Name

gf_mdbrick — General constructor for mdbrick object. Returns a getfem handle to the newly created object.

Calling Sequence

gf_mdbrick('constraint', mdbrick parent, string CTYPE [, int numfem])
gf_mdbrick('dirichlet', mdbrick parent, int BNUM, mesh_fem MFMULT, string CTYPE [, int numfem])
gf_mdbrick('dirichlet on normal component', mdbrick parent, int BNUM, mesh_fem MFMULT, string CTYPE [, int numfem])
gf_mdbrick('dirichlet on normal derivative', mdbrick parent, int BNUM, mesh_fem MFMULT, string CTYPE [, int numfem])
gf_mdbrick('generalized dirichlet', mdbrick parent, int BNUM [, int numfem])
gf_mdbrick('source term', mdbrick parent, [, int BNUM=-1[, int numfem]])
gf_mdbrick('normal source term', mdbrick parent, int BNUM [, int numfem])
gf_mdbrick('normal derivative source term', mdbrick parent, int BNUM [, int numfem])
gf_mdbrick('neumann KirchhoffLove source term', mdbrick parent, int BNUM [, int numfem])
gf_mdbrick('qu term', mdbrick parent, [, int BNUM [, int numfem]])
gf_mdbrick('mass matrix', mesh_im mim, mesh_fem mf_u [,'real'|'complex'])
gf_mdbrick('generic elliptic', mesh_im MIM, mesh_fem mfu [,'scalar'|'matrix'|'tensor'][,'real'|'complex'])
gf_mdbrick('helmholtz', mesh_im MIM, mesh_fem mfu [,'real'|'complex'])
gf_mdbrick('isotropic linearized elasticity', mesh_im MIM, mesh_fem mfu)
gf_mdbrick('linear incompressibility term', mdbrick parent, mesh_fem mf_p [, int numfem])
gf_mdbrick('nonlinear elasticity', mesh_im MIM, mesh_fem mfu, string lawname)
gf_mdbrick('nonlinear elasticity incompressibility term', mdbrick parent, mesh_fem mf_p [, int numfem])
gf_mdbrick('small deformations plasticity', mesh_im MIM, mesh_fem mfu, scalar THRESHOLD)
gf_mdbrick('bilaplacian', mesh_im MIM, mesh_fem mfu, ['Kirchhoff-Love'])
gf_mdbrick('isotropic_linearized_plate', mesh_im MIM, mesh_im MIMSUB, mesh_fem MF_UT, mesh_fem MF_U3, mesh_fem MF_THETA, scalar EPSILON)
gf_mdbrick('mixed_isotropic_linearized_plate', mesh_im MIM, mesh_fem MF_UT, mesh_fem MF_U3, mesh_fem MF_THETA, scalar EPSILON)
gf_mdbrick('plate_source_term', mdbrick parent, [, int BNUM=-1[, int numfem]])
gf_mdbrick('plate_simple_support', mdbrick parent, int BNUM, string CTYPE [, int numfem])
gf_mdbrick('plate_clamped_support', mdbrick parent, int BNUM, string CTYPE[, int numfem])
gf_mdbrick('plate_closing', mdbrick parent [, int numfem])
    

Description

Many of the bricks take a "numfem" optional parameter, which is the meshfem number in the stack of parent bricks (by default numfem=0, i.e. it refers to the first meshfem in the stack of bricks).

  • B = gf_mdbrick('constraint', MdBrick pb, string CTYPE[, int nfem]) Build a generic constraint brick. It may be useful in some situations, such as the Stokes problem where the pressure is defined modulo a constant. In such a situation, this brick can be used to add an additional constraint on the pressure value.

    CTYPE has to be chosen among 'augmented', 'penalized', and 'eliminated'. The constraint can be specified with gf_mdbrick_set(b,constraints'). Note that Dirichlet bricks (except the 'generalized Dirichlet' one) are also specializations of the 'constraint' brick.

