电镦成形过程电热力耦合有限元模拟若干关键技术的处理

电镦成形过程中坯料局部连续地被直接通电加热后变形 ,且变形量非常大。在运用有限元法对成形过程进行电热力耦合数值模拟分析时 ,如何处理电阻热、变形体积的连续增加以及大变形造成网格的畸变等问题 ,是能否获得正确分析结果的关键。作者通过分析坯料变形区域电场的分布 ,采用复合变体积和动态网格划分等方法 ,成功地解决了这些关键技术 ,并将其运用于有限元程序设计中 ,从而获得了满意的分析结果。

Research on some key techniques of coupled thermo-mechanical FEM simulation for electric upsetting process

In electric upsetting, the workpiece is heated by electrifying and deformed locally and continuously with very large upsetting ratio. When coupled electric-thermo-mechanical FEM is used to analyze the forming process, it is the key for obtaining correct simulation results to deal with resistance heat, adding of forming volume and mesh aberration caused by large deformation. Based on analyzing electric field distribution of deformation zone, techniques of variable volume and dynamic remeshing were applied to successfully resolve these key problems. These key techniques were used in FEM program, achieving satisfactory results.