def __init__(self, comm, tacs_comm, model, n_tacs_procs):
super(OneraPlate, self).__init__(comm, tacs_comm, model)
assembler = None
mat = None
if comm.Get_rank() < n_tacs_procs:
# Set the creator object
ndof = 6
creator = TACS.Creator(tacs_comm, ndof)
if tacs_comm.rank == 0:
# Create the elements
nx = 10
ny = 10
# Set the nodes
nnodes = (nx+1)*(ny+1)
nelems = nx*ny
nodes = np.arange(nnodes).reshape((nx+1, ny+1))
conn = []
for j in range(ny):
for i in range(nx):
# Append the node locations
conn.append([nodes[i, j],
nodes[i+1, j],
nodes[i, j+1],
nodes[i+1, j+1]])
# Set the node pointers
conn = np.array(conn, dtype=np.intc).flatten()
ptr = np.arange(0, 4*nelems+1, 4, dtype=np.intc)
elem_ids = np.zeros(nelems, dtype=np.intc)
creator.setGlobalConnectivity(nnodes, ptr, conn, elem_ids)
# Set the boundary conditions - fixed on the root
bcnodes = np.array(nodes[:, 0], dtype=np.intc)
creator.setBoundaryConditions(bcnodes)
root_chord = 0.8
semi_span = 1.2
taper_ratio = 0.56
sweep = 26.7 # degrees
# Set the node locations
Xpts = np.zeros(3*nnodes)
x = np.linspace(0, 1, nx+1)
y = np.linspace(0, 1, ny+1)
for j in range(ny+1):
for i in range(nx+1):
c = root_chord*(1.0 - y[j]) + root_chord*taper_ratio*y[j]
xoff = 0.25*root_chord + semi_span*y[j]*np.tan(sweep*np.pi/180.0)
Xpts[3*nodes[i,j]] = xoff + c*(x[i] - 0.25)
Xpts[3*nodes[i,j]+1] = semi_span*y[j]
# Set the node locations
creator.setNodes(Xpts)
# Set the material properties
props = constitutive.MaterialProperties(rho=2570.0, E=70e9, nu=0.3, ys=350e6)
# Set constitutive properties
t = 0.025
tnum = 0
maxt = 0.015
mint = 0.015
con = constitutive.IsoShellConstitutive(props, t=t, tNum=tnum)
# Create a transformation object
transform = elements.ShellNaturalTransform()
# Create the element object
element = elements.Quad4Shell(transform, con)
# Set the elements
elems = [ element ]
creator.setElements(elems)
# Create TACS Assembler object from the mesh loader
assembler = creator.createTACS()
# Create distributed matrix
mat = assembler.createSchurMat() # stiffness matrix
self._initialize_variables(assembler, mat)
self.initialize(model.scenarios[0], model.bodies)
return
for i in range(nquads):
t = quads[i, 2]
quads[i, 2] = quads[i, 3]
quads[i, 3] = t
# Flatten the arrays
pts = pts.flatten()
quads = (quads.flatten()).astype(np.intc)
# Set the pointer to the connectivity array
ptr = np.arange(0, 4 * nquads + 1, 4, dtype=np.intc)
ids = np.arange(0, nquads, dtype=np.intc)
# Create the tacs creator
vars_per_node = 6
creator = TACS.Creator(comm, vars_per_node)
creator.setGlobalConnectivity(npts, ptr, quads, ids)
creator.setNodes(pts)
# Set constitutive properties
rho = 2500.0 # density, kg/m^3
E = 70e9 # elastic modulus, Pa
nu = 0.3 # poisson's ratio
kcorr = 5.0 / 6.0 # shear correction factor
ys = 350e6 # yield stress, Pa
min_thickness = 0.002
max_thickness = 0.20
thickness = 0.02
stiff = constitutive.isoFSDT(rho, E, nu, kcorr, ys, thickness, 0,
min_thickness, max_thickness)
# Compute the stresses
s = np.zeros(e.shape)
s[0] = self.D * (e[0] + self.nu * e[1])
s[1] = self.D * (e[1] + self.nu * e[0])
s[2] = self.G * e[2]
# Compute the valure of the failure function
fval = (s[0]**2 + s[1]**2 - s[0] * s[1] + 3 * s[2]**2) / self.ys**2
return fval
# Allocate the TACS creator
comm = MPI.COMM_WORLD
creator = TACS.Creator(comm, 2)
# Create the stiffness object
rho = 2570.0
E = 70e9
nu = 0.3
ys = 350e6
# stiff = constitutive.PlaneStress(rho, E, nu)
stiff = PS(rho, E, nu, ys)
# Create the elements
elem_order = 2
elem = elements.PlaneTri6(stiff)
if comm.rank == 0:
def create_structure(comm,
props,
xpts,
conn,
bcs,
aux,
m_fixed,
r0=4,
min_mat_fraction=-1.0,
bctypes=None):
'''
Create a structure with the speicified number of nodes along the
x/y directions, respectively.
