Calculation of Composite Loss Factor Based on Iterative MSE Method

Abstract

Modal strain energy (MSE) method is a widely used approximation approach for parameter calculation of damped composite structures. In this paper, iterative MSE method is proposed to calculate the loss factor of composite damping structure by considering the frequency dependence of modulus and loss factor of viscoelastic damping materials. The proposed method is applied to free damping spline, free damping plate and constrain damping plate. The results show that: the proposed method obtains minimum relative errors of less than 5% and less than 20% for nature frequency and composite loss factor. The influence of different material parameters on the calculation results is also discussed. The error is smaller when using the storage modulus and loss factor measured by tensile mode as input parameter. The thickness of the sample to measure the dynamic material parameters has a great influence on accuracy. This work provides a way for the calculation of composite loss fator of damped composite structures with embedded viscoelastic layer.