中文摘要：

以国际板料成形数值模拟会议（Numisheet 2011）上提出的第四个标准考题为研究对象，应用ABAQUS对DP780高强钢板弯曲及回弹过程进行模拟。结果表明：随着网格划分尺寸减小，回弹量逐渐增大，网格密度对板料弯曲回弹量有较大的影响；随着摩擦因数的逐渐增大，回弹量先快速增大，然后缓慢减小。将得到的与试验值相匹配的网格尺寸（2．75mm）和摩擦因数（0．1）应用于板料预变形之后再拉深弯曲过程模拟，结果发现：板料预变形之后拉深弯曲回弹量增大。将模拟值与Numisheet2011会议得到的试验值对比发现，板料弯曲模拟与试验的回弹变化趋势相同，且3个回弹表征量的模拟误差都在10％以内。

英文摘要：

The fourth standard examination question in Numisheet2011 was taken as the research object, and the bending and spring-back process of DP780 high strength steel was simulated by ABAQUS. The results indicate that with the decrease of grid division dimension, the spring-back value increases gradually; and the grid density has a biggish effect on the sheet metal bending spring-back value. With the gradual increase of friction coefficient, the spring-back value increases quickly at the beginning and then decreases slowly. The obtained mesh size （2.75mm） and friction coefficient （0.1） which matched with the ex- perimental values were applied to the simulation of pre-stretching sheet metal forming process. The results show that the spring-back value after pre-stretching increases. Comparing the simulated values with experimental values obtained from Numisheet2011, the precision with and without pre-strain was all above 90% .