基于Gardiner公式改进的船体外板回弹预测方法

Improved Springback Prediction Method of Hull Plate Based on Gardiner Formula

船体外板在冷弯加工过程中会发生回弹现象,回弹导致冷弯成形精度降低,从而使生产周期变长,因此,回弹预测对于准确制造产品是很重要的.文中基于单向应力和平断面假设,考虑到材料在加工硬化阶段更符合幂硬化现象,以幂指数函数表示材料的真实应力应变关系,对Gardiner公式做出改进,推导出一种新的回弹预测公式.实验数据表明,当应变硬化指数较小时改进的公式回弹预测的误差小于Gardiner公式计算的回弹量的误差,在加工小曲率板材时改进公式计算的回弹量明显优于Gardiner公式计算的结果.

Springback will occur in the cold bending process of the hull plate. Springback causes the precision of cold bending forming to decrease, thus making the production cycle longer. Therefore, springback prediction is very important to accurately manufacture products. Based on the uniaxial stress state and the flat section assumptions, considering the fact that the material is more consistent with the power-law-hardening phenomenon in the work hardening stage, the Gardiner formula was improved and a new springback prediction formula was deduced. The experimental data show that when the strain hardening exponent is small, the springback prediction error of the improved formula is smaller than the springback calculated by Gardiner formula, and the springback calculated by the improved formula is obviously better than that calculated by Gardiner formula when processing small curvature plates.