            domain = domain.refine()
            output('... %d nodes %d elements' %
                   (domain.shape.n_nod, domain.shape.n_el))

    omega = domain.create_region('Omega', 'all')
    left = domain.create_region('Left', 'vertices in x < 0.00001', 'facet')
    right = domain.create_region('Right', 'vertices in x > 0.099999', 'facet')

    field = Field.from_args('fu',
                            nm.float64,
                            'scalar',
                            omega,
                            approx_order=options.order)

    T = FieldVariable('T', 'unknown', field, history=1)
    s = FieldVariable('s', 'test', field, primary_var_name='T')

    m = Material('m', diffusivity=options.diffusivity * nm.eye(3))

    integral = Integral('i', order=2 * options.order)

    t1 = Term.new('dw_diffusion(m.diffusivity, s, T)',
                  integral,
                  omega,
                  m=m,
                  s=s,
                  T=T)
    t2 = Term.new('dw_volume_dot(s, dT/dt)', integral, omega, s=s, T=T)
    eq = Equation('balance', t1 + t2)
    eqs = Equations([eq])

    # Boundary conditions.
    ebc1 = EssentialBC('T1', left, {'T.0': 2.0})
    ebc2 = EssentialBC('T2', right, {'T.0': -2.0})

    # Initial conditions.
    def get_ic(coors, ic):
        x, y, z = coors.T
        return 2 - 40.0 * x + options.ic_max * nm.sin(4 * nm.pi * x / 0.1)

    ic_fun = Function('ic_fun', get_ic)
    ic = InitialCondition('ic', omega, {'T.0': ic_fun})

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({'is_linear': True}, lin_solver=ls, status=nls_status)

    pb = Problem('heat', equations=eqs, nls=nls, ls=ls)
    pb.set_bcs(ebcs=Conditions([ebc1, ebc2]))
    pb.set_ics(Conditions([ic]))

    tss = SimpleTimeSteppingSolver({
        't0': 0.0,
        't1': 100.0,
        'n_step': 11
    },
                                   problem=pb)
    tss.init_time()

    if options.probe:
        # Prepare probe data.
        probes, labels = gen_lines(pb)

        ev = pb.evaluate
        order = 2 * (options.order - 1)

        gfield = Field.from_args('gu',
                                 nm.float64,
                                 'vector',
                                 omega,
                                 approx_order=options.order - 1)
        dvel = FieldVariable('dvel',
                             'parameter',
                             gfield,
                             primary_var_name='(set-to-None)')
        cfield = Field.from_args('gu',
                                 nm.float64,
                                 'scalar',
                                 omega,
                                 approx_order=options.order - 1)
        component = FieldVariable('component',
                                  'parameter',
                                  cfield,
                                  primary_var_name='(set-to-None)')

        nls_options = {'eps_a': 1e-16, 'i_max': 1}

        if options.show:
            plt.ion()

    # Solve the problem using the time stepping solver.
    suffix = tss.ts.suffix
    for step, time, state in tss():
        if options.probe:
            # Probe the solution.
            dvel_qp = ev('ev_diffusion_velocity.%d.Omega(m.diffusivity, T)' %
                         order,
                         copy_materials=False,
                         mode='qp')
            project_by_component(dvel,
                                 dvel_qp,
                                 component,
                                 order,
                                 nls_options=nls_options)

            all_results = []
            for ii, probe in enumerate(probes):
                fig, results = probe_results(ii, T, dvel, probe, labels[ii])

                all_results.append(results)

            plt.tight_layout()
            fig.savefig('time_poisson_interactive_probe_%s.png' %
                        (suffix % step),
                        bbox_inches='tight')

            if options.show:
                plt.draw()

            for ii, results in enumerate(all_results):
                output('probe %d (%s):' % (ii, probes[ii].name))
                output.level += 2
                for key, res in ordered_iteritems(results):
                    output(key + ':')
                    val = res[1]
                    output('  min: %+.2e, mean: %+.2e, max: %+.2e' %
                           (val.min(), val.mean(), val.max()))
                output.level -= 2
Exemplo n.º 11
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bc2 = EssentialBC('Gamma_Right', gammaR, {'t.0': set_bc_fun})

bc3 = EssentialBC('Gamma_Top', gammaT, {'t.0': set_bc_fun})
bc4 = EssentialBC('Gamma_Bottom', gammaB, {'t.0': set_bc_fun})

ls = ScipyDirect({})

nls_status = IndexedStruct()
newtonConfig = {'i_max': 10, 'eps_a': 1e-10, 'eps_r': 1}
nls = Newton(newtonConfig, lin_solver=ls, status=nls_status)

pb = Problem('Poisson', equations=eqs, nls=nls, ls=ls)
pb.save_regions_as_groups('regions')

# pb.time_update(ebcs=Conditions([fix_u, t1, t2]))
pb.time_update(ebcs=Conditions([bc1, bc2, bc3, bc4]))

vec = pb.solve()
print nls_status

pb.save_state('customCylinder.vtk', vec)

# if options.show:
# view = Viewer('customCylinder.vtk')
# view(vector_mode='warp_norm', rel_scaling=2,
#      is_scalar_bar=True, is_wireframe=True)

solutionData = vec.vec.reshape(100, 100)
xGrid = mesh.coors[:, 0].reshape(100, 100)
yGrid = mesh.coors[:, 1].reshape(100, 100)
analyticSolution = np.sin(xGrid / np.pi) * np.sin(yGrid / np.pi)
Exemplo n.º 12
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def FarField(eltype,
             points,
             boundary,
             lcar,
             epsilon,
             meshfile,
             thickness=None,
             verbose=False):
    """
    This function determines a geometric factor F within a single element. 
    The element type can be triangular, quadrilateral, tetrahedral or 
    hexahedral. For these types eltype is set to  "CTRIA3", "CQUAD4"
    "CTETRA" and "CHEXA8" respectively. The vertices of the element are 
    provided in the input parameter points. The input parameter boundary is of 
    boolean type and has the same size as points. Those points which are
    part of the conductive interface CI are flagged True. Epsilon sets
    a tolerance to determine which mesh vertices are considered part of
    the FF boundary. The meshing of the element is stored in a location
    provided by meshfile.
    
    Parameters
    ----------
    
    eltype:   string
              'CTRIA3' for triangular surface elements,
              'CQUAD4' for quadrilateral surface elements,
              'CTETRA' for tetrahedral volume elements.
              'CHEXA8' for hexahedral volume elements.
    points:   array like
              Array containing the coordinates of the element
    boundary: array like
              Array containing the entries of the boundary points
    lcar:     float
              Characteristic length value provided to gmsh for mesh sizing.
    epsilon:  float
              Numerical tolerance on criterion for far field
              boundary
    meshfile: string
              Filename and location for storing temporary mesh file
    verbose:  boolean
              Indicate whether intermediate results should be displayed
              or not
         
    Returns
    -------
    : array like
        Array with boolean entries stating True for those items
        on the boundary and False otherwise
    """

    if verbose is True:
        output.set_output(quiet=False)
    else:
        output.set_output(quiet=True)

    if (eltype == "CTRIA3") or (eltype == "CQUAD4"):
        sdim = 2
    else:
        sdim = 3

    boundpnts = []
    for i in range(len(points)):
        if boundary[i]:
            boundpnts.append(points[i])

    mesh = sfedis.fem.Mesh.from_file(meshfile)

    domain = sfedis.fem.FEDomain('domain', mesh)

    c = sfedis.Material('c', val=1.0)

    omega = domain.create_region('Omega', 'all')

    if verbose is True:
        coors = mesh.coors
        fixed_vert = _is_on_bound(coors,
                                  bound=boundpnts,
                                  sdim=sdim,
                                  epsilon=epsilon)
        print "fixed vertices:"
        print fixed_vert

    is_on_bound = sfedis.Functions([
        sfedis.Function('_is_on_bound',
                        _is_on_bound,
                        extra_args={
                            'bound': boundpnts,
                            'sdim': sdim,
                            'epsilon': lcar / 100.
                        }),
    ])
    fixed = domain.create_region('fixed',
                                 'vertices by _is_on_bound',
                                 'facet',
                                 functions=is_on_bound,
                                 add_to_regions=True)

    field_t = sfedis.fem.Field.from_args('temperature',
                                         np.float64,
                                         'scalar',
                                         omega,
                                         approx_order=2)
    t = sfedis.FieldVariable('t', 'unknown', field_t, 1)
    s = sfedis.FieldVariable('s', 'test', field_t, 1, primary_var_name='t')

    integral = sfedis.Integral('i', order=4)

    term1 = Term.new('dw_laplace(s, t)', integral, omega, s=s, t=t)
    term2 = Term.new('dw_volume_integrate(c.val, s)',
                     integral,
                     omega,
                     c=c,
                     s=s)  # heat source term for 1st step of far field
    eq = sfedis.Equation('temperature', term1 - term2)
    eqs = sfedis.Equations([eq])

    t_fixed = EssentialBC('t_fixed', fixed, {'t.0': 0.0})

    ls = ScipyDirect({})
    nls = Newton({'i_max': 1, 'eps_a': 1e-10}, lin_solver=ls)

    pb = sfedis.Problem('temperature', equations=eqs, nls=nls, ls=ls)
    pb.time_update(ebcs=Conditions([
        t_fixed,
    ]))

    temperature = pb.solve()
    out = temperature.create_output_dict()

    if verbose is True:
        pb.save_state('result.vtk', out=out)
        view = Viewer('result.vtk')
        view(is_wireframe=True, rel_scaling=1, is_scalar_bar=True)
        print "Maximum temperature: %f" % np.max(out['t'].data)

    data = [i[0] for i in out['t'].data]

