管件数控弯曲工艺参数对回弹的影响

摘要

管件数控绕弯卸载后会产生回弹现象,为更好提高船舶管件绕弯成形质量,需要对弯曲卸载后的回弹进行有效控制.基于有限元软件Dynaform平台建立船用20#管数控弯曲及回弹的三维有限元模型,模拟了管件绕弯卸载后的回弹过程,通过正交实验设计,对回弹角度数据进行极差分析和方差分析,研究了工艺参数对回弹影响的显著性及规律.结果表明:对回弹角度影响显著的工艺参数顺序依次是:防皱模与管件间隙、弯模与管件间隙、芯棒前伸量、镶块与管件间隙;回弹随着弯模间隙的增大而增大,随芯棒前伸量、镶块间隙、防皱模间隙的增大而减小.同时建立显著性工艺参数与回弹角度的回归预测模型,经对比验证,此模型得到的结果与虚拟正交试验之间的相对误差不超过5％.%Springback can happen after the unloading of numerical control bending of the pipe fitting.In order to improve the forming quality of the bending of ship pipe fitting,the effective control of the springback after bending unloading is needed.Based on the finite element software Dynaform platform,a threedimensional finite element model of numerical control bending and springback ship 20# tube is established,simulating the procedure of the springback after the unloading.Through orthogonal experimental design,the range analysis and the variance analysis of the data of springback angle are carried out and the significance and regularity of technological parameters on springback are studied.The results show that for the springback angle,the sequence of significant technological parameters are as follows:the gap between the anticrease die and pipe,the gap between the bending die and the pipe,the extension of the mandrel and the gap between the insert and the pipe.The springback increases with the increase of the die clearance,and decreases with the increase of the mandrel advance,the gap between the inserts and the gap of the anticrease die.At the same time,the regression prediction model of significant process parameters and springback angle is established.After comparison and verification,the relative error between the model and the virtual orthogonal test is not more than 5 ％.