Modal Analysis And Optimization Of Multi-branch And Multi-level Substructure Based On SiPESC Platform

With the rapid development of modern engineering techniques, the requirements of calculation and overall analysis are increasing for large-scale structures. A large and complex structure should satisfy the demands for the static and kinetic analysis under different working conditions. Furthermore, the different departments need to cooperate closely with each other to not only implement the interaction and transfer between computational model and data but data protection. The SIPESC software platform is developed by using new computer technology and software design methods on the basis of the experience in the past of CAE software development, and which inherit the research results from the independent research and development of finite element software JIFEX/DDJ/JIFEX. Finally, a new software integration platform for scientific computation is built gradually which provides some functions of mechanical analysis and convenient and practical tools and includes some unique algorithms.The main work of this thesis is depended on the SIPESC software platform. By using the high-precision multi-branch and multi-level substructure dynamic analysis algorithm and the visual workflow invocation of the SIPESC platform, an integrated analysis process of dynamic substructure is established, which further improves the computation efficiency and operability of the program. By applying the process, the overall models of rocket and aircraft are built and performed dynamic analysis. Furthermore, a script flow of optimization analysis is implemented based on the multi-branch and multi-level dynamic substructure analysis by further using the integration optimization analysis function of the platform---SIPESC.OPT1.0and the support for scripting language. This optimization analysis process can apply with the substructure stiffness scaling, mass scaling and geometric scaling, etc. to perform the integrated optimization analysis based on the multi-branch and multi-level dynamic substructure, and which can complete some tasks that some commercial software cannot offer. Finally, by the comparison the multi-branch and multi-level substructure method with the traditional dynamic sub-structural modal synthesis method (the super element method for MSC. Nastran) in both theory and numerical computation, the shortcomings of the modal synthesis method are pointed out and the advantages of multi-branch and multi-level substructure method are indicated.