考虑间隙的弹塑性断路器弹簧操动机构动力学特性研究

Dynamic Characteristic Analysis on the Elastoplastic Spring Operating Mechanism of High Voltage Circuit Breaker with Clearance

基于碰撞理论及Johnson-Cook模型,建立了含间隙某型高压断路器弹簧操动机构有限元弹塑性动力学模型,研究了机械系统中分、合闸过程大功率脉冲诱发的复杂宽带非线性动力学特性,探讨了销轴及轴套挤压变形及失效破坏的产生机理,同时采用动力显示积分法、通过试验测试及能量平衡理论验证了模型的准确性。研究表明:间隙会导致销轴和轴套发生接触碰撞,弹塑性会导致碰撞过程中弹簧操动机构的构件发生挤压变形,运动副间隙和构件弹塑性共同分配操动机构输入能量,需综合考虑才能得到较真实的机构动力学响应;适当增加间隙会将弹簧操动机构瞬间的部分驱动能量转换成铰接处接触碰撞的能量,由此降低了构件的弹性变形,缓冲了机构冲击振动。该结果可为机械操动机构研究提供参考。

An elastoplastic finite element dynamic model for the spring operating mechanism of a high voltage circuit breaker with clearance was established based on the collision theory and Johnson-Cook model.The wide-band nonlinear dynamic characteristics due to the high power pulse in mechanical system were studied.And the mechanism of extrusion deformation and structural failure of pin and sleeve was analyzed.Moreover,the dynamic explicit integration method was used to verify the model,and the accuracy of the model was proved by experimental tests and energy equilibrium theory.Simulation results indicate that the clearance causes the inner contact and impact between the pin and sleeve,and the elastoplastic behavior leads to the extrusion deformation of the components.The input energy of the mechanism is allocated by the clearance and elastoplastic behavior.These factors must be taken into account for obtaining more accurate dynamic responses.The collision energy in joint can be transferred from partial input energy by increasing suitable clearance,thus the elastic deformation and impact vibration will be reduced.This may provide a reference for the research of mechanical operating mechanism.