The following capabilities are available in the MODULEF library:
Automatic generation and modification of two- and three-dimensional meshes.
Specification of material characteristics or external forces by sub-domain or boundary section.
Choice of type of finite element method, for example, conforming, non-conforming, hybrid, or mixed. For
non-conforming methods the flow and stresses can be computed along with the temperature or displacement,
or separately.
The finite element library contains about 36 elements for thermal analysis:
two- and three-dimensional, and axisymmetric elements,
and about 61 elements for elasticity for isotropic and anisotropic materials:
two-dimensional plane stress or plane strain elements,
three-dimensional elements,
axisymmetric elements,
plate and shell elements, and
elements for hyper-elastic compressible and incompressible materials in non-linear elasticity.
and 4 elements for magnetism and 2 elements for piezoelectric materials.
Linear systems can be solved using direct or iterative methods:
Direct methods: Cholesky, Crout or Gauss factorisation is used depending on the nature of the system matrix.
The matrix storing technique is a
skyline storage in main or secondary memory.
Iterative methods: Symmetric or non-symmetric linear systems are solved iteratively using a choice of conjugate gradient methods
with or without preconditioning, or relaxation. Compact storage is used to store the
matrices (only non-zero entries are stored).
Solution methods for eigenproblems include inverse iteration, subspace iteration, Lanczos and QR methods.
The solution of time-dependent thermal problems and dynamic problems by:
classical multi-step,
Gear multistep predictor-corrector,
3rd - order semi implicit Runga-Kutta.
The step-size is selected automatically in the last two methods, as well as the order of the scheme for the
Gear method.
Non-linear elasticity:
the solution of unilateral contact problems with or without friction by iterative algorithms,
the calculation of stresses in two- or three-dimensional elastoplasticity and the visualisation of plastic
zones,
the calculation of large deformations of compressible or incompressible hyperelastic
solids (two- or three-dimensional, or axisymmetric).
Solution of variational inequalities subject to bounded constraints by relaxation and complementarity.
Solution of the Dirichlet problem for a biharmonic operator by a mixed finite element
method of order 1 or 2.
Calculation of velocities and pressure of a viscous incompressible fluid (Navier-Stokes equations).
The computation of homogenised coefficients of composite structures.
Decomposition of domains.
Calculation of stresses and interpretation of results, for example:
calculation of error norms,
calculation of the sum of the element residues,
gluing together of two adjacent meshes and their corresponding solutions, etc.
Several modules are available for the display of results, interactively or in batch, for example to plot
two- or three-dimensional meshes, deformations, stresses, isovalues, velocities and streamlines in fluid
mechanics, etc.
