AH36钢焊接接头动态应力应变特性分析

Analysis of dynamic stress-strain characteristics of AH36 steel welded joint

基于热弹塑性法研究了160°对接AH36钢焊接接头动态应力应变过程,同时制作试样,利用三维全场应变测量分析系统记录焊接应变的动态变化,验证了焊接有限元结果的准确性.分析了预热温度和焊接速度对动态应力应变的影响.研究结果表明,随着预热温度的增加,焊接变形逐渐减小.预热温度为200℃时的平均焊接变形量比未预热时的平均焊接变形量降低了34.6%,同时改善了焊接应力场的分布情况,增加焊缝及热影响区的压应力分布区域,但应力幅值对预热温度的改变不敏感.焊接变形随焊接速度增大而增大,当焊接速度大于5 mm/s时,增长趋势逐渐平缓,焊接变形场等势分布面积减小.随着焊接速度的增加,焊接压应力场分布区域减小,焊接拉应力场分布区域增大,焊接速度的改变还会造成平板厚度方向中间层厚度处的应力出现波动.

Based on the thermal elastic-plastic method,the dynamic stress-strain deformation process of AH36 steel welded joint with 160°butt joint was studied.At the same time,the sample was made,and the dynamic change of welding strain was recorded by three-dimensional full-field strain measurement and analysis system,which verified the accuracy of welding finite element results.The effects of preheating temperature and welding velocity on dynamic stress and strain were analyzed.The results show that with the increase of preheating temperature,the welding deformation decreases gradually.When the preheating temperature is 200℃,the average welding deformation is reduced by 34.6%compared with the average welding deformation without preheating.At the same time,the distribution of welding stress field is improved,and the compressive stress distribution area of weld and heat affected zone is increased,but the stress amplitude is not sensitive to the change of preheating temperature.The welding deformation increases with the increase of welding velocity.When the welding velocity is greater than 5 mm/s,the growth trend gradually slows down,and the equipotential distribution area of the welding deformation field decreases.With the increase of welding velocity,the distribution area of welding compressive stress field decreases,and the distribution area of welding tensile stress field increases.The change of welding velocity will also cause the stress of middle layer thickness to fluctuate.