A Configuration-Driven Modal Optimization Method for Thin-Walled Structures Using a Surrogate-Assisted Evolutionary Algorithm with an Iterative Update Kriging Model

Abstract

A new configuration-driven modal optimization method is proposed in this work by utilizing the sensitivity of a thin-walled structure's modal characteristics to its configuration. Unlike the conventional technical roadmap in modal optimization of thin-walled structures, an adjustable configuration function is used to design undeformed configurations of thin-walled structures and to achieve the increase of certain natural frequencies of a thin-walled structure while other important non-designed natural frequencies minimally change. The weak form quadrature element method is used to solve modal characteristics of thin-walled structures with arbitrary undeformed configurations under natural coordinates. A surrogate-assisted evolutionary algorithm based on a novel iterative update Kriging model is adopted to enhance the optimization efficiency. As applications, modal crossings induced by undeformed configurations are studied in detail, and modal optimization problems of two kinds of thin-walled structures are given to assess its validity and effectiveness.

Keywords: modal optimization, weak form quadrature element method, Kriging model, Thin-walled structure