凸模直径对拼焊板极限胀形成形性能影响的数值模拟  

Numerical simulation of influence of punch diameter on limit bulging properties for tailored welded blanks

作　　者：陈水生[1] 孙东继[2] 

机构地区：[1]河南理工大学机械与动力工程学院,河南焦作454000 [2]上海通用汽车有限公司,上海210206

出　　处：《锻压技术》2015年第8期41-46,共6页Forging & Stamping Technology

基　　金：河南省教育厅科学技术研究重点项目(14A460013);河南省科技攻关计划资助项目(142102210130)

摘　　要：为了获得极限胀形高度试验中合理的凸模直径D,采用试验和有限元法研究D对拼焊板胀形成形特征的影响。建模过程中,焊缝作为独立部分被赋予材料性能和宽度;拼焊板与模具间的摩擦系数通过试验与仿真载荷-位移曲线对比确定。通过对比试验与仿真结果即极限胀形高度和开裂位置,证明了有限元模型的合理性。基于模型,分析D对相对极限胀形高度及极限应变的影响。结果表明,对板厚比大的拼焊板,D对相对极限胀形高度和极限应变有显著影响,对板厚比小的影响较小。D存在一个临界值,当超过临界值后,极限胀形成形特征稳定。当摩擦系数为0.08时,板厚比较大的冷轧镀锌板DC56D+Z拼焊板极限胀形试验的D临界值约为100.0 mm。To probe the reasonable punch diameter D from the limit bulging height （LBH） test, the influence of D on the formability of tailor welded blanks （TWBs） was discussed by the experiment and finite element （FE） method. In the model of TWBs, the weld was treated independent part and given with the weld properties and the width. The friction coefficient between tools and TWBs was determined by comparison of the load - displacement curves of the experiments with that of the simulations. The established FE model was proved to be available by comparing the limit bulging height and the crack location in the experiment with that in the simulation. The influences of D on the relative LBH and the limit strain were analyzed based on the FE model. The results indicate that when TR is large, D has signifi- cant effect on the formability of TWBs ; otherwise, D has little effect. There is a critical value for D. When D exceeds the critical value, the forming formability of TWBs maintains steady. When the friction coefficient is 0. 08, critical value D in the limit bulging test is 100 mm for the cold rolled galvanized sheet and tailor welded blanks with a larger TR.

关 键 词：拼焊板 凸模直径 极限胀形高度 极限应变 临界直径 

分 类 号：TG306[金属学及工艺—金属压力加工]