中文摘要：

运用统一强度理论对两、三层挤压预应力组合凹模进行了等强度分析,导出了包含反映材料拉压性能差异的参数α及反映中间主应力效应的参数b的计算其强度的系列计算式,并据此编写了计算程序。通过程序作出了3组参数α、b取不同值时组合凹模强度与R/r关系的曲线,得到了参数α、b影响组合凹模强度的规律。结果表明,b的取值从0到1逐渐增大,组合凹模强度也逐渐增加,对于有明显拉压异性的合金钢,如取参数α≠1来考虑材料拉压异性,则组合凹模的强度可提高。

英文摘要：

Applying unified strength theory, two-layer prestressed combination die and the three-layer one by equal strength principle were analyzed, and series of calculation formula of the die strength containing the tension-compression ratio aand the intermediate principal stress parameter b were derived, and corresponding program was writed. By the program developed, three sets of curves about the die strength and R/r relation with different values of aand b were presented. Effects of the parameters,aand b on combination die strength were obtained. The results show that die strength is increased with in- creasing in b changed from 0 to 1. As to alloy steel with significantly different tension and compression, when , a≠lstrength of the combination die can be increased.