关键词: 振动与波, 粘弹性, 模态应变能, 损耗因子, 固有频率

Abstract: Although viscoelastic structures have been widely used for vibration and noise reduction in the field of aerospace engineering, accurate calculation for dynamic parameters of viscoelastic structures remains difficult problem. Modal strain energy method and the corresponding modified methods have been always used for approximate calculations. On the basis of analysis of the priciples of existing modal strain energy methods and their correlations, a new modal strain energy method, whose correction factor varies with the amplitude of modal loss factor, is proposed for computing loss factor and natural frequency of viscoelastic structures. A four parameter prototype system, which is equivalent to beams and plates with constrained layer damping, and a new high damping spacecraft isolator are taken as example to verify accuracy of the proposed method by comparisons.

Key words: vibration and wave, viscoelastic, modal strain energy, loss factor, natural frequency