    FF = _get_far(eltype, points, data, mesh, sdim, epsilon)
    str1 = ''.join(str(v) + ', ' for v in FF)[:-2]
    try:
        far = domain.create_region('far',
                                   'vertex %s' % str1,
                                   'facet',
                                   add_to_regions=True)
    except Exception as e:
        print "Far field region creation failed!"
        print(e)
        t.reset()
        s.reset()
        return

    area_source = pb.evaluate('d_surface.3.far(t)')

    fluxval = 1.0 / (area_source)
    c2 = sfedis.Material(
        'c2', val=fluxval
    )  # So that total heat at the far field is 1W equally distributed over all elements

    term1A = Term.new('dw_laplace(c.val, s, t)',
                      integral,
                      omega,
                      c=c,
                      s=s,
                      t=t)
    term2A = Term.new('dw_surface_integrate(c2.val, s)',
                      integral,
                      far,
                      c2=c2,
                      s=s)
    eq2 = sfedis.Equation('temperature2', term1A - term2A)
    eqs2 = sfedis.Equations([eq2])

    pb2 = sfedis.Problem('temperature2', equations=eqs2, nls=nls, ls=ls)
    pb2.time_update(ebcs=Conditions([
        t_fixed,
    ]))

    temperature2 = pb2.solve()
    out2 = temperature2.create_output_dict()
    volume = pb2.evaluate('d_volume.3.Omega(t)')

    t_int = pb2.evaluate('ev_volume_integrate.3.Omega(t)')

    avg_t = t_int / volume
    F = 1.0 / avg_t

    if verbose is True:
        print "Average temperature: %f" % avg_t

    if thickness:
        'Correction factor 1e-3 is due to geometry in mm instead of m'
        F = F * thickness * 1e-3

    if verbose is True:
        pb.save_state('result.vtk', out=out2)
        view = Viewer('result.vtk')
        view(is_wireframe=True, rel_scaling=1, is_scalar_bar=True)

    t.reset()
    s.reset()

    return F
def create_local_problem(omega_gi, order):
    """
    Local problem definition using a domain corresponding to the global region
    `omega_gi`.
    """
    mesh = omega_gi.domain.mesh

    # All tasks have the whole mesh.
    bbox = mesh.get_bounding_box()
    min_x, max_x = bbox[:, 0]
    eps_x = 1e-8 * (max_x - min_x)

    mesh_i = Mesh.from_region(omega_gi, mesh, localize=True)
    domain_i = FEDomain('domain_i', mesh_i)
    omega_i = domain_i.create_region('Omega', 'all')

    gamma1_i = domain_i.create_region('Gamma1',
                                      'vertices in (x < %.10f)' %
                                      (min_x + eps_x),
                                      'facet',
                                      allow_empty=True)
    gamma2_i = domain_i.create_region('Gamma2',
                                      'vertices in (x > %.10f)' %
                                      (max_x - eps_x),
                                      'facet',
                                      allow_empty=True)

    field_i = Field.from_args('fu', nm.float64, 1, omega_i, approx_order=order)

    output('number of local field DOFs:', field_i.n_nod)

    u_i = FieldVariable('u_i', 'unknown', field_i)
    v_i = FieldVariable('v_i', 'test', field_i, primary_var_name='u_i')

    integral = Integral('i', order=2 * order)

    mat = Material('m', lam=10, mu=5)
    t1 = Term.new('dw_laplace(m.lam, v_i, u_i)',
                  integral,
                  omega_i,
                  m=mat,
                  v_i=v_i,
                  u_i=u_i)

    def _get_load(coors):
        val = nm.ones_like(coors[:, 0])
        for coor in coors.T:
            val *= nm.sin(4 * nm.pi * coor)
        return val

    def get_load(ts, coors, mode=None, **kwargs):
        if mode == 'qp':
            return {'val': _get_load(coors).reshape(coors.shape[0], 1, 1)}

    load = Material('load', function=Function('get_load', get_load))

    t2 = Term.new('dw_volume_lvf(load.val, v_i)',
                  integral,
                  omega_i,
                  load=load,
                  v_i=v_i)

    eq = Equation('balance', t1 - 100 * t2)
    eqs = Equations([eq])

    ebc1 = EssentialBC('ebc1', gamma1_i, {'u_i.all': 0.0})
    ebc2 = EssentialBC('ebc2', gamma2_i, {'u_i.all': 0.1})

    pb = Problem('problem_i', equations=eqs, active_only=False)
    pb.time_update(ebcs=Conditions([ebc1, ebc2]))
    pb.update_materials()

    return pb
Exemplo n.º 14
0
def main(argv=None):
    options = parse_args(argv=argv)

    # vvvvvvvvvvvvvvvv #
    approx_order = 2
    # ^^^^^^^^^^^^^^^^ #

    # Setup output names
    outputs_folder = options.output_dir

    domain_name = "domain_1D"
    problem_name = "iburgers_1D"
    output_folder = pjoin(outputs_folder, problem_name, str(approx_order))
    output_format = "vtk"
    save_timestn = 100
    clear_folder(pjoin(output_folder, "*." + output_format))
    configure_output({
        'output_screen':
        True,
        'output_log_name':
        pjoin(output_folder, f"last_run_{problem_name}_{approx_order}.txt")
    })

    # ------------
    # | Get mesh |
    # ------------
    X1 = 0.
    XN = 1.
    n_nod = 100
    n_el = n_nod - 1
    mesh = get_gen_1D_mesh_hook(X1, XN, n_nod).read(None)

    # -----------------------------
    # | Create problem components |
    # -----------------------------

    integral = Integral('i', order=approx_order * 2)
    domain = FEDomain(domain_name, mesh)
    omega = domain.create_region('Omega', 'all')
    left = domain.create_region('Gamma1', 'vertices in x == %.10f' % X1,
                                'vertex')
    right = domain.create_region('Gamma2', 'vertices in x == %.10f' % XN,
                                 'vertex')
    field = DGField('dgfu',
                    nm.float64,
                    'scalar',
                    omega,
                    approx_order=approx_order)

    u = FieldVariable('u', 'unknown', field, history=1)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    MassT = Term.new('dw_dot(v, u)', integral, omega, u=u, v=v)

    velo = nm.array(1.0)

    def adv_fun(u):
        vu = velo.T * u[..., None]
        return vu

    def adv_fun_d(u):
        v1 = velo.T * nm.ones(u.shape + (1, ))
        return v1

    burg_velo = velo.T / nm.linalg.norm(velo)

    def burg_fun(u):
        vu = burg_velo * u[..., None]**2
        return vu

    def burg_fun_d(u):
        v1 = 2 * burg_velo * u[..., None]
        return v1

    StiffT = Term.new('dw_ns_dot_grad_s(fun, fun_d, u[-1], v)',
                      integral,
                      omega,
                      u=u,
                      v=v,
                      fun=burg_fun,
                      fun_d=burg_fun_d)

    # alpha = Material('alpha', val=[.0])
    # FluxT = AdvectDGFluxTerm("adv_lf_flux(a.val, v, u)", "a.val, v,  u[-1]",
    #                          integral, omega, u=u, v=v, a=a, alpha=alpha)

    FluxT = Term.new('dw_dg_nonlinear_laxfrie_flux(fun, fun_d, v, u[-1])',
                     integral,
                     omega,
                     u=u,
                     v=v,
                     fun=burg_fun,
                     fun_d=burg_fun_d)

    eq = Equation('balance', MassT - StiffT + FluxT)
    eqs = Equations([eq])

    # ------------------------------
    # | Create boundary conditions |
    # ------------------------------
    left_fix_u = EssentialBC('left_fix_u', left, {'u.all': 1.0})
    right_fix_u = EssentialBC('right_fix_u', right, {'u.all': 0.0})

    # ----------------------------
    # | Create initial condition |
    # ----------------------------
    def ghump(x):
        """
        Nice gaussian.
        """
        return nm.exp(-200 * x**2)

    def ic_wrap(x, ic=None):
        return ghump(x - .3)

    ic_fun = Function('ic_fun', ic_wrap)
    ics = InitialCondition('ic', omega, {'u.0': ic_fun})

    # ------------------
    # | Create problem |
    # ------------------
    pb = Problem(problem_name,
                 equations=eqs,
                 conf=Struct(options={"save_times": save_timestn},
                             ics={},
                             ebcs={},
                             epbcs={},
                             lcbcs={},
                             materials={}),
                 active_only=False)
    pb.setup_output(output_dir=output_folder, output_format=output_format)
    pb.set_ics(Conditions([ics]))

