def updStiffMatMS(self, elmLst, elmCompStiffMat):
self.K = mfem.ParBilinearForm(self.fespace)
lambVec = mfem.Vector(self.fespace.GetMesh().attributes.Max())
lambVec.Assign(self.lmbda)
lambVec[0] = lambVec[1]
lambda_func = mfem.PWConstCoefficient(lambVec)
muVec = mfem.Vector(self.fespace.GetMesh().attributes.Max())
muVec.Assign(self.mu)
muVec[0] = muVec[1]
mu_func = mfem.PWConstCoefficient(muVec)
self.K.AddDomainIntegrator(
mfem.ElasticityIntegrator(lambda_func, mu_func))
self.K.Assemble(0, elmLst, elmCompStiffMat, False, True)
self.Kmat = mfem.HypreParMatrix()
empty_tdof_list = intArray()
self.K.FormLinearSystem(empty_tdof_list, self.x_gfBdr, self.bx,
self.Kmat, self.vx.GetBlock(1), self.Bx, 1)
print("Number of unknowns: " + str(size))
print("Assembling")
# 8. Set up the parallel bilinear forms a(.,.) and m(.,.) on the finite
# element space corresponding to the linear elasticity integrator with
# piece-wise constants coefficient lambda and mu, a simple mass matrix
# needed on the right hand side of the generalized eigenvalue problem
# below. The boundary conditions are implemented by marking only boundary
# attribute 1 as essential. We use special values on the diagonal to
# shift the Dirichlet eigenvalues out of the computational range. After
# serial/parallel assembly we extract the corresponding parallel matrices
# A and M.
lamb = mfem.Vector(pmesh.attributes.Max())
lamb.Assign(1.0)
lamb[0] = lamb[1] * 50
lambda_func = mfem.PWConstCoefficient(lamb)
mu = mfem.Vector(pmesh.attributes.Max())
mu.Assign(1.0)
mu[0] = mu[1] * 50
mu_func = mfem.PWConstCoefficient(mu)
ess_bdr = mfem.intArray(pmesh.bdr_attributes.Max())
ess_bdr.Assign(0)
ess_bdr[0] = 1
a = mfem.ParBilinearForm(fespace)
a.AddDomainIntegrator(mfem.ElasticityIntegrator(lambda_func, mu_func))
if (myid == 0):
print("matrix ... ")
a.Assemble()
a.EliminateEssentialBCDiag(ess_bdr, 1.0)
# 9. Set up the parallel linear form b(.) which corresponds to the
# right-hand side of the FEM linear system. In this case, b_i equals the
# boundary integral of f*phi_i where f represents a "pull down" force on
# the Neumann part of the boundary and phi_i are the basis functions in
# the finite element fespace. The force is defined by the object f, which
# is a vector of Coefficient objects. The fact that f is non-zero on
# boundary attribute 2 is indicated by the use of piece-wise constants
# coefficient for its last component.
f = mfem.VectorArrayCoefficient(dim)
for i in range(dim - 1):
f.Set(i, mfem.ConstantCoefficient(0.0))
pull_force = mfem.Vector([0] * pmesh.bdr_attributes.Max())
pull_force[1] = -1.0e-2
f.Set(dim - 1, mfem.PWConstCoefficient(pull_force))
b = mfem.ParLinearForm(fespace)
b.AddBoundaryIntegrator(mfem.VectorBoundaryLFIntegrator(f))
print('r.h.s. ...')
b.Assemble()
# 10. Define the solution vector x as a parallel finite element grid
# function corresponding to fespace. Initialize x with initial guess of
# zero, which satisfies the boundary conditions.
x = mfem.GridFunction(fespace)
x.Assign(0.0)
# 11. Set up the parallel bilinear form a(.,.) on the finite element space
# corresponding to the linear elasticity integrator with piece-wise
# constants coefficient lambda and mu.
# boundary attribute 2 is indicated by the use of piece-wise constants
# coefficient for its last component.
print dim
f = mfem.VectorArrayCoefficient(dim)
c1 = mfem.ConstantCoefficient(0.0);
c2 = mfem.ConstantCoefficient(0.0);
c3 = mfem.ConstantCoefficient(0.0);
#for i in range(dim-1):
f.Set(0, c1)
f.Set(1, c2)
print [0]*pmesh.bdr_attributes.Max()
pull_force = mfem.Vector([0]*pmesh.bdr_attributes.Max())
pull_force[1] = -1.0e-2;
pull_force.Print()
c3 = mfem.PWConstCoefficient(pull_force)
f.Set(dim-1, c3)
b = mfem.ParLinearForm(fespace)
'''
b.AddBoundaryIntegrator(mfem.VectorBoundaryLFIntegrator(f))
print('r.h.s. ...')
