Contents     Functions     Index     Previous Next     PDF

7.6  FEM model structure



Finite element simulations are best handled using standard data structures supported by OpenFEM. The two main data structures are model which contains information needed to specify a FEM problem, and DEF which stores a solution.

Finite element models are described by their topology (nodes, elements and possibly coordinate systems), their properties (material and element). Computations performed with a model are further characterized by a case as illustrated in section 5.3.3 and detailed in section 7.7.

Data structures describing finite element models have the following standardized fields, where only nodes and elements are always needed.


.bas local coordinate system definitions
.cta sensor observation matrix. Used by fe_sens.
.copt solver options. For use by upcom. This field is likely to disappear in favor of defaults in sdtdef.
.DOF DOF definition vector for the matrices of the model. Boundary conditions can be imposed using cases.
.Elt elements. This field is mandatory.
.file Storage file name. Used by upcom.
.il element property description matrix. Can also be stored as 'pro' entries in the Stack.
.K{i} cell array of constant matrices for description of model as a linear combination. Indices i match definitions in .Opt(2,:) and .Opt(3,:). Should be associated with a .Klab field giving a string definition of each matrix. See details in the fe_super reference.
.mind element matrix indices. Used by upcom.
.Node nodes. This field is mandatory.
.Opt options characterizing models that are to be used as superelements
.pl material property description matrix. Can also be stored as 'mat' entries in the Stack.
.Patch Patch face matrix. See fe_super.
.Stack A cell array containing optional properties further characterizing a finite element model. See stack_get for how to handle the stack and the next section for a list of standardized entries.
 
.TR projection matrix. See fe_super.
.unit main model unit system (see fe_mat convert for a list of supported unit systems and the associated two letter codes).
.wd working directory

Obsolete fields are .Ref Generic coordinate transformation specification, .tdof test DOF field (now in SensDof entries).

©1991-2007 by SDTools
Previous Up Next