    # ------------------
    # | Create limiter |
    # ------------------
    limiter = MomentLimiter1D

    # ---------------------------
    # | Set time discretization |
    # ---------------------------
    CFL = .2
    max_velo = nm.max(nm.abs(velo))
    t0 = 0
    t1 = .2
    dx = nm.min(mesh.cmesh.get_volumes(1))
    dt = dx / max_velo * CFL / (2 * approx_order + 1)
    tn = int(nm.ceil((t1 - t0) / dt))
    dtdx = dt / dx

    # ------------------
    # | Create solver |
    # ------------------
    ls = ScipyDirect({})
    nls_status = IndexedStruct()
    nls = Newton({'is_linear': True}, lin_solver=ls, status=nls_status)

    tss_conf = {
        't0': t0,
        't1': t1,
        'n_step': tn,
        'limiters': {
            "dgfu": limiter
        }
    }

    tss = TVDRK3StepSolver(tss_conf, nls=nls, context=pb, verbose=True)

    # ---------
    # | Solve |
    # ---------
    pb.set_solver(tss)
    state_end = pb.solve()

    output("Solved equation \n\n\t\t u_t - div(f(u))) = 0\n")
    output(f"With IC: {ic_fun.name}")
    # output("and EBCs: {}".format(pb.ebcs.names))
    # output("and EPBCS: {}".format(pb.epbcs.names))
    output("-------------------------------------")
    output(f"Approximation order is {approx_order}")
    output(f"Space divided into {mesh.n_el} cells, " +
           f"{len(mesh.coors)} steps, step size is {dx}")
    output(f"Time divided into {tn - 1} nodes, {tn} steps, step size is {dt}")
    output(f"CFL coefficient was {CFL} and " +
           f"order correction {1 / (2 * approx_order + 1)}")
    output(f"Courant number c = max(abs(u)) * dt/dx = {max_velo * dtdx}")
    output("------------------------------------------")
    output(f"Time stepping solver is {tss.name}")
    output(f"Limiter used: {limiter.name}")
    output("======================================")

    # ----------
    # | Plot 1D|
    # ----------
    if options.plot:
        load_and_plot_fun(output_folder, domain_name, t0, t1,
                          min(tn, save_timestn), ic_fun)
Exemplo n.º 15
0
ics = InitialCondition('ic', omega, {'u.0': ic_fun})

# ------------------
# | Create problem |
# ------------------
pb = Problem(problem_name,
             equations=eqs,
             conf=Struct(options={"save_times": save_timestn},
                         ics={},
                         ebcs={},
                         epbcs={},
                         lcbcs={},
                         materials={}),
             active_only=False)
pb.setup_output(output_dir=output_folder, output_format=output_format)
pb.set_ics(Conditions([ics]))

# ------------------
# | Create limiter |
# ------------------
limiter = MomentLimiter1D

# ---------------------------
# | Set time discretization |
# ---------------------------
CFL = .2
max_velo = nm.max(nm.abs(velo))
t0 = 0
t1 = .2
dx = nm.min(mesh.cmesh.get_volumes(1))
dt = dx / max_velo * CFL / (2 * approx_order + 1)
def main():
    parser = ArgumentParser(description=__doc__,
                            formatter_class=RawDescriptionHelpFormatter)
    parser.add_argument('--version', action='version', version='%(prog)s')
    parser.add_argument('-d',
                        '--dims',
                        metavar='dims',
                        action='store',
                        dest='dims',
                        default='[1.0, 1.0]',
                        help=helps['dims'])
    parser.add_argument('-c',
                        '--centre',
                        metavar='centre',
                        action='store',
                        dest='centre',
                        default='[0.0, 0.0]',
                        help=helps['centre'])
    parser.add_argument('-s',
                        '--shape',
                        metavar='shape',
                        action='store',
                        dest='shape',
                        default='[11, 11]',
                        help=helps['shape'])
    parser.add_argument('-b',
                        '--bc-kind',
                        metavar='kind',
                        action='store',
                        dest='bc_kind',
                        choices=['free', 'cantilever', 'fixed'],
                        default='free',
                        help=helps['bc_kind'])
    parser.add_argument('-a',
                        '--axis',
                        metavar='0, ..., dim, or -1',
                        type=int,
                        action='store',
                        dest='axis',
                        default=-1,
                        help=helps['axis'])
    parser.add_argument('--young',
                        metavar='float',
                        type=float,
                        action='store',
                        dest='young',
                        default=200e+9,
                        help=helps['young'])
    parser.add_argument('--poisson',
                        metavar='float',
                        type=float,
                        action='store',
                        dest='poisson',
                        default=0.3,
                        help=helps['poisson'])
    parser.add_argument('--density',
                        metavar='float',
                        type=float,
                        action='store',
                        dest='density',
                        default=7800.0,
                        help=helps['density'])
    parser.add_argument('--order',
                        metavar='int',
                        type=int,
                        action='store',
                        dest='order',
                        default=1,
                        help=helps['order'])
    parser.add_argument('-n',
                        '--n-eigs',
                        metavar='int',
                        type=int,
                        action='store',
                        dest='n_eigs',
                        default=6,
                        help=helps['n_eigs'])
    parser.add_argument('-i',
                        '--ignore',
                        metavar='int',
                        type=int,
                        action='store',
                        dest='ignore',
                        default=None,
                        help=helps['ignore'])
    parser.add_argument('--solver', metavar='solver', action='store',
                        dest='solver',
                        default= \
                        "eig.scipy,method:'eigh',tol:1e-5,maxiter:1000",
                        help=helps['solver'])
    parser.add_argument('--show',
                        action="store_true",
                        dest='show',
                        default=False,
                        help=helps['show'])
    #parser.add_argument('filename', nargs='?', default=None)
    #read block.mesh
    #parser.add_argument('filename', nargs='?', default="platehexat200mm.mesh")
    parser.add_argument('filename', nargs='?', default="block_1m.mesh")
    options = parser.parse_args()

    aux = options.solver.split(',')
    kwargs = {}
    for option in aux[1:]:
        key, val = option.split(':')
        kwargs[key.strip()] = eval(val)
    eig_conf = Struct(name='evp', kind=aux[0], **kwargs)

    output('using values:')
    output("  Young's modulus:", options.young)
    output("  Poisson's ratio:", options.poisson)
    output('  density:', options.density)
    output('displacement field approximation order:', options.order)
    output('requested %d eigenvalues' % options.n_eigs)
    output('using eigenvalue problem solver:', eig_conf.kind)
    output.level += 1
    for key, val in six.iteritems(kwargs):
        output('%s: %r' % (key, val))
    output.level -= 1

    assert_((0.0 < options.poisson < 0.5),
            "Poisson's ratio must be in ]0, 0.5[!")
    assert_((0 < options.order),
            'displacement approximation order must be at least 1!')

    filename = options.filename
    if filename is not None:
        mesh = Mesh.from_file(filename)
        dim = mesh.dim
        dims = nm.diff(mesh.get_bounding_box(), axis=0)

    else:
        dims = nm.array(eval(options.dims), dtype=nm.float64)
        dim = len(dims)

        centre = nm.array(eval(options.centre), dtype=nm.float64)[:dim]
        shape = nm.array(eval(options.shape), dtype=nm.int32)[:dim]

        output('dimensions:', dims)
        output('centre:    ', centre)
        output('shape:     ', shape)

        mesh = gen_block_mesh(dims, shape, centre, name='mesh')

    output('axis:      ', options.axis)
    assert_((-dim <= options.axis < dim), 'invalid axis value!')

    eig_solver = Solver.any_from_conf(eig_conf)

    # Build the problem definition.
    domain = FEDomain('domain', mesh)

    bbox = domain.get_mesh_bounding_box()
    min_coor, max_coor = bbox[:, options.axis]
    eps = 1e-8 * (max_coor - min_coor)
    ax = 'xyz'[:dim][options.axis]

    omega = domain.create_region('Omega', 'all')
    """
    bottom = domain.create_region('Bottom',
                                  'vertices in (%s < %.10f)'
                                  % (ax, min_coor + eps),
                                  'facet')

    bottom_top = domain.create_region('BottomTop',
                                      'r.Bottom +v vertices in (%s > %.10f)'
                                      % (ax, max_coor - eps),
                                      'facet')
    """
    #import pdb; pdb.set_trace()
    left = domain.create_region('left', 'vertices in (x < -0.49)', 'facet')

    field = Field.from_args('fu',
                            nm.float64,
                            'vector',
                            omega,
                            approx_order=options.order)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    mtx_d = stiffness_from_youngpoisson(dim, options.young, options.poisson)

    m = Material('m', D=mtx_d, rho=options.density)

    integral = Integral('i', order=2 * options.order)

    t1 = Term.new('dw_lin_elastic(m.D, v, u)', integral, omega, m=m, v=v, u=u)
    t2 = Term.new('dw_volume_dot(m.rho, v, u)', integral, omega, m=m, v=v, u=u)
    eq1 = Equation('stiffness', t1)
    eq2 = Equation('mass', t2)
    lhs_eqs = Equations([eq1, eq2])

    pb = Problem('modal', equations=lhs_eqs)
    """
    if options.bc_kind == 'free':
        pb.time_update()
        n_rbm = dim * (dim + 1) // 2

    elif options.bc_kind == 'cantilever':
        fixed = EssentialBC('Fixed', bottom, {'u.all' : 0.0})
        pb.time_update(ebcs=Conditions([fixed]))
        n_rbm = 0

    elif options.bc_kind == 'fixed':
        fixed = EssentialBC('Fixed', bottom_top, {'u.all' : 0.0})
        pb.time_update(ebcs=Conditions([fixed]))
        n_rbm = 0

    else:
        raise ValueError('unsupported BC kind! (%s)' % options.bc_kind)

    if options.ignore is not None:
        n_rbm = options.ignore
    """
    fixed = EssentialBC('Fixed', left, {'u.all': 0.0})
    pb.time_update(ebcs=Conditions([fixed]))
    n_rbm = 0

    pb.update_materials()

