集沙铲集沙过程的受力状况仿真分析与试验研究

集沙铲是某款小型铁路轨道除沙车的重要工作部件。集沙铲在实际使用中受到的冲击力大、铲板刃缘变形严重，为改善集沙铲受力状况，对集沙铲集沙过程的受力状况进行研究。应用离散单元法（discrete element method，DEM）与多体动力学，分别对相同工况下直板、15°板和30°板集沙铲的总受力和X、Y、Z三个方向的受力进行比较。同时，利用离散单元法对不同时刻集沙铲切分沙土瞬间的沙土颗粒的速度分布状况进行分析。最后设计并制作了集沙铲试验台，模拟了集沙铲集沙过程，并对直板和30°板集沙铲的工作转矩进行了测量。研究结果表明：增大集沙铲铲板刃缘倾角可以减小集沙铲的冲击受力；随着集沙铲铲板刃缘倾角变化，集沙铲触沙瞬间沙土颗粒的速度分布发生明显变化。研究结果对改善集沙铲冲击受力具有一定指导意义，同时也对利用离散元法研究铲板-沙土相互作用过程具有一定指导意义。

Simulation analysis and experimental study on stress state of sand-collecting shovel during sand-collecting process

The sand-collecting shovel is an important part of a small track sand removing vehicle. In practical working, a large impact force occurred on the shovel which developed a large deformation on the edge of the shovel. In order to improve the force condition of the shovel, the stress state of sand-collecting shovel during the sand-collecting process was studied. By the discrete element method (DEM) and multi-body dynamics, the total force and the force in X, Y and Z directions of sand-collecting shovel with straight board, 15° board and 30° board under the same working conditions were compared, respectively. At the same time, the velocity distribution of sand particles in the instant of cutting sand by shovel at different time was analyzed by using the DEM. Finally, a sand-collecting shovel test bench was designed and manufactured to simulate the sand-collecting process，and the working torques of the sand-collecting shovel with straight board and 30° board were measured. The research results showed that increasing the edge inclination angle of the sand-collecting shovel board can reduce the force of the sand-collecting shovel. Meanwhile, with the changing of the edge inclination angle of the sand-collecting shovel board, the velocity distribution of the sand particles obviously changed when the sand-collecting shovel touched the sand. The research results have guiding significance for improving the impact force of sand shovel and studying shovel-sand interaction process by using DEM.