若干关键技术
(上海交通大学 模具CAD国家工程研究中心,
上海 200030)
摘 要: 推导了采用六面体等参单元网格划分的金属三维挤压成形过程数值模拟中的摩擦力功率泛函在局部坐标系的一阶和二阶偏导数的表达式, 提出了有效的三维六面体网格划分和网格质量控制技术处理方法。 以此为基础, 建立了三维刚塑性有限元数值模拟系统和六面体网格再划分系统。 方坯料反向挤压过程数值模拟的结果与实验非常吻合, 验证了所推导的公式和开发的系统; 圆坯料侧向挤压过程的模拟验证了提出的网格质量控制技术的第三种方法。
关键字: 挤压工艺; 数值模拟; 三维刚塑性有限元法
(National Die & Mould CAD Engineering Research Center, Shanghai Jiaotong University,Shanghai 200030, China)
Abstract:The derivatives of the first order and the second order of the calculus of the function of the frictional power induced by the boundary friction force were deduced, which will be the foundation in simulating 3-D extrusion processes. In addition, the effective methods for initial meshing and mesh quality control were presented. The self-developed simulation system and remeshing system coupled with the commercial system DEFORM3D were used to simulate several extrusion processes, and the simulation results fit well with the experimental results, which verified the reliability of the proposed methods.
Key words: extrusion; numerical simulation; 3-D rigid-plastic finite element formulations