基于等效阻尼理论的金属橡胶弹性迟滞力学模型及实验研究

针对弹性多孔金属橡胶非线性迟滞特性力学行为,将迟滞恢复力-位移曲线分解为非线性单值曲线和椭圆,并将等效阻尼理论用于动态力学性能参数识别,从而建立了一种新型的适用于黏弹性阻尼材料的宏观唯象力学模型。采用不同相对密度的环形金属橡胶进行动态实验测试,以验证理论模型的准确性,结果表明该模型可将具有非线性特性的金属橡胶系统进行降阶处理,提高金属橡胶力学模型的预测效率,并能很好地描述金属橡胶的迟滞力学行为。另外,研究了在不同激励频率条件下金属橡胶的阻尼耗能特性。实验结果表明:在高频加载的条件下,黏性阻尼系数对动态加载频率不敏感,阻尼耗能与加载幅值之间呈线性正相关。基于等效阻尼理论的弹性迟滞力学模型具有一定的普适性,可进一步推广应用于类似弹性多孔材料的力学性能表征,为其工程应用提供理论基础。

Elasto-hysteresis model and experimental study of metal rubber based on equivalent damping theory

In order to describe the nonlinear hysteretic characteristics of elastic-porous metal rubber,the hysteretic restoring force-displacement curve is divided into a nonlinear single value curve and an ellipse.The corresponding parameter identification approach based on equivalent damping theory is proposed for the macroscopic phenomenal model,which can be used for the mechanical characterization of viscoelastic damping materials.Dynamic experimental tests of annular metal rubber with different relative densities are performed to verify the accuracy of the proposed theoretical model.The results reveal that this model can be used to reduce the nonlinear order of dynamic system and well describe the elasto-hysteresis behavior of metal rubber.In addition,the energy dissipation characteristics of metal rubber under different excitation frequencies are studied experimentally.The results indicate that the viscous damping ability is not susceptible to excitation frequency under the condition of high frequency.The energy dissipation of metal rubber exhibits a linear positive correlation to the loading amplitude.The proposed elasto-hysteresis model based on equivalent damping theory has good suitability and can be expanded for the mechanical characterization of similar elasto-porous materials,providing a theoretical basis for engineering applications.