Fast dynamic performance optimization of complicated beam-type structures based on two new reduced physical models

Abstract

In this article, two new model reduction methods for fast dynamic performance optimization of complicated beam-type structures are presented. In the new model reduction methods the projection of structural nodal degrees of freedom is carried out using the localized base vectors, which are obtained by physical hypothesis. The first new model reduction method constructs the base vectors based on the assumption of block-wise rigid body motion modified by minimizing the displacement error measured in strain energy. The second new model reduction method is based on the plane cross-section assumption, and the crosssectional warp deformation is also taken into consideration. Then, two reduced optimization models based on each method and design variable decomposition are formulated and solved. Both reduced optimization models are compared with the response surface method-based structural optimization approach. Some examples are presented to demonstrate the feasibility and effectiveness of the proposed methods.

Beam Approximation for Dynamic Analysis of Launch Vehicles Modelled as Stiffened Cylindrical Shells

“…The accuracy is dependent on the understanding of the mechanical properties of the typical unit cells. The method proposed by Zheng et al [Wang, Cheng and Li (2013)] divided a FE model of a stiffened cylindrical shell into several regions and assumed that each region was a rigid body. Then, a transformation relationship between the local motion and the global motion was constructed to reduce the FE model.…”