交变气动冲击锤瞬态冲击特性分析

Analysis of the Transient Impact Performance of Alternating Pneumatic Impact Hammer

应用一维瞬态应力波特征线法对交变气动冲击锤的冲击系统进行理论分析,研究冲击部件之间瞬态波的传播及撞击接触面撞击力的变化规律。重点利用非线性动力学分析软件LS-DYNA对交变气动冲击锤的冲击系统模型进行仿真计算,并与理论分析结果对比,验证了仿真模型具有较高的可靠性。研究中计算分析活塞初始冲击速度、工作介质性质对撞击接触面撞击力和活塞冲击反弹速度的影响,得出了活塞瞬态动力特性与活塞初始冲击速度和工作介质性质的关系。研究结果表明,不同物理特性的工作介质对应的气动冲击锤瞬态冲击特性也不同。研究结论为进一步研究气动冲击锤以活塞的冲击特性来判断工作对象的性质提供了理论依据和实际参考。

Based on the method of characteristics, the impact system of alternating pneumatic impact hammer is analyzed theoretically. The transient wave’s transmission between different impact parts and the variation of the force of the impact contact interface is studied. The impact system model of pneumatic impact hammer is simulated by nonlinear FEM program, LS-DANA, and the numerical model is verified very effectively by theoretic analysis. The effects of the piston’s initial impacting velocity and the nature of working medium on the force of the impact contact interface and the rebound velocity of the piston are analyzed and calculated, respectively. The results show that, there is a corresponding relationship between the nature of working medium and the transient dynamic characteristics of the pneumatic impact hammer. The final conclusions provide reference for further studying of using the hammer rebound to carry out a real time measurement of the nature of working medium.