宽板大曲率半径纯弯曲回弹量理论分析

针对各向异性板料的大曲率弯曲回弹问题,建立了服从Hill屈服准则和指数强化模型的平面应变纯弯曲的回弹理论模型。应用该模型计算了Numisheet’2002无约束柱面弯曲回弹的考题,与实验结果和其它理论模型计算值的对比表明,模型的回弹结果与实验值很接近,其精度优于其它算法。同时还表明,屈服准则的选取对预测板料回弹量有着较大影响,而强化模型的影响则不是很显著。

THE SPRINGBACK OF WIDE METAL SHEET AFTER LARGE RADIUS PURE BENDING

For the springback problems of wide anisotropic metal sheets after large radius pure bending, a mathematical model is proposed based on Hill’s yielding criterion. Exponential hardening and plane strain condition are assumed. The model is validated by the Benchmark problem of unconstrained cylinder bending in Numisheet’2002, and the results are compared with experimental data and the computed data by other parallel method. The results of the proposed model are more close to the experimental data than those of other models. It was also demonstrated that yielding criterion imposes an larger effect on springback than hardening expression.