宽板V型自由弯曲智能化控制过程的解析定量描述

Analytic description of intelligent control of V-shap free bending of wide sheet metal

板料在弯曲卸载过程中,由于弹性变形回复,从而产生回弹。回弹的结果使弯曲件的精度降低。影响回弹的因素很多,也很复杂。根据弹塑性弯曲理论,在平面变形假设的前提下,考虑了材料的硬化、各向异性及弹性变形,对宽板V型自由弯曲应力应变进行了分析,得到了弹塑性交界处曲率半径,推导出了弯曲力及目标弯曲角随弯曲行程变化的关系式。理论计算与实验及数值模拟结果进行了比较,为宽板V型自由弯曲智能化控制中参数识别及预测模型输入层和输出层变量的确定提供了理论依据。

The springback of sheet metal after unloading badly affected the tolerance of bend parts. There are many and complex factors resulting in the spring back. In this paper, based elastic-plastic bending theory, stress and strain of V-shape free bending of wide sheet metal is analyzed on the assumption of plane strain, involving the harden ability, anisotropy and elastic deformation of sheet metal. Curvature radius of elastic-plastic point is obtained, and an formula of relationship between bending fore, aim bending angle and punch stroke is deduced. Solution of theory is compared to experiment and simulation. It provides the theory base for the confirmation of parameter identification and prediction model of the import layer and export layer in intelligent control of V-shape free bending of wide sheet metal.