  • B = gf_mdbrick('dirichlet', MdBrick pb, int bnum, MeshFem mf_m, string CTYPE[, int nfem]) Build a Dirichlet condition brick which impose the value of a field along a mesh boundary. The bnum parameter selects on which mesh region the Dirichlet condition is imposed. CTYPE has to be chosen among 'augmented', 'penalized', and 'eliminated'. The mf_m may generally be taken as the MeshFem of the unknown, but for 'augmented' Dirichlet conditions, you may have to respect the Inf-Sup condition and choose an adequate MeshFem.

  • B = gf_mdbrick('dirichlet on normal component', MdBrick pb, int bnum, MeshFem mf_m, string CTYPE[, int nfem]) Build a Dirichlet condition brick which imposes the value of the normal component of a vector field.

  • B = gf_mdbrick('dirichlet on normal derivative', MdBrick pb, int bnum, MeshFem mf_m, string CTYPE[, int nfem]) Build a Dirichlet condition brick which imposes the value of the normal derivative of the unknown.

  • B = gf_mdbrick('generalized dirichlet', MdBrick pb, int bnum[, int nfem]) This is the "old" Dirichlet brick of getfem. This brick can be used to impose general Dirichlet conditions h(x)u(x) = r(x), however it may have some issues with elaborated Fem's (such as Argyris, etc). It should be avoided when possible.

  • B = gf_mdbrick('source term', MdBrick pb[, int bnum=-1[, int nfem]]) Add a boundary or volumic source term ( \int B.v ). If bnum is omitted (or set to -1) , the brick adds a volumic source term on the whole mesh. For bnum >= 0, the source term is imposed on the mesh region bnum. Use gf_mdbrick_set(b,'param','source term',mf,B) to set the source term field. The source term is expected as a vector field of size Q (with Q = qdim).

  • B = gf_mdbrick('normal source term', MdBrick pb, int bnum[, int nfem]) Add a boundary source term ( \int (Bn).v ). The source term is imposed on the mesh region bnum (which of course is not allowed to be a volumic region, only boundary regions are allowed). Use gf_mdbrick_set(b,'param','source term',mf,B) to set the source term field. The source term B is expected as tensor field of size QxN (with Q = qdim, N = mesh dim).

    For example, if you consider an elasticity problem, this brick may be used to impose a force on the boundary with B as the stress tensor.

  • B = gf_mdbrick('normal derivative source term', MdBrick parent, int bnum[, int nfem]) Add a boundary source term ( \int (\partial_n B).v ). The source term is imposed on the mesh region bnum. Use gf_mdbrick_set(b,'param','source term',mf,B) to set the source term field, which is expected as a vector field of size Q (with Q = qdim).

  • B = gf_mdbrick('neumann KirchhoffLove source term', MdBrick pb, int bnum[, int nfem]) Add a boundary source term for neumann Kirchhoff-Love plate problems. Should be used with the Kirchhoff-Love flavour of the bilaplacian brick.

  • B = gf_mdbrick('qu term', MdBrick pb[, int bnum[, int nfem]]) Update the tangent matrix with a \int (Qu).v term. The Q(x) parameter is a matrix field of size qdim x qdim. An example of use is for the "iku" part of Robin boundary conditions \partial_n u + iku = ...

  • B = gf_mdbrick('mass matrix', MeshIm mim, MeshFem mf_u[, 'real'|'complex']) Build a mass-matrix brick.

  • B = gf_mdbrick('generic elliptic', MeshIm mim, MeshFem mfu[, 'scalar'|'matrix'|'tensor'][, 'real'|'complex']) Setup a generic elliptic problem.

    a(x)*grad(U).grad(V)

    The brick parameter a may be a scalar field, a matrix field, or a tensor field (default is scalar).

  • B = gf_mdbrick('helmholtz', MeshIm mim, MeshFem mfu[, 'real'|'complex']) Setup a Helmholtz problem. The brick has one parameter, 'wave_number'.

  • B = gf_mdbrick('isotropic linearized elasticity', MeshIm mim, MeshFem mfu) Setup a linear elasticity problem. The brick has two scalar parameter, 'lambda' and 'mu' (the Lame coefficients).

