计入静位移作用的粘弹阻尼器双线性迟滞模型

在传统的粘弹阻尼器双线性迟滞模型基础上,为了便于参数识别,将滑移迟滞恢复力等效成黏性阻尼力与分段线性弹性力的联合作用,引入指数衰减函数表征弹性力及阻尼力随激振幅值的变化规律,并导出了带静位移的粘弹阻尼器复模量计算模型。提出一种结合复模量及迟滞回线进行参数识别的方法,并通过实例验证了改进模型的准确性及参数识别法的有效性。分析了静位移对迟滞回线及复模量的影响,结果表明:静位移的变化使得迟滞回线沿弹性力曲线移动,并由于非线性刚度的影响,迟滞回线的形状也发生了变化;在模型采用奇次弹性力和线性黏性阻尼力的条件下,储能模量随着静位移的变化成偶次函数的趋势变化,而耗能模量则不受静位移的影响;静位移对储能模量和耗能模量的影响源于粘弹阻尼器刚度和阻尼关于位移的非线性特性。

Bilinear Hysteresis Model of Elastomeric Damper with Static Shift

Based on traditional bilinear hysteresis model of elastomeric damper, slide hysteresis force can be equivalent to viscous damping force and piecewise linear elastic force for identifying parameters easily, and decaying exponential function is introduced to indicate the changing rule of elastic force and damping force with excitation amplitude. Complex modulus model is established for elastomeric damper with static shift, and a parameter identification method on the basis of complex modulus and hysteresis loop is presented. Then the accuracy of improved model and effectiveness of parameter identification method are all validated by numerical examples. The influence of static shift on hysteresis loop and complex modulus are analyzed. The results show that:hysteresis loop moves along the elastic force curve with static shift changing, and the form of hysteresis loop changes on account of nonlinear stiffness. When the model uses odd order elastic force and linear damping force, storage modulus appears even order function changing with static shift, and loss modulus is invariant. The influence of static shift on storage modulus and loss modulus is attributed to nonlinear stiffness and damping with displacement.