校正力对宽板弯曲回弹影响规律的研究

Influence law of bottom-force on springback in wide sheet bending

为了简单有效地控制高强度钢的回弹,研究了校正力对板料弯曲回弹的影响.根据校正弯曲受力特点,在考虑了应力-应变分布、受力边界条件、刚塑性材料模型和梅西屈服准则的基础上,建立了校正弯曲下的回弹预测模型,确立了校正力和回弹之间的对应关系.进一步采用自制的1t伺服压力机进行了试验,结果表明:增大校正力能有效降低回弹,回弹预测值和试验值一致,校正弯曲回弹预测模型能够提供较为真实的近似解;合理设置校正力可以有效控制和稳定回弹,为高强钢的回弹控制提供了简单有效的措施;回弹预测模型建立了校正弯曲力和回弹之间的定量关系,为模具及工艺参数的设置提供了可靠的依据.

To control the springback of high strength sheet metals effectively,the influences of bottom-force on springback were studied.Based on the analysis of stress,the springback prediction model considering bottom-force was presented for bottoming bending,and the springback could be deduced under different bottom-forces.This model considered stress and strain distributions and taken tress boundary condition into account.A rigid-plastic material model and Mises yield criterion were incorporated in the model.The experiments of V-bending by using 1 t servo press were conducted.The results show that the springback can be reduced with increasing the bottom-force and the springback prediction can coincide with the test results well.Using bottom bending with reasonable bottom-force gives a useful method to control the springback of high strength sheet metal,and the springback prediction model supplies an important instruction to design of die.