模具参数对钨合金液力挤压应力场及模具压力影响数值仿真研究

Numerical simulation on influence of mold parameters on stress field and mold pressure for hydraulic extrusion of tungsten alloys

用弹塑性有限元法研究模具参数对钨合金液力挤压应力场及模具压力的影响规律。结果表明:随模具角度的增大,制品表面的拉应力、周向拉应力、外圆附近剪应力呈不断增大的趋势;摩擦因数对轴向和周向应力的影响较小,径向拉应力随摩擦因数的增大而减小;随着挤压比的增大,表面轴向最大拉应力、径向压应力随之增大,而周向应力、径向拉应力随挤压比增大而减小;模具角度为30°时,模具压力最小;随着挤压比的增加,模具压力增大。

Numerical simulations on the influence of mold parameters on stress field and mold pressure for hydraulic extrusion of tungsten alloys were performed using elastoplastic finite element method. The results show that surface tensile stress and circumferential tensile stress and outer circle shear stress of products increase with the increase of mold edge. Radial tensile stress decreases with the friction coefficient increasing,while axial stress and circumferential stress are less affected by friction coefficient. Maximum tensile stress of surface axial and radial compressive stress increases as extrusion ratio increases,while circumferential stress and radial tensile stress decrease. The value of mold stress reaches the minimum when the mold edge is30°. The value of mold stress increases with the increase of extrusion ratio.