Wave finite element-based superelements for forced response analysis of coupled systems via dynamic substructuring

The wave finite element (WFE) method is used for assessing the harmonic response of coupled mechanical systems that involve one-dimensional periodic structures and coupling elastic junctions. The periodic structures under concern are composed of complex heterogeneous substructures like those encountered in real engineering applications. A strategy is proposed that uses the concept of numerical wave modes to express the dynamic stiffness matrix (DSM), or the receptance matrix (RM), of each periodic structure. Also, the Craig-Bampton (CB) method is used to model each coupling junction by means of static modes and fixed-interface modes. An efficient WFE-based criterion is considered to select the junction modes that are of primary importance. The consideration of several periodic structures and coupling junctions is achieved through classic finite element (FE) assembly procedures, or domain decomposition techniques. Numerical experiments are carried out to highlight the relevance of the WFE-based DSM and RM approaches in terms of accuracy and computational savings, in comparison with the conventional FE and CB methods. The following test cases are considered: a 2D frame structure under plane stresses and a 3D aircraft fuselage-like structure involving stiffened cylindrical shells. Copyright (C) 2015 John Wiley & Sons, Ltd.