变壁厚筒形构件辊挤成形过程数值模拟

Numerical simulation on rolling-extrusion forming of variable thickness cylinder

为解决变壁厚筒体构件制造过程材料利用率低、机加工时长等问题,提出一种辊挤成形工艺。该工艺通过3个被动旋转辊轮的辊压作用实现坯料的塑性变形。借助Deform-3D软件建立变壁厚筒形构件辊挤成形热力耦合刚黏塑性有限元模型,对辊挤过程进行数值模拟,获得了辊挤过程中载荷-行程曲线、等效应力与应变场以及温度场的分布规律。研究了工艺参数对成形构件变形均匀性的影响。结果表明:工件变形的不均匀性随着辊挤速度和摩擦因数的增大而增大,随变形温度的升高而减小。

The rolling-extrusion technique for the mass production of variable wall thickness cylinder parts was put forward tor reducing the machining time and increasing the material utilization. In this process, material was formed by means of three passively rotational tools. A coupled thermal-mechanical rigid-viscoplasticity FEM model for rolling-extrusion of variable thickness cylinder parts was developed based on the Deform-3D software. The distribution of equivalent strain field, equivalent stress field, temperature field and the load- stroke curve during the rolling-extrusion forming process was obtained. Furthermore, the influence of process parameters on the deformation uniformity was analyzed. The results show that the deformation nonuniformity of billet increases with the increase of punch speed and friction factor, and with the decrease of initial temperature of billet.