基于Matlab与Ls-dyna的气缸冲击仿真解析

气缸活塞撞击到前端盖时，活塞杆和衬套间会发生较大应力导致部件磨损产生气体泄漏.为了准确了解气缸运行过程中各物理量的集中式参数和分布式参数的变化情况，提出一种采用Matlab与ANSYS/Ls-dyna对气缸运行和内部受力进行联合仿真的方法.通过Matlab获得气缸内压力的仿真结果，以此作为Ls-dyna的仿真条件可以得到更为精确的位移、速度、活塞杆与衬套间动态应力分布和径向震荡等情况.仿真结果表明气缸冲击过程中，活塞与活塞杆出现明显的倾斜，气缸衬套与缸筒上呈现一些明显的受力点，气缸的活塞杆冲击速度、负载分别与其所承受的最大等效压力近似成正比关系. 

Analysis on Cylinder Impact Based on Matlab and Ls-dyna

The piston rod and bush sustain large stress when the piston rod suddenly impact on the end cover of the cylinder, that will lead to wear and then cause leakage. In order to study the changes of lumped parameters and distributed parameters of the physical quantities during the cylinder impact, the Matlab and ANSYS/Ls-dyna were used to complete a union simulation on the cylinder system. Taking the simulation results obtained with Matlab software as the simulation conditions of Ls-dyna, the union simulation system can get more accurate displacement, velocity, the dynamic stress distribution of the piston rod and the bush, and the radial shake situation. The simulation result shows that the piston and piston rod appear an obvious tilt during the cylinder impact, and there are some obvious stress points in the bush and cylinder tube. The piston rod velocity, load of cylinder has a proportional relationship with the maximum equivalent stress of cylinder.