A New Method for Dynamic Analysis of Spatial Lattice Structures Based on Mode Selection and Mode Construction Techniques

摘要

The traditional mode superposition method (MSM) is inefficient when applied to dynamic analyses of spatial lattice structures. The inapplicability and inefficiency of the MSM associated with spatial lattice structures are investigated and summarized in this paper. Based on mode selection and mode construction, a new modal set is constructed named Eigen- Loaddependent Ritz (Eigen-LDR) mode. Additionally, the computational procedure of the Eigen-LDR modes is presented. Furthermore, based on the constructed Eigen-LDR modes, a modified MSM, named the Eigen-LDR mode superposition method (EL-MSM), is proposed. Two typical spatial lattice structures, namely, a latticed shell and a spatial truss, are built as numerical examples. Seismic response analyses using the EL-MSM, including mode-superposition time history analysis and mode-superposition response spectrum analysis, are conducted simultaneously. The numerical results illustrate the accuracy, efficiency and generality of the method proposed in this paper.