    # Assemble stiffness and mass matrices.
    mtx_k = eq1.evaluate(mode='weak', dw_mode='matrix', asm_obj=pb.mtx_a)
    mtx_m = mtx_k.copy()
    mtx_m.data[:] = 0.0
    mtx_m = eq2.evaluate(mode='weak', dw_mode='matrix', asm_obj=mtx_m)

    try:
        eigs, svecs = eig_solver(mtx_k,
                                 mtx_m,
                                 options.n_eigs + n_rbm,
                                 eigenvectors=True)

    except sla.ArpackNoConvergence as ee:
        eigs = ee.eigenvalues
        svecs = ee.eigenvectors
        output('only %d eigenvalues converged!' % len(eigs))

    output('%d eigenvalues converged (%d ignored as rigid body modes)' %
           (len(eigs), n_rbm))

    eigs = eigs[n_rbm:]
    svecs = svecs[:, n_rbm:]

    omegas = nm.sqrt(eigs)
    freqs = omegas / (2 * nm.pi)

    output('number |         eigenvalue |  angular frequency '
           '|          frequency')
    for ii, eig in enumerate(eigs):
        output('%6d | %17.12e | %17.12e | %17.12e' %
               (ii + 1, eig, omegas[ii], freqs[ii]))

    # Make full eigenvectors (add DOFs fixed by boundary conditions).
    variables = pb.get_variables()

    vecs = nm.empty((variables.di.ptr[-1], svecs.shape[1]), dtype=nm.float64)
    for ii in range(svecs.shape[1]):
        vecs[:, ii] = variables.make_full_vec(svecs[:, ii])

    # Save the eigenvectors.
    out = {}
    state = pb.create_state()
    for ii in range(eigs.shape[0]):
        state.set_full(vecs[:, ii])
        aux = state.create_output_dict()
        strain = pb.evaluate('ev_cauchy_strain.i.Omega(u)',
                             integrals=Integrals([integral]),
                             mode='el_avg',
                             verbose=False)
        out['u%03d' % ii] = aux.popitem()[1]
        out['strain%03d' % ii] = Struct(mode='cell', data=strain)

    pb.save_state('eigenshapes.vtk', out=out)
    pb.save_regions_as_groups('regions')

    if len(eigs) and options.show:
        # Show the solution. If the approximation order is greater than 1, the
        # extra DOFs are simply thrown away.
        from sfepy.postprocess.viewer import Viewer
        from sfepy.postprocess.domain_specific import DomainSpecificPlot

        scaling = 0.05 * dims.max() / nm.abs(vecs).max()

        ds = {}
        for ii in range(eigs.shape[0]):
            pd = DomainSpecificPlot('plot_displacements', [
                'rel_scaling=%s' % scaling, 'color_kind="tensors"',
                'color_name="strain%03d"' % ii
            ])
            ds['u%03d' % ii] = pd

        view = Viewer('eigenshapes.vtk')
        view(domain_specific=ds,
             only_names=sorted(ds.keys()),
             is_scalar_bar=False,
             is_wireframe=True)
Exemplo n.º 17
0
def main():
    parser = ArgumentParser(description=__doc__.rstrip(),
                            formatter_class=RawDescriptionHelpFormatter)
    parser.add_argument('-o',
                        '--output-dir',
                        default='.',
                        help=helps['output_dir'])
    parser.add_argument('--R1',
                        metavar='R1',
                        action='store',
                        dest='R1',
                        default='0.5',
                        help=helps['R1'])
    parser.add_argument('--R2',
                        metavar='R2',
                        action='store',
                        dest='R2',
                        default='1.0',
                        help=helps['R2'])
    parser.add_argument('--C1',
                        metavar='C1',
                        action='store',
                        dest='C1',
                        default='0.0,0.0',
                        help=helps['C1'])
    parser.add_argument('--C2',
                        metavar='C2',
                        action='store',
                        dest='C2',
                        default='0.0,0.0',
                        help=helps['C2'])
    parser.add_argument('--order',
                        metavar='int',
                        type=int,
                        action='store',
                        dest='order',
                        default=2,
                        help=helps['order'])
    parser.add_argument('-v',
                        '--viewpatch',
                        action='store_true',
                        dest='viewpatch',
                        default=False,
                        help=helps['viewpatch'])
    options = parser.parse_args()

    # Creation of the NURBS-patch with igakit
    R1 = eval(options.R1)
    R2 = eval(options.R2)
    C1 = list(eval(options.C1))
    C2 = list(eval(options.C2))
    order = options.order
    viewpatch = options.viewpatch
    create_patch(R1, R2, C1, C2, order=order, viewpatch=viewpatch)

    # Setting a Domain instance
    filename_domain = data_dir + '/meshes/iga/concentric_circles.iga'
    domain = IGDomain.from_file(filename_domain)

    # Sub-domains
    omega = domain.create_region('Omega', 'all')
    Gamma_out = domain.create_region('Gamma_out',
                                     'vertices of set xi01',
                                     kind='facet')
    Gamma_in = domain.create_region('Gamma_in',
                                    'vertices of set xi00',
                                    kind='facet')

    # Field (featuring order elevation)
    order_increase = order - domain.nurbs.degrees[0]
    order_increase *= int(order_increase > 0)
    field = Field.from_args('fu',
                            nm.float64,
                            'scalar',
                            omega,
                            approx_order='iga',
                            space='H1',
                            poly_space_base='iga')

    # Variables
    u = FieldVariable('u', 'unknown', field)  # unknown function
    v = FieldVariable('v', 'test', field,
                      primary_var_name='u')  # test function

    # Integral
    integral = Integral('i', order=2 * field.approx_order)

    # Term
    t = Term.new('dw_laplace( v, u )', integral, omega, v=v, u=u)

    # Equation
    eq = Equation('laplace', t)
    eqs = Equations([eq])

    # Boundary Conditions
    u_in = EssentialBC('u_in', Gamma_in, {'u.all': 7.0})
    u_out = EssentialBC('u_out', Gamma_out, {'u.all': 3.0})

    # solvers
    ls = ScipyDirect({})
    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    # problem instance
    pb = Problem('potential', equations=eqs, active_only=True)

    # Set boundary conditions
    pb.set_bcs(ebcs=Conditions([u_in, u_out]))

    # solving
    pb.set_solver(nls)
    status = IndexedStruct()
    state = pb.solve(status=status, save_results=True, verbose=True)

    # Saving the results to a classic VTK file
    filename = os.path.join(options.output_dir, 'concentric_circles.vtk')
    ensure_path(filename)
    pb.save_state(filename, state)
Exemplo n.º 18
0
def create_local_problem(omega_gi, orders):
    """
    Local problem definition using a domain corresponding to the global region
    `omega_gi`.
    """
    order_u, order_p = orders

    mesh = omega_gi.domain.mesh

    # All tasks have the whole mesh.
    bbox = mesh.get_bounding_box()
    min_x, max_x = bbox[:, 0]
    eps_x = 1e-8 * (max_x - min_x)

    min_y, max_y = bbox[:, 1]
    eps_y = 1e-8 * (max_y - min_y)

    mesh_i = Mesh.from_region(omega_gi, mesh, localize=True)
    domain_i = FEDomain('domain_i', mesh_i)
    omega_i = domain_i.create_region('Omega', 'all')

    gamma1_i = domain_i.create_region('Gamma1',
                                      'vertices in (x < %.10f)'
                                      % (min_x + eps_x),
                                      'facet', allow_empty=True)
    gamma2_i = domain_i.create_region('Gamma2',
                                      'vertices in (x > %.10f)'
                                      % (max_x - eps_x),
                                      'facet', allow_empty=True)
    gamma3_i = domain_i.create_region('Gamma3',
                                      'vertices in (y < %.10f)'
                                      % (min_y + eps_y),
                                      'facet', allow_empty=True)

    field1_i = Field.from_args('fu', nm.float64, mesh.dim, omega_i,
                               approx_order=order_u)

    field2_i = Field.from_args('fp', nm.float64, 1, omega_i,
                               approx_order=order_p)

    output('field 1: number of local DOFs:', field1_i.n_nod)
    output('field 2: number of local DOFs:', field2_i.n_nod)

    u_i = FieldVariable('u_i', 'unknown', field1_i, order=0)
    v_i = FieldVariable('v_i', 'test', field1_i, primary_var_name='u_i')
    p_i = FieldVariable('p_i', 'unknown', field2_i, order=1)
    q_i = FieldVariable('q_i', 'test', field2_i, primary_var_name='p_i')

