Vibration Reduction Design of Torpedo Engine Based on Modal Contribution Method

Abstract

Aiming at improving the structure of torpedo engine, the damping technology based on modal contribution method was proposed. Based on the results of the linear combination analysis of the modal participation factors, the vibration control method of the constrained damping layer was designed to control the dominant modes with large contribution. Firstly, the dynamic model of torpedo engine support structure is built, and the modal frequency, modal displacement and normalized modal stiffness are obtained. The dominant modes in the target frequency band are calculated, and the first 24 modes are analyzed. According to the mode shape of dominant mode, the constrained damping layer is designed for the engine. The optimized structure was verified by numerical simulation and the corresponding experimental results. The results showed that the damping technology based on modal participation factor can significantly reduce the vibration response of the engine support structure. This method creatively combines the dynamic design with the damping design, and obtains an effective damping method for engineering, especially for the military industry field with narrow space and strict weight requirements.