'''
# Set the number of design variables
nnodes = len(xpts)
nelems = len(conn)
nmats = props.getNumMaterials()
num_design_vars = (nmats + 1) * nelems
# Create the TACS creator object
creator = TACS.Creator(comm, 2)
# Set up the mesh on the root processor
if comm.rank == 0:
# Set the node pointers
ptr = np.arange(0, 4 * nelems + 1, 4, dtype=np.intc)
elem_ids = np.arange(nelems, dtype=np.intc)
creator.setGlobalConnectivity(nnodes, ptr, conn.flatten(), elem_ids)
# Set up the boundary conditions
bcnodes = np.array(bcs, dtype=np.intc)
# Set the boundary condition variables
if bctypes is None:
nbcs = 2 * bcnodes.shape[0]
bcvars = np.zeros(nbcs, dtype=np.intc)
bcvars[:nbcs:2] = 0
bcvars[1:nbcs:2] = 1
# Set the boundary condition pointers
bcptr = np.arange(0, nbcs + 1, 2, dtype=np.intc)
else:
bcvars = []
bcptr = [0]
for btype in bctypes:
if btype & 1:
bcvars.append(0)
if btype & 2:
bcvars.append(1)
bcptr.append(len(bcvars))
bcvars = np.array(bcvars, dtype=np.intc)
bcptr = np.array(bcptr, dtype=np.intc)
creator.setBoundaryConditions(bcnodes, bcptr, bcvars)
# Set the node locations
creator.setNodes(xpts.flatten())
# Create the filter and the elements for each point
elems = []
const = []
xcentroid = np.zeros((nelems, 3))
for i in range(nelems):
xcentroid[i] = 0.25 * (xpts[conn[i, 0]] + xpts[conn[i, 1]] +
xpts[conn[i, 2]] + xpts[conn[i, 3]])
# Find the closest points
locator = multitopo.Locator(xcentroid)
max_points = 15
for i in range(nelems):
# Get the closest points to the centroid of this element
nodes, dist = locator.closest(xcentroid[i], max_points)
index = 0
while index < max_points and dist[index] < r0:
index += 1
# Create the filter weights
nodes = nodes[:index]
weights = ((r0 - dist[:index]) / r0)**2
weights = weights / np.sum(weights)
# Create the plane stress object
ps = multitopo.MultiTopo(props, nodes, weights)
const.append(ps)
elems.append(elements.PlaneQuad(2, ps))
# Set the elements
creator.setElements(elems)
# Create the tacs assembler object
tacs = creator.createTACS()
# Retrieve the element partition
if comm.rank == 0:
partition = creator.getElementPartition()
# Broadcast the partition
comm.bcast(partition, root=0)
else:
partition = comm.bcast(root=0)
# Add the auxiliary element class to TACS
tacs.setAuxElements(aux)
# Create the analysis object
analysis = TACSAnalysis(comm,
props,
tacs,
const,
nmats,
conn=conn,
xpts=xpts,
m_fixed=m_fixed,
min_mat_fraction=min_mat_fraction)
return analysis
