Time-domain analysis for dynamic responses of non-classically damped composite structures

Abstract

A complex mode superposition method based on equivalent viscous damping model (CEV) is proposed for time-domain dynamic responses of non-classically damped composite structures. The damping matrix of hysteretic non-classically damped composite structures can be easily obtained and complex mode superposition method based on hysteretic damping model is directly realized in the physical space. However, hysteretic damping model is not causal, and is only applied in frequency-domain analysis. By the aid of constitutive model of Kelvin-Voigt model, viscous damping model which is equivalent to the hysteretic damping model is obtained based on single degree of freedom system. Combined with complex mode superposition method of hysteretic damping model and mathematical simplicity of equivalent viscous damping model, CEV can be realized. Structural vibration responses of shaking table test under random excitations are measured, which are compared with the corresponding calculation results using CEV and traditional complex mode superposition method based on viscous damping model (CR), respectively. The calculation results obtained by the two complex mode superposition methods are consistent with the test results. Compared with CR, the calculation results of CEV are unique, computationalefficiency of CEV is higher and the problem of choosing reasonable modes has been avoided.