自動車ボディの振動解析効率化を目的とした局部振動除去による代表モード選定手法

抄録

In automotive development, vibration analysis using the finite element method is useful to predict and evaluate vibration problems such as noise, uncomfortable vibration and harshness. Although the finite element analysis (FEA) is used to reduce time and cost of the development, the analysis time has been increasing with improving the FEA and computers. It is because the detailed FEA provides more vibration modes. Analysts demand much time to evaluate and reduce the vibrations for all modes one by one. For this issue, it is helpful to select representative modes from the many modes to resolve the vibration problems. We propose a new method that selects the representative modes without empirical knowledge. The purpose of this study is to develop the selection method. The proposed method focuses on vibration shape of each mode. We classify it quantitatively into local part vibration and entire body vibration of the target structure. In this classification, we use Guyan reduction method to estimate the entire body vibration. Several modes whose entire body vibrations are dominant are selected as the representative modes. In this paper, we also applied the proposed method to a simple model that had ten modes in a frequency range of this analysis. In this demonstration, two modes were selected as the representative modes.