高层结构地震弹塑性全过程分析的数值子结构并行计算方法

Taking full advantage of the nonlinear localization for building structures under earthquakes, the numerical substructure method changed the original complex structural nonlinear analysis to the equivalent linear elastic analysis of a master structure, as well as nonlinear analyses of yield members in substructures separated from the master structure. However, there are some limitations in applications of nonlinear analysis of the super large-scale structure, due to the serial computation of the master structure. This paper presents a parallel numerical substructure method by the combination of the numerical substructure method with the traditional domain decomposition method. In the presented method, the whole structure can be divided into several elastic subdomains, of which the equivalent elastic analyses can be carried out in parallel. Nonlinear behaviors of yield members in each subdomain are computed in isolated substructures. In back substitution solutions of each subdomain, a reduced-order Newton-Raphson iterative scheme is proposed where nodal displacements associated with yielding member elements are regarded as basic unknown quantities, and consequently the size of matrix operation can be further reduced. A 15-story 3-bay plane steel frame structure under seismic loadings is analyzed, and simulation’s results show that the presented method is accurate and reliable. When applied to large-scale structures with local material nonlinearities, the dimensionality of matrix operations can be greatly reduced and the efficiency will be significantly improved. In addition, the large problem can be simplified into several small sub-problems, and therefore nonlinear analysis of much larger and more complex structures can be achieved.