NUMERICAL STUDY OF AN INTRINSIC COMPONENT MODE SYNTHESIS METHOD

Component mode synthesis belongs to the class of Galerkin methods and it enables us to compute the normal modes of linearly elastic structures which can be divided into several substructures whose lowest eigenfrequencies and corresponding normal modes are known. Energy transfer between substructures is achieved thanks to the introduction in the Ritz procedure of mode shapes defined on the whole structure, usually called 'static modes' or 'constraint modes'. A new fixed interface method is presented in a continuous framework: it is based on a non-conventional choice of constraint modes tied to the normal modes of the Poincare-Steklov operator associated with the interface between the substructures. Error bounds are given in the case of three-dimensional elasticity. An efficient domain decomposition algorithm is presented in detail as well as various tests.