Mode Classification Method Considering the Characteristics of Panel Structures

Abstract

Computer simulations using the combination of finite element method (FEM) and modal analysis are now useful methods for vibration prediction. However, when it comes to detailed models of large-scale structures, it takes time to evaluate and reduce each characteristic mode one by one. Especially, coupled modes that consist of global and local deformations require careful treatment for reducing vibrations. In order to reduce vibrations of coupled modes, it is essential to reinforce respective parts that relate to each deformation with proper balance. This is because applying incorrect reinforcement contributes to vibration increase. The purpose of this study is to classify each characteristic mode into groups based on its dynamic behavior and approaches for vibration reduction. It is effective for panel structures to focus on global and local deformations of each mode. Based on deformation shapes and their correlations, the characteristic modes of a panel structure are divided into three groups: global modes, local modes and coupled modes. By means of the classification, effective vibration reduction approaches for each mode group is presented. The behavior of coupled modes’ vibration increases and decreases caused by different reinforcements is also demonstrated. Furthermore,