基于成形角度分配优化函数的辊弯成形边波及纵向弯曲缺陷研究

Edge and Longitudinal Bending Defects in Roll Bending Forming Based on Forming Angle Allocation Optimization Function

目的研究板材辊弯成形中弯曲角的分配方式,改善辊弯过程中出现的边波和纵向弯曲等各种缺陷,提高成形精度与质量。方法以小截面型材帽形辊弯件为研究对象,首先提出五边界条件成形角分配函数,并进行成形角度优化,得到最优的成形角分配方法。其次研究各弯曲角度分配方式对板材产生的主要缺陷如边波及纵向弯曲的影响规律,并进行辊弯成形实验验证。结果经过实验验证基于四边界条件的辊弯峰值纵向应变从4.15%降低到基于五边界条件的1.18%。验证了θ_(N/3)=33%×θ_(0)时辊弯成形角度分配的合理性。结论基于优化的弯曲角分配方式的纵向应变、翘曲波动量和偏差值、最大高度偏差都小于其他分配方式的相应值,表现出其在成形工艺上的优越性。研究结果为合理设计类似帽形件或复杂截面形件的辊弯工艺提供一定的理论指导。

The work aims to study the distribution method of bending angle in roll bending forming of sheet, solve different defects such as edge and longitudinal bending in roll bending and improve the forming precision and quality. With hat-shaped bending part of small cross section as object, the forming angle distribution function under five boundary conditions was proposed and the forming angle was optimized to obtain the optimal forming angle distribution method. Secondly, the effects of the distribution of bending angles on the main defects such as edge and longitudinal bending were studied, and the roll bending experiments were carried out to verify the results. Experimental verification showed that the peak longitudinal strain based on four boundary conditions decreased from 4.15% to 1.18% based on five boundary conditions. The rationality of forming angle distribution during roll bending when θ_(N/3)=33%×θ_(0)was verified. The results show that the longitudinal strain, warpage fluctuation and deviation and maximum height deviation of the optimized bending angle allocation method are all smaller than those of other allocation methods, which shows its superiority in forming process. The research results provide theoretical guidance for rational design of roll bending process of similar hat-shaped parts or complex section shaped parts.