Vibration Reduction Method Effective for the Modal Group Formed with the Same Angle of Wave Vector on a Panel

Abstract

Panel vibrations that cause acoustic radiation often have high modal density. Therefore, vibration reduction design is required. For practical vibration analysis, FEA (Finite Element Analysis) is used for modal analysis. Then the designer has to control the eigenmode which needs measures, but often depends on experience and it is desirable to have a structural design method to control the mode. Therefore, this paper proposes a method of controlling eigenmodes as one of the method. The method is combining the concept of modal analysis and wave number vector. Firstly, it is shown that the vibration modes of thin plates have specific angles of wave number vectors. Secondly, phase closure principle is applied to the waves of specific angles to reduce vibration of thin plates. Finally, this research proposes a method to devise structural modification for vibration reduction using phase closure principle. In order to confirm the validity of the proposed method, it is shown by FEM of the simple supported rectangular. The result showed that the vibration of mode group of the aim is reducing.