基于非弹性回复的先进高强板回弹研究

Research on springback of advanced high-strength-steel plate based on non-elastic recovery

针对先进高强钢卸载时存在的明显非弹性回复的情况,从能量角度深入分析非弹性回复现象的机理,考虑加载-卸载过程的非弹性回复应变并引入双屈服面理论,建立一种考虑塑性预应变及卸载应力变化的卸载弹性模量模型本构来进行回弹仿真预测。并以某梁类零件为例,对比了新卸载弹性模量本构、Yoshida本构、常规弹性模量本构等的回弹仿真结果与试验结果的区别。研究结果表明:非弹性回复应变具有可逆性与消耗能量的特点,是引起非弹性回复行为的主要原因;新的材料本构模型回弹仿真结果与试验值吻合较好,对比其它模型仿真结果其精度有所提高。

Considering the obvious non-elastic recovery phenomenon of advanced high strength steel plate after unloading, its principle was analyzed deeply from energy aspect, and based on the pre-plastic strain and unload elastic modulus, the material constitutive model was set up to simulate and predict the spring by the theory of non-elastic recovery strain with two-yield-surface in the loading-unloading process. For the beam-type parts, it was compared the differences of the experimental results with the springback simulation results, which were obtained by the new unload elastic modulus constitutive, Yoshida constitutive and conventional elastic modulus constitutive. Re- search results show that the non-elastic recovery strain is of the characteristics of reversibility and energy consumption, and it is the most important reason of non-elastic recovery phenomenon. Furthermore, the results of springback simulation obtained by the new material con- stitutive model are in good agreement with the experimental results, and the accuracy of the springback simulation is improved comparing with that of other models.