Design of Flexible Bodies in Multibody Dynamic Systems Using Equivalent Static Load Method

Abstract

Flexible multibody dynamic systems is the multibody system whose linkages are deformable bodies. Because the systems are time dependent, the analysis type is transient analysis. It is not straightforward to perform tra nsient response optimization due to a few troubles such as sensitivity analysis, time depende nt constraints, etc. Recently, Equivalent Static Load method has been proposed to handle transient response optimization of structures. Consequently, it has been shown that E quivalent Static Load method can be applied to optimization of flexible multibody dynam ic systems. Equivalent Static Load method is implemented in OptiStruct. In this paper , Several flexible multibody dynamic systems are taken for performance comparison between Equivalent Static Load and Response Surface Method. OptiSturct and HyperStudy are utilized for ESL method and RSM, respectively. In many cases, the results obta ined by Equivalent Static Load method are better than those obtained by Response Surface Method. Especially, the comparison shows that when the number of design variables is l arge, Equivalent Static Load method is superior to Response Surface Method. One of examples in this paper demonstrates a flexible multibody optimization problem with 30 design variables. This paper also demonstrates ESL method can be combined with free-size optimization, free-shape optimization, and topography optimization.