b.Assemble()
# 10. Define the solution vector x as a parallel finite element grid
# function corresponding to fespace. Initialize x with initial guess of
# zero, which satisfies the boundary conditions.
x = mfem.GridFunction(fespace)
x.Assign(0.0)
print('here')
def __init__(self,
fespace,
lmbda=1.,
mu=1.,
rho=1.,
visc=0.0,
vess_tdof_list=None,
vess_bdr=None,
xess_tdof_list=None,
xess_bdr=None,
v_gfBdr=None,
x_gfBdr=None,
deform=None,
velo=None,
vx=None):
mfem.PyTimeDependentOperator.__init__(self, 2 * fespace.GetTrueVSize(),
0.0)
self.lmbda = lmbda
self.mu = mu
self.viscosity = visc
self.deform = deform
self.velo = velo
self.x_gfBdr = x_gfBdr
self.v_gfBdr = v_gfBdr
self.vx = vx
self.z = mfem.Vector(self.Height() / 2)
self.z.Assign(0.0)
self.w = mfem.Vector(self.Height() / 2)
self.w.Assign(0.0)
self.tmpVec = mfem.Vector(self.Height() / 2)
self.tmpVec.Assign(0.0)
self.fespace = fespace
self.xess_bdr = xess_bdr
self.vess_bdr = vess_bdr
self.xess_tdof_list = xess_tdof_list
self.vess_tdof_list = vess_tdof_list
# setting up linear form
cv = mfem.Vector(3)
cv.Assign(0.0)
#self.zero_coef = mfem.ConstantCoefficient(0.0)
self.zero_coef = mfem.VectorConstantCoefficient(cv)
self.bx = mfem.LinearForm(self.fespace)
self.bx.AddDomainIntegrator(
mfem.VectorBoundaryLFIntegrator(self.zero_coef))
self.bx.Assemble()
self.bv = mfem.LinearForm(self.fespace)
self.bv.AddDomainIntegrator(
mfem.VectorBoundaryLFIntegrator(self.zero_coef))
self.bv.Assemble()
self.Bx = mfem.Vector()
self.Bv = mfem.Vector()
# setting up bilinear forms
self.M = mfem.ParBilinearForm(self.fespace)
self.K = mfem.ParBilinearForm(self.fespace)
self.S = mfem.ParBilinearForm(self.fespace)
self.ro = mfem.ConstantCoefficient(rho)
self.M.AddDomainIntegrator(mfem.VectorMassIntegrator(self.ro))
self.M.Assemble(0)
self.M.EliminateEssentialBC(self.vess_bdr)
self.M.Finalize(0)
self.Mmat = self.M.ParallelAssemble()
self.M_solver = mfem.CGSolver(self.fespace.GetComm())
self.M_solver.iterative_mode = False
self.M_solver.SetRelTol(1e-8)
self.M_solver.SetAbsTol(0.0)
self.M_solver.SetMaxIter(30)
self.M_solver.SetPrintLevel(0)
self.M_prec = mfem.HypreSmoother()
self.M_prec.SetType(mfem.HypreSmoother.Jacobi)
self.M_solver.SetPreconditioner(self.M_prec)
self.M_solver.SetOperator(self.Mmat)
lambVec = mfem.Vector(self.fespace.GetMesh().attributes.Max())
print('Number of volume attributes : ' +
str(self.fespace.GetMesh().attributes.Max()))
lambVec.Assign(lmbda)
lambVec[0] = lambVec[1] * 1.0
lambda_func = mfem.PWConstCoefficient(lambVec)
muVec = mfem.Vector(self.fespace.GetMesh().attributes.Max())
muVec.Assign(mu)
muVec[0] = muVec[1] * 1.0
mu_func = mfem.PWConstCoefficient(muVec)
self.K.AddDomainIntegrator(
mfem.ElasticityIntegrator(lambda_func, mu_func))
self.K.Assemble(0)
# to set essential BC to zero value uncomment
#self.K.EliminateEssentialBC(self.xess_bdr)
#self.K.Finalize(0)
#self.Kmat = self.K.ParallelAssemble()
# to set essential BC to non-zero uncomment
self.Kmat = mfem.HypreParMatrix()
visc_coeff = mfem.ConstantCoefficient(visc)
self.S.AddDomainIntegrator(mfem.VectorDiffusionIntegrator(visc_coeff))
self.S.Assemble(0)
#self.S.EliminateEssentialBC(self.vess_bdr)
#self.S.Finalize(0)
#self.Smat = self.S.ParallelAssemble()
self.Smat = mfem.HypreParMatrix()
# VX solver for implicit time-stepping
self.VX_solver = mfem.CGSolver(self.fespace.GetComm())
self.VX_solver.iterative_mode = False
self.VX_solver.SetRelTol(1e-8)
self.VX_solver.SetAbsTol(0.0)
self.VX_solver.SetMaxIter(30)
self.VX_solver.SetPrintLevel(0)
self.VX_prec = mfem.HypreSmoother()
self.VX_prec.SetType(mfem.HypreSmoother.Jacobi)
self.VX_solver.SetPreconditioner(self.VX_prec)
# setting up operators
empty_tdof_list = intArray()
self.S.FormLinearSystem(empty_tdof_list, self.v_gfBdr, self.bv,
self.Smat, self.vx.GetBlock(0), self.Bv, 1)
self.K.FormLinearSystem(empty_tdof_list, self.x_gfBdr, self.bx,
self.Kmat, self.vx.GetBlock(1), self.Bx, 1)
