冷拔无缝钢管残余应力测量的杂交实验方法

提出了一种数值模拟和实验杂交的实验方法,测量了钢管内表面的残余应力。采用非线性有限元法模拟了冷拔钢管的成型过程,得到了钢管脱模以后的残余应力,通过释放切口处单元的刚度模拟了含有残余应力钢管的切割过程,研究了切割方法对残余应力的影响,数值计算和实验结果表明切割方法对二次残余应力有很大影响。采用X射线测量仪测量了钢管内表面的残余应力。研究结果表明,计算结果基本符合实验结果,误差可以被工程接受。

A Hybrid Experiment Method for Residual Stress Measurement inside of Seamless Tube

A hybrid experiment method combined numerical modeling and experiment is developed,the second residual stresses in the inside of the tube were measured.The processes of the cold drawing tube were analyzed by the nonlinear finite element method with consideration of elastic-plastic,large deformation and nonlinear contact,and the residual stresses after drawing were got.The second residual stresses were obtained by modeling the processes of cutting tube with the technology of releasing the stiffness of the elements located at the cuts.Parameter study shows that the distribution of second stresses got from cuts in the direction of axis is different from that in the direction of section.The cutting method and the location selected for measurement are based on numerical modeling.The second stresses were also measured by the instrument of X ray.The results show that the results from numerical modeling agree with the data from experiments.