【摘要】 利用研制的集增压器、冲液器、滑动胀形模具于一体的超高压液压胀形装置,在普通液压机上进行汽车桥壳样件的液压胀形胀裂试验,绘制出液体胀形压力与管坯压缩量不同的匹配关系时(即不同加载路径)的胀形极限图,揭示出极限胀形系数与管坯轴向应变存在线性关系kr=1+δ5-1.72εz,并与材料断后伸长率δ5有关。给出管坯胀裂时的应变判据εn=δ5及应力判据σθ=2σb,即胀裂时管坯壁厚方向的应变等于材料的延伸率,环向应力等于材料拉伸强度的2倍。研究成果能为理论研究及工程应用提供依据。更多还原

【Abstract】 The hydro-forming bursting tests of the designed sample of automobile axle housings is done in the commen press, with the utlization of the ultrahigh pressure hydro- forming device integrating the supercharger and the filler within the sliding bulging die. The bulging limit diagram is drawn, according to the different loading path which indicates the matching relation between the bulging pressure and the tubular axial compression. The function between the bulging limit coefficient and the tubular axial strain is revealed , that is, k r = 1 + δ 5? 1.72ε z, and kr is related to the percentage elongation δ 5of material. The bursting strain criterion ε n= δ 5 and the bursting stress criterion σ θ= 2σb are given, that means the wall-direction strain is equal to the percentage elongation and the circumferencial stress is equal to two times of the strength limit of the material. The results offers a basis to the theoretical research and the practical applying.更多还原