Time-domain substructure synthesis with hybrid rigid and nonlinear-elastic joints

The development of a new impulse response function (IRF) coupling analysis method, the hybrid nonlinear joint description method (HNJDM), was demonstrated and compared with the conventional impulse-based substructuring (IBS) method. The HNJDM is an extension of the IBS method, and it is able to consider purely rigid, purely nonlinear-elastic or even hybrid rigid and nonlinear-elastic connections between substructures. The joints are modeled and assembled into the system in an explicitly mathematical form. As a result, if the IRFs of the substructures are available via the numerical calculation or the physical measurement, it is unnecessary to establish the finite element models for the joints or build the equivalent model of the joint by using the dynamic testing. The HNJDM possesses high efficiency; the variation of the joint parameters does not lead to the reanalysis of the substructures. So it also provides an effective solution strategy for other technique fields like design optimization, model updating, and parameter identification. Finally, it can reduce the size of the effective tangent stiffness matrix in the Newton iterative procedure to the number of the joint coordinates, which is much smaller than the size of the whole system dimension.