OOFEM

OOFEM is a free and open-source multi-physics finite element code with object oriented architecture. The aim of this project is to provide efficient and robust tool for FEM computations as well as to offer highly modular and extensible environment for development.

Main features

Solves various linear and nonlinear problems from structural, thermal and fluid mechanics.
Particularly includes many material models for nonlinear fracture mechanics of quasibrittle materials, such as concrete.
Efficient parallel processing support based on domain decomposition and message passing paradigms.
Direct as well as iterative solvers are available. Direct solvers include symmetric and unsymmetric skyline solver and sparse direct solver. Iterative solvers support many sparse storage formats and come with various preconditioners. Interfaces to third party linear and eigen value solver libraries are available, including IML, PETSc, SLEPc, and SPOOLES.
Support for Extended Finite Elements (XFEM) and iso-geometric analysis (IGA).

OOFEM is free, open source software, released under the GNU Lesser General Public License version 2.1 on any later version