基于离散元法的颗粒高速压制模拟及动态力学分析

High velocity compaction simulation and dynamic mechanical analysis of particles based on discrete element method

采用三维离散单元法对高速压制条件下铝粉颗粒的动态响应进行了数值模拟,并与实验结果进行对比分析。结果表明,数值模拟与实验所测得的结果基本相同;在高速压制过程中,粉体的扰动呈不规则的弧形分布;在压制初期,会出现整体受力不均匀的现象,随着压制的进行,不均匀现象得到改善,粉体表现出较强的自组织性;在单次加载过程中,颗粒会发生多次碰撞;在致密化阶段,上层的部分颗粒会先发生变形并重排,中下层颗粒以重排为主;进入变形阶段后,所有颗粒的受力情况基本相同。

Three-dimensional discrete element method(DEM) was applied to simulate the dynamic response of aluminum powders under the high velocity compaction(HVC), and the results were compared with the experimental data. In the results, the numerical simulation is basically the same as the experiment results. The powder disturbance shows the irregular arc distribution during the high velocity compaction. There will be an uneven phenomenon of overall force in the initial stage of compaction;as the compaction keeps going, the uneven problem will be improved, and the powders exhibit the strong self-organization. In the single-pass loading process, the particle impact will occur repeatedly;in the densification stage, the upper particles will deform and rearrange, and the middle and lower layers will be dominated by the granular rearrangement;in the deformation stage, the force of all the particles is basically the same.