一种曲面-弹簧-滚子机构的非线性隔振器特性分析

设计了一种以曲面-弹簧-滚子机构为负刚度元件的非线性隔振系统,得到了系统零刚度条件;针对系统存在过载或欠载使用的情况,建立了谐波位移激励下系统非线性动力学方程,并应用谐波平衡法求解系统响应;分别分析了最小刚度为零和正刚度时,不同激励幅值、偏移量、阻尼比时的系统动态特性;最后通过实验验证了最小刚度为零时过载系统的动态特性。结果表明,所设计的隔振系统具有低频隔振效果,系统在过载使用时呈渐软或渐软-渐硬的刚度特性,具有很好的隔振性能;设计和使用中应当合理选择设置隔振器刚度系数、阻尼系数,并适当限制系统所受的最大激励幅值,从而保证系统具有更好的隔振性能。

Design and characteristics analysis of a nonlinear vibration isolator using a curved surface-spring-roller mechanism as negative stiffness element

Here,a nonlinear vibration isolation system was designed by taking a curved surface-spring-roller mechanism as a negative stiffness element to obtain the system’s zero stiffness condition.Aiming at cases of the system’s overload use and underload use,the system’s nonlinear dynamic equations were established under harmonic displacement excitations,and the system’s responses were solved by using the harmonic balance method(HBM).When the system’s minimum stiffness was zero or positive value,the dynamic characteristics of the system were analyzed under different excitation amplitudes,offset displacements and damping ratios.Finally,the dynamic characteristics of the overload system with the minimum stiffness of zero were verified through tests.The results showed that the designed vibration isolation system has the low-frequency vibration isolation effect,the system reveals gradually softening or gradually softening-gradually hardening stiffness characteristics when it is used under overload,and it has good vibration isolation performance;in design and application,the stiffness and damping coefficients of the isolator should be chosen reasonably,and the maximum excitation amplitude should be limited to ensure the system has better vibration isolation performance.