Optimization method of damping material layout with mode sensitivity omitted

Abstract

Damping materials are used everywhere to reduce the vibration level. On the vehicle, weight reduction and high damping effect is required to reduce environmental impact. Many studies have been conducted to find a topological optimal distribution with high damping effect with a small amount of damping material. However, many methods require finite element analysis many times due to eigenmode sensitivity. In addition, if there is a problem with the optimal shape, it is necessary to use a filter or change the penalty parameter and perform optimization again. This paper proposes a method to linearize the optimization problem, assuming that the distribution of damping material does not affect the eigenmode in order to reduce the number of finite element analysis. Several numerical examples are provided to show effectiveness of proposed method. As a result of verification, the optimal distribution and loss factor of proposed method and conventional method are almost the same for a large-scale finite element analysis model. Moreover, this paper shows that the assumption approximately holds by using the modal assurance criterion. As long as the assumption holds, by using the proposed method, a dramatic improvement in time efficiency when performing optimization with difference conditions many times can be expected.