This work presents a modular approach well adapted for the analysis of complex situations of three-dimensional assemblies of elastic structures. The CONTRAST approach takes easely into account local nonlinearities due to contact or to technological elements (joints, hardly stressed bolts, ...). It is based on a decomposition of the assembly into subtructures and interfaces that are mechanical entities with their own equations and own unknowns. Interfaces play a major role by simply modeling local nonlinearities. The iterative resolution scheme is based on the Large Time Increment (LATIN) method. The CONTRAST approach is thus based on a strategy and a formulation that are both parallel. This intrinsic parallelism allows a great flexibility and a great modularity in the definition of the problem and allows the use of incompatible meshes on the interfaces. It also allows a great reduction of the computational costs with respect to the classical finite element method. Comparisons with industrial FE codes validate the treatment of friction and contact problems. Some industrial examples present the capabilities of the approach and his behaviour on a parallel computer.
