linear solvers

Solving incompressible elasticity has been quite challenging numerically. The conventional approach for handling incompressibility is the so-called penalty method. A volumetric energy term enters into the strain energy and penalizes the volumetric deformation. One straightforward issue is that the penalty parameter goes directly into the tangent matrix. The bigger the penalty parameter, the worse the condition number of the matrix. This is really a manifestation of the ill-posedness of theories based on the Helmholtz free energy, in my opinion [3].

I would like to share the following information to all the iMechanica users interested in using TAUCS a library of sparse linear solvers. TAUCS is among the most used libraries of sparse linear solvers and, to my knowledge, its closest equivalent library is SuperLU. For your reference, TAUCS is used in the commercial software Mathematica by Wolfram Research. Its source code can be downloaded from

http://www.tau.ac.il/~stoledo/taucs