铝合金轴固定件热挤压成形的有限体积法模拟研究

由于变形剧烈，复杂铝型材挤压成形有限元模拟会因网格不断重划分而精度欠佳。文中基于可以有效避免网格重划分难题的有限体积法，对铝合金门轴固定产品的热挤压过程进行数值模拟，详细分析挤压成形中各个阶段金属流动情况以及应力、应变、温度、速度等场量的分布变化情况。棒料进人模口至完全流出工作带这段时间是型材挤压最为困难的阶段，材料在工作带处的应力、应变最大，温度最高，因而对模具工作带处造成的磨损也最为严重。进人到最终稳定挤压阶段时挤压方向金属流速计算值与理论挤出速度吻合很好。模拟结果表明所用有限体积法是有效的，可以为铝型材挤压的模具设计与工艺参数的选择提供理论指导。

SIMULATION OF ALUMINUM FIXTURE PART HOT EXTRUSION PROCESS WITH THE FINITE VOLUME METHOD

Due to the sever plastic deformation, simulation of complicate aluminum profile extrusion with finite element method can not work well because of continuous mesh rezoning. The hot extrusion process of an aluminum fixture part is simulated with the finite volume method that can avoid rezoning problem effectively. The evolution of stress, strain, temperature and velocity is analyzed in detail. After entering flat die, aluminum material undergoes a crucial deformation process before flowing out of die beating. The maximum stress, strain and temperature in aluminum material are all fotmd to occur near the die bearing, so the severest wear happens to die near die bearing. The calculated extrusion speed in the stable extrusion stage is in good consistent with the theoretical one. The simulation results show the validity of employed finite element method and it can provide theoretical instruction for aluminum extrusion die design and technique parameters selection.