    if mesh.dim == 2:
        alpha = 1e2 * nm.array([[0.132], [0.132], [0.092]])

    else:
        alpha = 1e2 * nm.array([[0.132], [0.132], [0.132],
                                [0.092], [0.092], [0.092]])

    mat = Material('m', D=stiffness_from_lame(mesh.dim, lam=10, mu=5),
                   k=1, alpha=alpha)
    integral = Integral('i', order=2*(max(order_u, order_p)))

    t11 = Term.new('dw_lin_elastic(m.D, v_i, u_i)',
                   integral, omega_i, m=mat, v_i=v_i, u_i=u_i)
    t12 = Term.new('dw_biot(m.alpha, v_i, p_i)',
                   integral, omega_i, m=mat, v_i=v_i, p_i=p_i)
    t21 = Term.new('dw_biot(m.alpha, u_i, q_i)',
                   integral, omega_i, m=mat, u_i=u_i, q_i=q_i)
    t22 = Term.new('dw_laplace(m.k, q_i, p_i)',
                   integral, omega_i, m=mat, q_i=q_i, p_i=p_i)

    eq1 = Equation('eq1', t11 - t12)
    eq2 = Equation('eq1', t21 + t22)
    eqs = Equations([eq1, eq2])

    ebc1 = EssentialBC('ebc1', gamma1_i, {'u_i.all' : 0.0})
    ebc2 = EssentialBC('ebc2', gamma2_i, {'u_i.0' : 0.05})
    def bc_fun(ts, coors, **kwargs):
        val = 0.3 * nm.sin(4 * nm.pi * (coors[:, 0] - min_x) / (max_x - min_x))
        return val

    fun = Function('bc_fun', bc_fun)
    ebc3 = EssentialBC('ebc3', gamma3_i, {'p_i.all' : fun})

    pb = Problem('problem_i', equations=eqs, active_only=False)
    pb.time_update(ebcs=Conditions([ebc1, ebc2, ebc3]))
    pb.update_materials()

    return pb
Exemplo n.º 19
0
    # vol = np.loadtxt('tmp_vol.dat')
    #
    # vm_stresses[i, 0] = np.sum(vms * vol) / np.sum(vol)
    # vm_stresses[i, 1] = np.max(vms)
    #
    # pb.save_state('voronoi_foam_%f.vtk' % z_displacement, state)
    #
    ### Solvers ###
    ls = ScipyDirect({})
    nls_status = IndexedStruct()
    nls = Newton({'i_max': 20}, lin_solver=ls, status=nls_status)

    ### Problem ###
    pb = Problem('hyper', equations=equations)
    pb.set_bcs(ebcs=ebcs)
    pb.set_ics(ics=Conditions([]))
    tss = SimpleTimeSteppingSolver(ts, nls=nls, context=pb)
    pb.set_solver(tss)

    ### Solution ###
    axial_stress = []
    axial_displacement = []

    def stress_strain_fun(*args, **kwargs):
        return stress_strain(*args,
                             order=order,
                             global_stress=axial_stress,
                             global_displacement=axial_displacement,
                             **kwargs)

    pb.solve(save_results=True, post_process_hook=stress_strain_fun)
def main():
    parser = ArgumentParser(description=__doc__.rstrip(),
                            formatter_class=RawDescriptionHelpFormatter)
    parser.add_argument('output_dir', help=helps['output_dir'])
    parser.add_argument('--dims', metavar='dims',
                        action='store', dest='dims',
                        default='1.0,1.0,1.0', help=helps['dims'])
    parser.add_argument('--shape', metavar='shape',
                        action='store', dest='shape',
                        default='7,7,7', help=helps['shape'])
    parser.add_argument('--centre', metavar='centre',
                        action='store', dest='centre',
                        default='0.0,0.0,0.0', help=helps['centre'])
    parser.add_argument('-3', '--3d',
                        action='store_true', dest='is_3d',
                        default=False, help=helps['3d'])
    parser.add_argument('--order', metavar='int', type=int,
                        action='store', dest='order',
                        default=1, help=helps['order'])
    options = parser.parse_args()

    dim = 3 if options.is_3d else 2
    dims = nm.array(eval(options.dims), dtype=nm.float64)[:dim]
    shape = nm.array(eval(options.shape), dtype=nm.int32)[:dim]
    centre = nm.array(eval(options.centre), dtype=nm.float64)[:dim]

    output('dimensions:', dims)
    output('shape:     ', shape)
    output('centre:    ', centre)

    mesh0 = gen_block_mesh(dims, shape, centre, name='block-fem',
                           verbose=True)
    domain0 = FEDomain('d', mesh0)

    bbox = domain0.get_mesh_bounding_box()
    min_x, max_x = bbox[:, 0]
    eps = 1e-8 * (max_x - min_x)

    cnt = (shape[0] - 1) // 2
    g0 = 0.5 * dims[0]
    grading = nm.array([g0 / 2**ii for ii in range(cnt)]) + eps + centre[0] - g0

    domain, subs = refine_towards_facet(domain0, grading, 'x <')

    omega = domain.create_region('Omega', 'all')

    gamma1 = domain.create_region('Gamma1',
                                  'vertices in (x < %.10f)' % (min_x + eps),
                                  'facet')
    gamma2 = domain.create_region('Gamma2',
                                  'vertices in (x > %.10f)' % (max_x - eps),
                                  'facet')

    field = Field.from_args('fu', nm.float64, 1, omega,
                            approx_order=options.order)

    if subs is not None:
        field.substitute_dofs(subs)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    integral = Integral('i', order=2*options.order)

    t1 = Term.new('dw_laplace(v, u)',
                  integral, omega, v=v, u=u)
    eq = Equation('eq', t1)
    eqs = Equations([eq])

    def u_fun(ts, coors, bc=None, problem=None):
        """
        Define a displacement depending on the y coordinate.
        """
        if coors.shape[1] == 2:
            min_y, max_y = bbox[:, 1]
            y = (coors[:, 1] - min_y) / (max_y - min_y)

            val = (max_y - min_y) * nm.cos(3 * nm.pi * y)

        else:
            min_y, max_y = bbox[:, 1]
            min_z, max_z = bbox[:, 2]
            y = (coors[:, 1] - min_y) / (max_y - min_y)
            z = (coors[:, 2] - min_z) / (max_z - min_z)

            val = ((max_y - min_y) * (max_z - min_z)
                   * nm.cos(3 * nm.pi * y) * (1.0 + 3.0 * (z - 0.5)**2))

        return val

    bc_fun = Function('u_fun', u_fun)
    fix1 = EssentialBC('shift_u', gamma1, {'u.0' : bc_fun})
    fix2 = EssentialBC('fix2', gamma2, {'u.all' : 0.0})

    ls = ScipyDirect({})

    nls = Newton({}, lin_solver=ls)

    pb = Problem('heat', equations=eqs, nls=nls, ls=ls)

    pb.time_update(ebcs=Conditions([fix1, fix2]))
    state = pb.solve()

    if subs is not None:
        field.restore_dofs()

    filename = os.path.join(options.output_dir, 'hanging.vtk')
    ensure_path(filename)

    pb.save_state(filename, state)
    if options.order > 1:
        pb.save_state(filename, state, linearization=Struct(kind='adaptive',
                                                            min_level=0,
                                                            max_level=8,
                                                            eps=1e-3))
Exemplo n.º 21
0
    def test_epbcs(self):
        from sfepy.discrete import Function, Functions
        from sfepy.discrete.conditions import Conditions, PeriodicBC
        from sfepy.discrete.common.dof_info import expand_nodes_to_equations
        from sfepy.discrete.fem.periodic import match_y_line

        variables = self.variables
        regions = self.problem.domain.regions

        match_y_line = Function('match_y_line', match_y_line)
        pbc = PeriodicBC('pbc', [regions['LeftStrip'], regions['RightStrip']],
                         {'u.[1,0]': 'u.[0,1]'},
                         match='match_y_line')

        functions = Functions([match_y_line])

        epbcs = Conditions([pbc])
        variables.equation_mapping(ebcs=None,
                                   epbcs=epbcs,
                                   ts=None,
                                   functions=functions)

        vec = init_vec(variables)
        variables.apply_ebc(vec)

        var = variables['u']
        var_bcs = epbcs.group_by_variables()['u']
        bc = var_bcs['pbc']
        bc.canonize_dof_names(var.dofs)

        nods0 = var.field.get_dofs_in_region(bc.regions[0])
        nods1 = var.field.get_dofs_in_region(bc.regions[1])

        coors0 = var.field.get_coor(nods0)
        coors1 = var.field.get_coor(nods1)
        i0, i1 = match_y_line(coors0, coors1)

        eq0 = expand_nodes_to_equations(nods0[i0], bc.dofs[0], var.dofs)
        eq1 = expand_nodes_to_equations(nods1[i1], bc.dofs[1], var.dofs)

        ok = True

        _ok = len(nm.setdiff1d(eq0, var.eq_map.master)) == 0
        if not _ok:
            self.report('master equations mismatch! (set(%s) == set(%s))' %
                        (eq0, var.eq_map.master))
        ok = ok and _ok

