基于多场耦合的电镦成形工艺有限元模拟

Multi-field coupled finite element simulation of electric upsetting

结合实际生产经验在DEFORM软件平台中建立电-热-结构多场耦合的电热镦粗有限元模型,并采用多组工艺参数进行模拟计算,分析不同电流密度和镦粗压力对成形尺寸、温度场和等效应变速率场的影响。结果表明:电镦初期,由于砧座与工件之间接触电阻的存在,温度迅速升高,之后通过工件自身电阻产热,温度基本趋于稳定;等效应变速率最大值存在于工件脖颈段;工件蒜头最大半径和最高温度随电流密度增大而增大;镦粗压力增大使得蒜头最大半径增大而工件最大温度下降。对电镦过程中产生的缺陷进行模拟分析,得到相对优化的工艺参数,模拟结果与试验结果吻合较好。

Considering the actual production experience,an electro-thermal-structural multi-field coupled finite element model of upsetting was established based on DEFORM software platform,multiple sets of process parameters were used for simulation and calculation,and the influences of different current densities and upsetting pressures on forming dimension,temperature field,and equivalent strain rate field were analyzed. Results show that the temperature increases rapidly due to the contact resistance between the anvil holder and the workpiece during the initial period of electric upsetting,and then tends to be stable through the heat production from the resistance of the workpiece. The maximum equivalent strain rate exists at the neck of the workpiece. The maximum radius of garlic head and the maximum temperature increase with the increase of current density. The maximum radius of the garlic head increases while the maximum temperature of the workpiece decreases with the increase of upsetting pressure. The defects in the process of electric upsetting were simulated and analyzed,the optimized process parameters were obtained. The simulation results are in good agreement with the experimental results.