  • B = gf_mdbrick('linear incompressibility term', MdBrick pb, MeshFem mfp[, int nfem]) Add an incompressibily constraint (div u = 0).

  • B = gf_mdbrick('nonlinear elasticity', MeshIm mim, MeshFem mfu, string law) Setup a nonlinear elasticity (large deformations) problem.

    The material law can be chosen among:

    • 'SaintVenant Kirchhoff'<par> Linearized material law.

    • 'Mooney Rivlin' To be used with the nonlinear incompressibily term.

    • 'Ciarlet Geymonat'

  • B = gf_mdbrick('nonlinear elasticity incompressibility term', MdBrick pb, MeshFem mfp[, int nfem]) Add an incompressibily constraint to a large strain elasticity problem.

  • B = gf_mdbrick('small deformations plasticity', MeshIm mim, MeshFem mfu, scalar THRESHOLD) Setup a plasticity problem (with small deformations). The THRESHOLD parameter is the maximum value of the Von Mises stress before 'plastification' of the material.

  • B = gf_mdbrick('dynamic', MdBrick pb, scalar rho[, int numfem]) Dynamic brick. This brick is not ready.

  • B = gf_mdbrick('bilaplacian', MeshIm mim, MeshFem mfu[, 'Kirchhoff-Love']) Setup a bilaplacian problem. If the 'Kirchhoff-Love' option is specified, the Kirchhoff-Love plate model is used.

  • B = gf_mdbrick('navier stokes', MeshIm mim, MeshFem mfu, MeshFem mfp) Setup a Navier-Stokes problem (this brick is not ready, do not use it).

  • B = gf_mdbrick('isotropic_linearized_plate', MeshIm mim, MeshIm mims, MeshFem mfut, MeshFem mfu3, MeshFem mftheta, scalar eps) Setup a linear plate model brick. For moderately thick plates, using the Reissner-Mindlin model. eps is the plate thinkness, the MeshFem mfut and mfu3 are used respectively for the membrane displacement and the transverse displacement of the plate. The MeshFem mftheta is the rotation of the normal ("section rotations"). The second integration method mims can be chosen equal to mim, or different if you want to perform sub-integration on the transverse shear term (mitc4 projection). This brick has two parameters "lambda" and "mu" (the Lame coefficients)

  • B = gf_mdbrick('mixed_isotropic_linearized_plate', MeshIm mim, MeshFem mfut, MeshFem mfu3, MeshFem mftheta, scalar eps) Setup a mixed linear plate model brick. For thin plates, using Kirchhoff-Love model. For a non-mixed version, use the bilaplacian brick.

  • B = gf_mdbrick('plate_source_term', MdBrick pb[, int bnum=-1[, int nfem]]) Add a boundary or a volumic source term to a plate problem. This brick has two parameters: "B" is the displacement (ut and u3) source term, "M" is the moment source term (i.e. the source term on the rotation of the normal).

  • B = gf_mdbrick('plate_simple_support', MdBrick pb, int bnum, string CTYPE[, int nfem]) Add a "simple support" boundary condition to a plate problem. Homogeneous Dirichlet condition on the displacement, free rotation. CTYPE specifies how the constraint is enforced ('penalized', 'augmented' or 'eliminated').

  • B = gf_mdbrick('plate_clamped_support', MdBrick pb, int bnum, string CTYPE[, int nfem]) Add a "clamped support" boundary condition to a plate problem. Homogeneous Dirichlet condition on the displacement and on the rotation. CTYPE specifies how the constraint is enforced ('penalized', 'augmented' or 'eliminated').

  • B = gf_mdbrick('plate_closing', MdBrick pb[, int nfem]) Add a free edges condition for the mixed plate model brick. This brick is required when the mixed linearized plate brick is used. It must be inserted after all other boundary conditions (the reason is that the brick has to inspect all other boundary conditions to determine the number of disconnected boundary parts which are free edges).

See Also

gf_mdbrick_set, gf_mdbrick_get

Authors

Y. Collette