Reduction of noise and vibration by sensitivity analysis of stiffness modification with strain measurement

Abstract

This paper examines the stiffness sensitivity analysis for reduction of the sound radiation from a mechanical structure. In order to decrease the radiated sound from the structure, vibration with respect to out-of-plane needs to be decreased. Therefore, the addition of bending stiffness is considered to decrease the out-of-plane vibration. This paper formulates the stiffness sensitivity analysis by using the strain measurement. The proposed method is applied to the mechanical structure: a rear frame of the motor cycle, as an example of the industrial product with reducing noise required. The response evaluation point is set on the frame structure that is a candidate location of noise radiation. The sensitivity analysis is applied in order to reduce the frequency response of the evaluation point within a certain frequency band. As a result, the reduction of the response is attained by adding the stiffening plate to a certain location on the frame. The location is effectively determined by analyzing the sensitivity with respect to stiffness and mass changes.