Hybrid finite element transfer matrix method and its parallel solution for fast calculation of large-scale structural eigenproblem

Abstract

Vibration characteristics play a fundamental role in structural analysis and dynamics design. The determination of vibration characteristics requires the solution of an eigenproblem. In this work, a novel parallel hybrid finite element (FE) transfer matrix method (TMM) is studied for a large-scale structural eigenproblem. The full structure is divided into some substructures, and the vibration characteristics of each substructure are calculated with their proper solution method (FE or TMM). Then by using the order-reduction transformation of the full structure based on an improved fixed interface modal synthesis, the reduced global equation of the full structure is obtained easily, and it can be used to solve the vibration characteristics of the full structure efficiently. To overcome the numerical instability of the ordinary transfer matrix technology in a large-scale structural analysis, the Riccati transform is also adopted. This hybrid method has good parallelism, and the corresponding parallel algorithms are presented. Finally, this method is applied to a vacuum vessel structure of the China fusion engineering test reactor, which has cyclic symmetry conditions. The simulation results demonstrate that this method has low computational cost and satisfactory accuracy.