Optimum design of frame column subjected to axial crushing by statistical optimization method

Abstract

The authors proposed a new practical optimum design method (=statistical optimization method) that consists of two steps of an effectivity analysis (using a combination of the design of experiments and the structural analysis) and mathematical programming. The design of experiments is used to generate the approximate evaluation functions for the controlling behavior depending on the changes of design variables of the object structure, using finite element analysis (FEA). The evaluation functions can also be used as tools for directly estimating the behavior of the designed structure. A successive quadratic programming (SQP) method is employed to solve the optimization problem of the approximate evaluation functions. It is confirmed that the proposed method can be used in solving various problems. In this study, the authors applied the present method to the optimum design of a frame column subjected to axial crushing. This study deals with many complex behaviors such as large deformation, contact and material nonlinearities as well as impact behavior. However, this problem has been solved easily using the present method, and satisfactory results of the effectivity analysis and optimum design are obtained.