弾塑性時刻歴応答を考慮した鋼構造建物の設計問題のための部分的感度情報を用いた最適設計法

Abstract

Design problems with transient dynamic elasto-plastic analysis exhibit noisy and nonsmooth responses with respect to their design parameters. This leads to situations in which some derivatives may be inaccurate and/or computationally expensive to obtain, whereas others may be readily available. For such problems, derivative-free approaches seem to be more appropriate than conventional derivative-based methods because some derivatives do not exist and/or are noisy. High cost for derivative evaluation is also frequently encountered in real-world design problems. This paper presents a new optimization method which is essentially derivative-free. However, the proposed method can reflect the geometry of some smooth and inexpensive response functions. This enables enhancement of the derivative-free method by including the derivative information on some constraints. The approach can be interpreted as a practical compromise between derivative-based and derivative-free methods. Furthermore, the proposed method can also be interpreted as a meta-modeling framework, ensuring global convergence in nonsmooth optimization. The efficiency of the proposed method is studied through a numerical example of steel frame with transient analysis. The numerical result illustrates that the proposed method finds better solutions than typical derivative-based and derivative-free methods and shows reasonable convergence in all cases.