Determination of Coupling Loss Factors Between Two Plates Joined at a Right Angle Using the Wave Approach

Abstract

Vibration transmission through two homogenous isotropic plates, joined at a right angle to each other, is studied using a wave approach in the audible frequency range. In this study, a generalized mathematical model is developed for the right-angled joint using a spring and dashpot model, which represents welded, riveted, and bolted joints. The energy transfer for the spring-dashpot model is determined in terms of transmission and reflection efficiencies of the aforementioned joints. The effect of variation of stiffness and damping of the joints on the transmission and reflection efficiencies is studied for variation in the coupled plate thickness and density ratio. The transmission efficiency is used to theoretically determine the coupling loss factor (CLF), which is an important parameter of statistical energy analysis (SEA) models. It is observed that with an increase in the mass of the second plate, it acts as a blocking mass to energy transfer. Experiments were performed on two mild steel plates connected using weld, rivet, and bolt joints to determine the CLFs for the joints and to verify the theoretical model. The CLFs determined from experiments and predicted using the wave approach were compared with those determined from the power injection method (PIM).