塑性强化材料辊式矫直力学行为研究

采用弹塑性弯曲理论与应力线性叠加原则对塑性强化材料连续弹塑性弯曲过程力学行为进行分析,考虑应力传递效应对矫直过程的影响,建立七辊辊式矫直机连续弹塑性弯曲矫直过程力学模型。通过对比试验结果及理论计算值,两者偏差平均值在8%以内,验证了理论分析方法的正确性。利用该模型,对不同的矫直策略进行分析。结果表明,大变形矫直策略残余应力与残余曲率控制能力均强于小变形矫直策略;由于应力传递效应对矫直过程的影响,使得小变形矫直策略随矫直过程的深入,残余曲率并未向零点逐步收敛,而是在一定范围内波动;大变形矫直策略由于采用了逐步矫直的工艺设定思想,使其可以达到矫直的目的。这些分析结果为工业生产中矫直策略的选取提供了理论依据。

Research on Roller Straightening Mechanical Behavior of Plastic Hardening Material

The continuously elastic-plastic mechanical behavior of the plastic hardening material is analyzed by the elastic-plastic bending theory and stress linear superposition principle, and a continuous elastic-plastic bending-straightening processing mechanical model of the leveler with seven rollers is established considering the effect of stress transfer effect on straightening process.By comparing the experimental results and theoretical calculations, the average deviation is less than 8%, which verify the theoretical analysis is correct.Using this model, different straightening strategies are analyzed. The results show that the large deformation straightening strategy is better than the small deformation straightening strategy in the controlling ability of the residual stress and residual curvature.Because of stress transfer effect on straightening process, the residual curvature does not converge to zero but fluctuate within a certain range with the straightening processing by the small deformation straightening strategy;The large deformation straightening strategy adopts gradual straightening process setting method, so it can achieve the purpose of straightening. All these results provide a theoretical basis for straightening strategy selection in industrial production.