考虑基底层阻尼的自由阻尼结构损耗因子修正公式

摘要

针对基底层阻尼不可忽略的自由阻尼结构，考虑基底层的拉伸变形，根据变形能理论和复刚度理论分别推导得到修正的损耗因子公式。而后利用ANSYS软件建立自由阻尼矩形板的实体模型并进行谐响应分析，分别通过变形能法和输入率法得到结构损耗因子的数值解。仿真对比表明，变形能法和复刚度法两种损耗因子修正公式的计算结果相吻合，结构损耗因子的两种有限元数值解均与修正公式的解析解相一致。研究表明，损耗因子修正公式是正确的，可用于一般基底层的自由阻尼类结构的损耗因子计算。%For unconstrained damped (UD)structures whose base layer’s damping can not be neglected,revised loss factor formulas were derived based on the strain energy method (SEM)and complex stiffness method (CSM)with the base layer’s shear deformation considered.Solid models of UD rectangle plates were developed with ANSYS and based on the model,a harmonic analysis was done.The numerical solutions of structural loss factors were obtained by using the input power method and SEM.The simulation results show that analytical solutions by SEM and CSM are coincident and are in good agreement with the numerical solutions by two FEA methods.The research demonstrates the revised loss factor formulas are correct and benefitial to improve the prediction of UD structures’ damping characteristics.