        _ok = len(nm.setdiff1d(eq1, var.eq_map.slave)) == 0
        if not _ok:
            self.report('slave equations mismatch! (set(%s) == set(%s))' %
                        (eq1, var.eq_map.slave))
        ok = ok and _ok

        off = variables.di.indx['u'].start
        _ok = nm.allclose(vec[off + eq0], vec[off + eq1], atol=1e-14, rtol=0.0)
        if not _ok:
            self.report('periodicity test failed! (%s == %s)' %
                        (vec[off + eq0], vec[off + eq0]))
        ok = ok and _ok

        return ok
Exemplo n.º 22
0
    def test_solving(self):
        from sfepy.base.base import IndexedStruct
        from sfepy.discrete import (FieldVariable, Material, Problem, Function,
                                    Equation, Equations, Integral)
        from sfepy.discrete.conditions import Conditions, EssentialBC
        from sfepy.terms import Term
        from sfepy.solvers.ls import ScipyDirect
        from sfepy.solvers.nls import Newton
        from sfepy.mechanics.matcoefs import stiffness_from_lame

        u = FieldVariable('u', 'unknown', self.field)
        v = FieldVariable('v', 'test', self.field, primary_var_name='u')

        m = Material('m', D=stiffness_from_lame(self.dim, 1.0, 1.0))
        f = Material('f', val=[[0.02], [0.01]])

        bc_fun = Function('fix_u_fun',
                          fix_u_fun,
                          extra_args={'extra_arg': 'hello'})

        fix_u = EssentialBC('fix_u', self.gamma1, {'u.all': bc_fun})
        shift_u = EssentialBC('shift_u', self.gamma2, {'u.0': 0.1})

        integral = Integral('i', order=3)

        t1 = Term.new('dw_lin_elastic(m.D, v, u)',
                      integral,
                      self.omega,
                      m=m,
                      v=v,
                      u=u)

        t2 = Term.new('dw_volume_lvf(f.val, v)',
                      integral,
                      self.omega,
                      f=f,
                      v=v)

        eq = Equation('balance', t1 + t2)
        eqs = Equations([eq])

        ls = ScipyDirect({})

        nls_status = IndexedStruct()
        nls = Newton({}, lin_solver=ls, status=nls_status)

        pb = Problem('elasticity', equations=eqs)
        ## pb.save_regions_as_groups('regions')

        pb.set_bcs(ebcs=Conditions([fix_u, shift_u]))
        pb.set_solver(nls)

        state = pb.solve()

        name = op.join(self.options.out_dir, 'test_high_level_solving.vtk')
        pb.save_state(name, state)

        ok = nls_status.condition == 0
        if not ok:
            self.report('solver did not converge!')

        _ok = state.has_ebc()
        if not _ok:
            self.report('EBCs violated!')

        ok = ok and _ok

        return ok
Exemplo n.º 23
0
    fix_bot = EssentialBC('fix_bot', bot, {'u.all': 0.0})
    fix_top = EssentialBC('fix_top', top, {
        'u.[0,1]': 0.0,
        'u.[2]': -z_displacement
    })

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)
    # 'i_max': 1, 'eps_a': 1e-10

    pb = Problem('elasticity', equations=eqs)
    pb.save_regions_as_groups('regions')

    pb.set_bcs(ebcs=Conditions([fix_bot, fix_top]))

    pb.set_solver(nls)

    status = IndexedStruct()
    state = pb.solve(status=status)

    strain = pb.evaluate('ev_cauchy_strain.2.Omega(u)', u=u, mode='el_avg')
    stress = pb.evaluate('ev_cauchy_stress.2.Omega(m.D, u)',
                         m=m,
                         u=u,
                         mode='el_avg')
    vms = get_von_mises_stress(stress.squeeze())
    np.savetxt('tmp_vms.dat', vms)
    vms = np.loadtxt('tmp_vms.dat')
Exemplo n.º 24
0
 def _get_displacementBCs(self, domain):
     shift_points_BC = self._get_shift_displacementsBCs(domain)
     fix_points_BC = self._get_fixed_displacementsBCs(domain)
     return Conditions([fix_points_BC, shift_points_BC])
Exemplo n.º 25
0
def solve_problem(shape, dims, young, poisson, force, transform=None):
    domain = make_domain(dims[:2], shape, transform=transform)

    omega = domain.regions['Omega']
    gamma1 = domain.regions['Gamma1']
    gamma2 = domain.regions['Gamma2']

    field = Field.from_args('fu',
                            nm.float64,
                            6,
                            omega,
                            approx_order=1,
                            poly_space_base='shell10x')
    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    thickness = dims[2]
    if transform is None:
        pload = [[0.0, 0.0, force / shape[1], 0.0, 0.0, 0.0]] * shape[1]

    elif transform == 'bend':
        pload = [[force / shape[1], 0.0, 0.0, 0.0, 0.0, 0.0]] * shape[1]

    elif transform == 'twist':
        pload = [[0.0, force / shape[1], 0.0, 0.0, 0.0, 0.0]] * shape[1]

    m = Material('m',
                 D=sh.create_elastic_tensor(young=young, poisson=poisson),
                 values={'.drill': 1e-7})
    load = Material('load', values={'.val': pload})

    aux = Integral('i', order=3)
    qp_coors, qp_weights = aux.get_qp('3_8')
    qp_coors[:, 2] = thickness * (qp_coors[:, 2] - 0.5)
    qp_weights *= thickness

    integral = Integral('i',
                        coors=qp_coors,
                        weights=qp_weights,
                        order='custom')

    t1 = Term.new('dw_shell10x(m.D, m.drill, v, u)',
                  integral,
                  omega,
                  m=m,
                  v=v,
                  u=u)
    t2 = Term.new('dw_point_load(load.val, v)',
                  integral,
                  gamma2,
                  load=load,
                  v=v)
    eq = Equation('balance', t1 - t2)
    eqs = Equations([eq])

    fix_u = EssentialBC('fix_u', gamma1, {'u.all': 0.0})

    ls = use_first_available([(MUMPSSolver, {}), (ScipyDirect, {})])

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    pb = Problem('elasticity with shell10x', equations=eqs)
    pb.set_bcs(ebcs=Conditions([fix_u]))
    pb.set_solver(nls)

    state = pb.solve()

    return pb, state, u, gamma2
Exemplo n.º 26
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def run(domain, order):
    omega = domain.create_region('Omega', 'all')
    bbox = domain.get_mesh_bounding_box()
    min_x, max_x = bbox[:, 0]
    min_y, max_y = bbox[:, 1]
    eps = 1e-8 * (max_x - min_x)
    gamma1 = domain.create_region('Gamma1',
                                  'vertices in (x < %.10f)' % (min_x + eps),
                                  'facet')
    gamma2 = domain.create_region('Gamma2',
                                  'vertices in (x > %.10f)' % (max_x - eps),
                                  'facet')
    gamma3 = domain.create_region('Gamma3',
                                  'vertices in y < %.10f' % (min_y + eps),
                                  'facet')
    gamma4 = domain.create_region('Gamma4',
                                  'vertices in y > %.10f' % (max_y - eps),
                                  'facet')

    field = Field.from_args('fu', nm.float64, 1, omega, approx_order=order)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    integral = Integral('i', order=2 * order)

    t1 = Term.new('dw_laplace(v, u)', integral, omega, v=v, u=u)
    eq = Equation('eq', t1)
    eqs = Equations([eq])

    fix1 = EssentialBC('fix1', gamma1, {'u.0': 0.4})
    fix2 = EssentialBC('fix2', gamma2, {'u.0': 0.0})

    def get_shift(ts, coors, region):
        return nm.ones_like(coors[:, 0])

    dof_map_fun = Function('dof_map_fun', per.match_x_line)
    shift_fun = Function('shift_fun', get_shift)

    sper = LinearCombinationBC('sper', [gamma3, gamma4], {'u.0': 'u.0'},
                               dof_map_fun,
                               'shifted_periodic',
                               arguments=(shift_fun, ))

    ls = ScipyDirect({})

    pb = Problem('laplace', equations=eqs, auto_solvers=None)

    pb.time_update(ebcs=Conditions([fix1, fix2]), lcbcs=Conditions([sper]))

    ev = pb.get_evaluator()
    nls = Newton({},
                 lin_solver=ls,
                 fun=ev.eval_residual,
                 fun_grad=ev.eval_tangent_matrix)

    pb.set_solver(nls)

    state = pb.solve()

    return pb, state
Exemplo n.º 27
0
def main():
    from sfepy import data_dir

    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('-s',
                      '--show',
                      action="store_true",
                      dest='show',
                      default=False,
                      help=help['show'])
    options, args = parser.parse_args()

    mesh = Mesh.from_file(data_dir + '/meshes/2d/rectangle_tri.mesh')
    domain = FEDomain('domain', mesh)

    min_x, max_x = domain.get_mesh_bounding_box()[:, 0]
    eps = 1e-8 * (max_x - min_x)
    omega = domain.create_region('Omega', 'all')
    gamma1 = domain.create_region('Gamma1',
                                  'vertices in x < %.10f' % (min_x + eps),
                                  'facet')
    gamma2 = domain.create_region('Gamma2',
                                  'vertices in x > %.10f' % (max_x - eps),
                                  'facet')

    field = Field.from_args('fu', nm.float64, 'vector', omega, approx_order=2)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    m = Material('m', D=stiffness_from_lame(dim=2, lam=1.0, mu=1.0))
    f = Material('f', val=[[0.02], [0.01]])

    integral = Integral('i', order=3)

    t1 = Term.new('dw_lin_elastic(m.D, v, u)', integral, omega, m=m, v=v, u=u)
    t2 = Term.new('dw_volume_lvf(f.val, v)', integral, omega, f=f, v=v)
    eq = Equation('balance', t1 + t2)
    eqs = Equations([eq])

    fix_u = EssentialBC('fix_u', gamma1, {'u.all': 0.0})

    bc_fun = Function('shift_u_fun', shift_u_fun, extra_args={'shift': 0.01})
    shift_u = EssentialBC('shift_u', gamma2, {'u.0': bc_fun})

