Numerical and experimental description of the welding residual stress field in tubular joints for fatigue assessment
Numerical and experimental description of the welding residual stress field in tubular joints for fatigue assessment
复制标题
用于疲劳评估的管接头焊接残余应力场的数值和实验描述
作者：
Kimiya Hemmesi;M. Farajian;D. Siegele
为了实现焊接结构的抗疲劳，有必要对影响焊接结构疲劳强度的焊接工艺相关因素进行管理和控制。这些因素有时表现为焊接缺陷，有时表现为焊接过程中不可避免的残余应力。自20世纪50年代以来，焊接研究界一直在研究这个问题。然而，这种影响的程度尚不清楚，目前仍存在争议。拥有先进的准确测定焊接残余应力的预测工具，不仅可以在寿命估计中考虑精确的焊接残余应力影响，而且可以为后续焊接残余应力场的缓解或修改提供有效的措施。本研究的目的是通过两种不同的案例来描述S355J2H结构钢焊接管接头的焊接残余应力场。用x射线、同步加速器和中子衍射技术测定了带假焊缝（案例1）和管焊缝上焊头（案例2）的圆柱形试样的残余应力。利用SYSWELD软件对焊接残余应力进行数值计算，综合考虑冶金相变效应，计算材料微观组织与残余应力之间的关系。热学和冶金计算通过考虑熔合/凝固潜热和瞬态热传导方程的转换，将温度场和相比耦合起来。得到的结果，包括热和冶金历史被用作输入数据的机械计算之后。通过温度分布和残余应力实验验证了热模型和结构模型的准确性。
In order to achieve fatigue resistant welded structures, it is necessary to manage and control welding process-related factors which affect the fatigue strength. These factors are sometimes present as welding defects and sometimes as inevitable residual stresses which are unwanted by-products of welding processes. This subject has been treated in welding research communities since the 1950s. However, the extent of this effect was unclear and is still a matter of debate. Having advanced predictive tools for accurate determining welding residual stresses will not only lead to the possibility of considering precise welding residual stress effects during life estimation but also can be useful to have effective measures for the subsequent mitigation or modification of the welding residual stress fields.The objective of this study is to describe experimentally and numerically the welding residual stress field in welded tubular joints made of structural steel S355J2H in terms of two different case studies. Residual stresses in cylindrical specimens with dummy welds (case-1) and bead on tube welds (case-2) are determined experimentally by means of x-ray, synchrotron, and neutron diffraction techniques. The SYSWELD software is used to calculate the welding residual stresses numerically by integrating the metallurgical transformation effects in order to compute the link between material microstructure and residual stresses. Thermal and metallurgical calculations couple the temperature field and phase proportions by considering the latent heat of fusion/solidification and the transformations in the transient heat conduction equation. Obtained results which include both thermal and metallurgical history are used as input data for mechanical calculations afterward. The accuracy of the both thermal and structural models is validated through experiments for temperature distribution and residual stresses.
多轴载荷下管状钢接头的焊接残余应力行为*
DOI：
10.3139/105.110208
发表时间：
2014
期刊：
HTM Journal of Heat Treatment and Materials
影响因子：
--
作者：
M. Farajian;Th. Nitschke-Pagel;D. Siegle
通讯作者：
D. Siegle