气腿式凿岩机活塞的非线性动力学特性

以气腿式凿岩机活塞为研究对象,根据实际工况建立了活塞和钎杆冲击系统的有限元模型,利用ANSYS/LS-DYNA软件对活塞冲程过程进行了非线性动力学特性分析,得到了活塞与钎杆各个时刻的应力应变情况.结果表明,活塞冲击能的计算结果与实验结果相比误差较小;活塞的最大应力发生在撞击端面上,此外活塞的花键根部也是受力较大的薄弱环节,最大应力介于其疲劳极限与屈服极限之间;活塞的失效形式为端面接触疲劳和花键根部处疲劳断裂,与实际情况十分吻合.

Nonlinear Dynamic Characteristics of Air-Leg Rock Drill Piston

Taking a piston of air-leg rock drill as the research object， a finite element analysis model of the impact system including the piston and drill rod was set up based on the actual conditions. Its nonlinear dynamic characteristics were analyzed using the ANSYS/LS-DYNA software. Therefore， the stresses and strains of the impact system at different time were obtained. The results showed that there are minor deviations between the calculated and experimental results. The maximum stress， which is greater than the fatigue limit and less than the yield limit， appears at the impacting face. The spline root of the piston with strong stress is also a weak link. The failure form of the piston is the contact fatigue of the end face or fatigue fractures of the spline root， which coincides well with the actual situation and provides a scientific basis for reliability design of the piston.