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    pb = Problem('elasticity', equations=eqs, nls=nls, ls=ls)
    pb.save_regions_as_groups('regions')

    pb.time_update(ebcs=Conditions([fix_u, shift_u]))

    vec = pb.solve()
    print(nls_status)

    pb.save_state('linear_elasticity.vtk', vec)

    if options.show:
        view = Viewer('linear_elasticity.vtk')
        view(vector_mode='warp_norm',
             rel_scaling=2,
             is_scalar_bar=True,
             is_wireframe=True)
Exemplo n.º 28
0
def main():
    from sfepy import data_dir

    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('--young',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='young',
                      default=2000.0,
                      help=helps['young'])
    parser.add_option('--poisson',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='poisson',
                      default=0.4,
                      help=helps['poisson'])
    parser.add_option('--load',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='load',
                      default=-1000.0,
                      help=helps['load'])
    parser.add_option('--order',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='order',
                      default=1,
                      help=helps['order'])
    parser.add_option('-r',
                      '--refine',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='refine',
                      default=0,
                      help=helps['refine'])
    parser.add_option('-s',
                      '--show',
                      action="store_true",
                      dest='show',
                      default=False,
                      help=helps['show'])
    parser.add_option('-p',
                      '--probe',
                      action="store_true",
                      dest='probe',
                      default=False,
                      help=helps['probe'])
    options, args = parser.parse_args()

    assert_((0.0 < options.poisson < 0.5),
            "Poisson's ratio must be in ]0, 0.5[!")
    assert_((0 < options.order),
            'displacement approximation order must be at least 1!')

    output('using values:')
    output("  Young's modulus:", options.young)
    output("  Poisson's ratio:", options.poisson)
    output('  vertical load:', options.load)
    output('uniform mesh refinement level:', options.refine)

    # Build the problem definition.
    mesh = Mesh.from_file(data_dir + '/meshes/2d/its2D.mesh')
    domain = FEDomain('domain', mesh)

    if options.refine > 0:
        for ii in xrange(options.refine):
            output('refine %d...' % ii)
            domain = domain.refine()
            output('... %d nodes %d elements' %
                   (domain.shape.n_nod, domain.shape.n_el))

    omega = domain.create_region('Omega', 'all')
    left = domain.create_region('Left', 'vertices in x < 0.001', 'facet')
    bottom = domain.create_region('Bottom', 'vertices in y < 0.001', 'facet')
    top = domain.create_region('Top', 'vertex 2', 'vertex')

    field = Field.from_args('fu',
                            nm.float64,
                            'vector',
                            omega,
                            approx_order=options.order)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    D = stiffness_from_youngpoisson(2, options.young, options.poisson)

    asphalt = Material('Asphalt', D=D)
    load = Material('Load', values={'.val': [0.0, options.load]})

    integral = Integral('i', order=2 * options.order)
    integral0 = Integral('i', order=0)

    t1 = Term.new('dw_lin_elastic(Asphalt.D, v, u)',
                  integral,
                  omega,
                  Asphalt=asphalt,
                  v=v,
                  u=u)
    t2 = Term.new('dw_point_load(Load.val, v)', integral0, top, Load=load, v=v)
    eq = Equation('balance', t1 - t2)
    eqs = Equations([eq])

    xsym = EssentialBC('XSym', bottom, {'u.1': 0.0})
    ysym = EssentialBC('YSym', left, {'u.0': 0.0})

    ls = ScipyDirect({})

    nls_status = IndexedStruct()
    nls = Newton({}, lin_solver=ls, status=nls_status)

    pb = Problem('elasticity', equations=eqs, nls=nls, ls=ls)

    pb.time_update(ebcs=Conditions([xsym, ysym]))

    # Solve the problem.
    state = pb.solve()
    output(nls_status)

    # Postprocess the solution.
    out = state.create_output_dict()
    out = stress_strain(out, pb, state, extend=True)
    pb.save_state('its2D_interactive.vtk', out=out)

    gdata = geometry_data['2_3']
    nc = len(gdata.coors)

    integral_vn = Integral('ivn',
                           coors=gdata.coors,
                           weights=[gdata.volume / nc] * nc)

    nodal_stress(out, pb, state, integrals=Integrals([integral_vn]))

    if options.probe:
        # Probe the solution.
        probes, labels = gen_lines(pb)

        sfield = Field.from_args('sym_tensor',
                                 nm.float64,
                                 3,
                                 omega,
                                 approx_order=options.order - 1)
        stress = FieldVariable('stress',
                               'parameter',
                               sfield,
                               primary_var_name='(set-to-None)')
        strain = FieldVariable('strain',
                               'parameter',
                               sfield,
                               primary_var_name='(set-to-None)')

        cfield = Field.from_args('component',
                                 nm.float64,
                                 1,
                                 omega,
                                 approx_order=options.order - 1)
        component = FieldVariable('component',
                                  'parameter',
                                  cfield,
                                  primary_var_name='(set-to-None)')

        ev = pb.evaluate
        order = 2 * (options.order - 1)
        strain_qp = ev('ev_cauchy_strain.%d.Omega(u)' % order, mode='qp')
        stress_qp = ev('ev_cauchy_stress.%d.Omega(Asphalt.D, u)' % order,
                       mode='qp',
                       copy_materials=False)

        project_by_component(strain, strain_qp, component, order)
        project_by_component(stress, stress_qp, component, order)

        all_results = []
        for ii, probe in enumerate(probes):
            fig, results = probe_results(u, strain, stress, probe, labels[ii])

            fig.savefig('its2D_interactive_probe_%d.png' % ii)
            all_results.append(results)

        for ii, results in enumerate(all_results):
            output('probe %d:' % ii)
            output.level += 2
            for key, res in ordered_iteritems(results):
                output(key + ':')
                val = res[1]
                output('  min: %+.2e, mean: %+.2e, max: %+.2e' %
                       (val.min(), val.mean(), val.max()))
            output.level -= 2

    if options.show:
        # Show the solution. If the approximation order is greater than 1, the
        # extra DOFs are simply thrown away.
        from sfepy.postprocess.viewer import Viewer

        view = Viewer('its2D_interactive.vtk')
        view(vector_mode='warp_norm',
             rel_scaling=1,
             is_scalar_bar=True,
             is_wireframe=True)
def main(cli_args):
    dims = parse_argument_list(cli_args.dims, float)
    shape = parse_argument_list(cli_args.shape, int)
    centre = parse_argument_list(cli_args.centre, float)
    material_parameters = parse_argument_list(cli_args.material_parameters,
                                              float)
    order = cli_args.order

    ts_vals = cli_args.ts.split(',')
    ts = {
        't0': float(ts_vals[0]),
        't1': float(ts_vals[1]),
        'n_step': int(ts_vals[2])
    }

    do_plot = cli_args.plot

    ### Mesh and regions ###
    mesh = gen_block_mesh(dims, shape, centre, name='block', verbose=False)
    domain = FEDomain('domain', mesh)

    omega = domain.create_region('Omega', 'all')

    lbn, rtf = domain.get_mesh_bounding_box()
    box_regions = define_box_regions(3, lbn, rtf)
    regions = dict(
        [[r, domain.create_region(r, box_regions[r][0], box_regions[r][1])]
         for r in box_regions])

    ### Fields ###
    scalar_field = Field.from_args('fu',
                                   np.float64,
                                   'scalar',
                                   omega,
                                   approx_order=order - 1)
    vector_field = Field.from_args('fv',
                                   np.float64,
                                   'vector',
                                   omega,
                                   approx_order=order)

    u = FieldVariable('u', 'unknown', vector_field, history=1)
    v = FieldVariable('v', 'test', vector_field, primary_var_name='u')
    p = FieldVariable('p', 'unknown', scalar_field, history=1)
    q = FieldVariable('q', 'test', scalar_field, primary_var_name='p')

    ### Material ###
    c10, c01 = material_parameters
    m = Material(
        'm',
        mu=2 * c10,
        kappa=2 * c01,
    )

