基于Oyane准则的金属板材渐进成形破裂预测

Fracture Prediction of Sheet Metal Incremental Forming Based on Oyane Criterion

针对渐进成形中的破裂缺陷,将Oyane准则引入数值模拟中,有效预测了渐进成形中金属板料的成形极限.首先,针对DC56D+Z钢板,基于获取的Oyane准则材料参数,通过试验与数值模拟确定了破裂积分值I=4为破裂的临界条件.然后,基于响应面法建立了工艺参数与I积分值之间的非线性模型,且通过方差分析验证了该模型的有效性.研究得出:该数值模型可以有效预测最大破裂积分I值,I值随着成形角α、层间距Δz和工具头直径d的增大而增大,3个工艺参数的影响作用逐渐减弱,且α&Δz、α&d两种组合的交互作用影响较大.

In order to solve the fracture defects in incremental forming,the Oyane criterion was introduced into numerical simulation,and the forming limit of sheet metal in incremental forming was effectively predicted.Firstly,based on DC56D+Z plate and its material constants of the Oyane criterion,the critical value of fracture integral(I=4)was determined by experiment and numerical simulation.Afterwards,by using response surface methodology,a nonlinear model between the process parameters(forming angelα,interlayer spacingΔz and diameter of tool head d)and I was established,and the effectiveness of the model was verified by a parametric analysis.It is found that the value of I can be effectively predicted by the numerical model.The value of I increases with the increase ofα,Δz and d.The influence ofα,Δz and d on I value gradually decreases in sequence.In addition,the relative large interaction effects ofα&Δz andα&d are found.