热锻模具结构参数与模具应力关系的数值模拟

Numerical simulation of relationship between structural parameters and mold stress for hot forging mold

为降低深型槽锻模型槽底部过渡圆角处的开裂风险,为锻模结构设计提供指导,通过所设计的模具探究了结构参数(型槽底部过渡圆角半径R、毛边槽桥部单边高度h、入口圆角半径r以及拔模斜度α)对模具应力(模具的最大主应力)的影响。采用单因素变量法,设计了4组模拟实验,共计24次有限元模拟,并通过对比成形载荷的模拟结果和已有研究预测结果来验证模拟的正确性。模拟结果表明:σ_(max)(模具应力最大值)随着R的增大而减小,且二者呈现出较好的线性关系,即R增大1 mm,σ_(max)下降约40 MPa;模具整体应力水平随着h的增大而迅速减小,但减小程度逐渐降低;r在1~7 mm变化时对模具应力的影响较小;α对模具应力的影响机理较为复杂,但总体而言,增大α会导致模具应力轻微上升。

In order to reduce the cracking risk of transition fillet of the groove bottom of deep groove forging mold,and provide guidance for the structural design of forging mold,a mold was designed to study the influences of structural parameters(transition fillet radius of groove bottom R,single side height of bridge for flash groove h,inlet fillet radius r,draft angleα)on mold stress(maximum principal stress of mold).Then,four sets of simulation experiments were designed by using the single factor variable method,and a total of twentyfour finite element simulation experiments were carried out.Furthermore,the simulation correctness was verified by comparing the simulation results of forming load with the prediction results of existing studies.The simulation results indicate thatσ_(max)(maximum mold stress value)decreases with the increasing of R,and the two show a good linear relationship,that is,R increases by 1 mm,andσ_(max) decreases by about 40 MPa.The overall stress level of mold decreases rapidly with the increasing of h,but the degree of reduction decreases gradually.r has little effect on the mold stress when r changes from 1 mm to 7 mm,and the influence mechanism ofαon the mold stress is more complicated.In general,increasingαinduces a slight increase in the mold stress.