    ### Boundary conditions ###
    x_sym = EssentialBC('x_sym', regions['Left'], {'u.0': 0.0})
    y_sym = EssentialBC('y_sym', regions['Near'], {'u.1': 0.0})
    z_sym = EssentialBC('z_sym', regions['Bottom'], {'u.2': 0.0})
    disp_fun = Function('disp_fun', get_displacement)
    displacement = EssentialBC('displacement', regions['Right'],
                               {'u.0': disp_fun})
    ebcs = Conditions([x_sym, y_sym, z_sym, displacement])

    ### Terms and equations ###
    integral = Integral('i', order=2 * order)

    term_neohook = Term.new('dw_tl_he_neohook(m.mu, v, u)',
                            integral,
                            omega,
                            m=m,
                            v=v,
                            u=u)
    term_mooney = Term.new('dw_tl_he_mooney_rivlin(m.kappa, v, u)',
                           integral,
                           omega,
                           m=m,
                           v=v,
                           u=u)
    term_pressure = Term.new('dw_tl_bulk_pressure(v, u, p)',
                             integral,
                             omega,
                             v=v,
                             u=u,
                             p=p)

    term_volume_change = Term.new('dw_tl_volume(q, u)',
                                  integral,
                                  omega,
                                  q=q,
                                  u=u,
                                  term_mode='volume')
    term_volume = Term.new('dw_volume_integrate(q)', integral, omega, q=q)

    eq_balance = Equation('balance',
                          term_neohook + term_mooney + term_pressure)
    eq_volume = Equation('volume', term_volume_change - term_volume)
    equations = Equations([eq_balance, eq_volume])

    ### Solvers ###
    ls = ScipyDirect({})
    nls_status = IndexedStruct()
    nls = Newton({'i_max': 5}, lin_solver=ls, status=nls_status)

    ### Problem ###
    pb = Problem('hyper', equations=equations)
    pb.set_bcs(ebcs=ebcs)
    pb.set_ics(ics=Conditions([]))
    tss = SimpleTimeSteppingSolver(ts, nls=nls, context=pb)
    pb.set_solver(tss)

    ### Solution ###
    axial_stress = []
    axial_displacement = []

    def stress_strain_fun(*args, **kwargs):
        return stress_strain(*args,
                             order=order,
                             global_stress=axial_stress,
                             global_displacement=axial_displacement,
                             **kwargs)

    pb.solve(save_results=True, post_process_hook=stress_strain_fun)

    if do_plot:
        plot_graphs(material_parameters,
                    axial_stress,
                    axial_displacement,
                    undeformed_length=dims[0])
Exemplo n.º 30
0
def main():
    parser = OptionParser(usage=usage, version='%prog')
    parser.add_option('-d',
                      '--dims',
                      metavar='dims',
                      action='store',
                      dest='dims',
                      default='[1.0, 1.0]',
                      help=helps['dims'])
    parser.add_option('-c',
                      '--centre',
                      metavar='centre',
                      action='store',
                      dest='centre',
                      default='[0.0, 0.0]',
                      help=helps['centre'])
    parser.add_option('-s',
                      '--shape',
                      metavar='shape',
                      action='store',
                      dest='shape',
                      default='[11, 11]',
                      help=helps['shape'])
    parser.add_option('-b',
                      '--bc-kind',
                      metavar='kind',
                      action='store',
                      dest='bc_kind',
                      choices=['free', 'clamped'],
                      default='free',
                      help=helps['bc_kind'])
    parser.add_option('--young',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='young',
                      default=6.80e+10,
                      help=helps['young'])
    parser.add_option('--poisson',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='poisson',
                      default=0.36,
                      help=helps['poisson'])
    parser.add_option('--density',
                      metavar='float',
                      type=float,
                      action='store',
                      dest='density',
                      default=2700.0,
                      help=helps['density'])
    parser.add_option('--order',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='order',
                      default=1,
                      help=helps['order'])
    parser.add_option('-n',
                      '--n-eigs',
                      metavar='int',
                      type=int,
                      action='store',
                      dest='n_eigs',
                      default=6,
                      help=helps['order'])
    parser.add_option('',
                      '--show',
                      action="store_true",
                      dest='show',
                      default=False,
                      help=helps['show'])
    options, args = parser.parse_args()

    assert_((0.0 < options.poisson < 0.5),
            "Poisson's ratio must be in ]0, 0.5[!")
    assert_((0 < options.order),
            'displacement approximation order must be at least 1!')

    dims = nm.array(eval(options.dims), dtype=nm.float64)
    dim = len(dims)
    centre = nm.array(eval(options.centre), dtype=nm.float64)[:dim]
    shape = nm.array(eval(options.shape), dtype=nm.int32)[:dim]

    output('dimensions:', dims)
    output('centre:    ', centre)
    output('shape:     ', shape)
    output('using values:')
    output("  Young's modulus:", options.young)
    output("  Poisson's ratio:", options.poisson)
    output('  density:', options.density)

    # Build the problem definition.
    mesh = gen_block_mesh(dims, shape, centre, name='mesh')
    domain = FEDomain('domain', mesh)

    bbox = domain.get_mesh_bounding_box()
    min_y, max_y = bbox[:, 1]
    eps = 1e-8 * (max_y - min_y)
    omega = domain.create_region('Omega', 'all')
    bottom = domain.create_region('Bottom',
                                  'vertices in (y < %.10f)' % (min_y + eps),
                                  'facet')

    field = Field.from_args('fu',
                            nm.float64,
                            'vector',
                            omega,
                            approx_order=options.order)

    u = FieldVariable('u', 'unknown', field)
    v = FieldVariable('v', 'test', field, primary_var_name='u')

    mtx_d = stiffness_from_youngpoisson(dim, options.young, options.poisson)

    m = Material('m', D=mtx_d, rho=options.density)

    integral = Integral('i', order=2 * options.order)

    t1 = Term.new('dw_lin_elastic(m.D, v, u)', integral, omega, m=m, v=v, u=u)
    t2 = Term.new('dw_volume_dot(m.rho, v, u)', integral, omega, m=m, v=v, u=u)
    eq1 = Equation('stiffness', t1)
    eq2 = Equation('mass', t2)
    lhs_eqs = Equations([eq1, eq2])

    pb = Problem('modal', equations=lhs_eqs)

    if options.bc_kind == 'free':
        pb.time_update()
        n_rbm = dim * (dim + 1) / 2

    else:
        fixed_b = EssentialBC('FixedB', bottom, {'u.all': 0.0})
        pb.time_update(ebcs=Conditions([fixed_b]))
        n_rbm = 0

    pb.update_materials()

    # Assemble stiffness and mass matrices.
    mtx_k = eq1.evaluate(mode='weak', dw_mode='matrix', asm_obj=pb.mtx_a)
    mtx_m = mtx_k.copy()
    mtx_m.data[:] = 0.0
    mtx_m = eq2.evaluate(mode='weak', dw_mode='matrix', asm_obj=mtx_m)

    try:
        eigs, svecs = sla.eigsh(mtx_k,
                                k=options.n_eigs + n_rbm,
                                M=mtx_m,
                                which='SM',
                                tol=1e-5,
                                maxiter=10000)
    except sla.ArpackNoConvergence as ee:
        eigs = ee.eigenvalues
        svecs = ee.eigenvectors
        output('only %d eigenvalues converged!' % len(eigs))

    eigs = eigs[n_rbm:]
    svecs = svecs[:, n_rbm:]

    output('eigenvalues:', eigs)
    output('eigen-frequencies:', nm.sqrt(eigs))

    # Make full eigenvectors (add DOFs fixed by boundary conditions).
    variables = pb.get_variables()

    vecs = nm.empty((variables.di.ptr[-1], svecs.shape[1]), dtype=nm.float64)
    for ii in xrange(svecs.shape[1]):
        vecs[:, ii] = variables.make_full_vec(svecs[:, ii])

    # Save the eigenvectors.
    out = {}
    state = pb.create_state()
    for ii in xrange(eigs.shape[0]):
        state.set_full(vecs[:, ii])
        aux = state.create_output_dict()
        strain = pb.evaluate('ev_cauchy_strain.i.Omega(u)',
                             integrals=Integrals([integral]),
                             mode='el_avg',
                             verbose=False)
        out['u%03d' % ii] = aux.popitem()[1]
        out['strain%03d' % ii] = Struct(mode='cell', data=strain)

    pb.save_state('eigenshapes.vtk', out=out)
    pb.save_regions_as_groups('regions')

    if options.show:
        # Show the solution. If the approximation order is greater than 1, the
        # extra DOFs are simply thrown away.
        from sfepy.postprocess.viewer import Viewer
        from sfepy.postprocess.domain_specific import DomainSpecificPlot

        scaling = 0.05 * dims.max() / nm.abs(vecs).max()

        ds = {}
        for ii in xrange(eigs.shape[0]):
            pd = DomainSpecificPlot('plot_displacements', [
                'rel_scaling=%s' % scaling, 'color_kind="tensors"',
                'color_name="strain%03d"' % ii
            ])
            ds['u%03d' % ii] = pd

        view = Viewer('eigenshapes.vtk')
        view(domain_specific=ds,
             only_names=sorted(ds.keys()),
             is_scalar_bar=False,
             is_wireframe=True)