滚弯成形解析建模与数值分析

摘要

An analytical model is developed through elastic-plastic mechanics, considering strain-hardening of material, and the formulas of stress, strain, residual stress, springback are given. Based on nonlinear FEM package, the dynamic simulation of roll-bending is also carried out. Then stress state, plastic strain distribution, residual stress and springback are analyzed, together with effect of displacement of toproller and multi-pass. The result shows that curvature near the start point is not uniform, but curvature of the middle section of the plate is very uniform if the rolling time is long enough;the radius of bended plate is a power function of displacement of toproller;multi-pass can reduce the fluctuation of curvature, the maximum stress and strain of the plate in bending. Finally, the analytical model and FE model are verified by experiments.%建立了考虑材料塑性强化的滚弯成形力学分析解析模型,推导出了应力应变、残余应力以及回弹半径计算公式.基于非线性有限元软件,对滚弯成形进行了动态模拟,对应力应变状态、塑性应变分布、残余应力以及回弹等进行了分析计算,结果表明:板料滚弯成形初始效应明显,下压点附近曲率不均匀；采用足够的滚弯时间后,中间段的曲率均匀度很好；成形半径与上辊下压量呈近似幂函数关系；多道次滚弯可以减小两端的曲率波动和最大应力应变.最后通过与滚弯成形试验数据的对比,分析和验证了解析模型与数值模型的适用性和精度.