Influence of residual stresses on fatigue strength of large-scale welded assembly joints
Influence of residual stresses on fatigue strength of large-scale welded assembly joints
复制标题
DOI：
10.1007/s40194-016-0407-8
复制
发表时间：
2017-03
影响因子：
2.1
通讯作者：
J. Klassen;N. Friedrich;W. Fricke;T. Nitschke–Pagel;K. Dilger
中科院分区：
文献类型：
--
作者：
J. Klassen;N. Friedrich;W. Fricke;T. Nitschke–Pagel;K. Dilger
已知残余应力（RS）以某种方式影响焊接结构的疲劳强度。这些残余应力的大小取决于热输入、焊缝存款的体积、每个焊缝的焊道数和相邻焊缝的数目。因此，残余应力状态已经在设计状态中引起了人们的兴趣。然而，通过测量进行确定的可能性是有限的且昂贵的。数值焊接模拟可能会有所帮助。然而，焊接数值模拟仍然是一个具有挑战性的任务，特别是在大规模建模和多道焊，要求简化的方法和模型。即使人们能够计算残余应力，它们对大型焊接结构疲劳强度的影响仍然是不确定的。在疲劳评估过程中，通常假设存在高达材料屈服强度的拉伸残余应力。另一方面，已知残余应力在循环加载期间重新分布，从而减少其对疲劳的影响。在这项工作中，大规模的组件的实验和数值研究。进行疲劳试验，并确定在不同的状态下，循环加载之前和期间的残余应力（X射线）。计算结果与实测结果进行了比较。讨论了残余应力循环再分布对疲劳强度的影响。本文代表了最近完成的一个研究项目的一些最有意义的结果。有关这项工作的更多详细信息和结果，请参见Dilger等人的报告（AiF-Schlussbericht，IGF-Vorhabennummer 17652 N，2016）。
Residual stresses (RS) are known to affect fatigue strength of welded structures in some way. The amount of these residual stresses depends on heat input, the volume of the weld deposit, the number of passes in each weld, and the number of adjacent welds. Therefore, residual stress states are of interest in the design state already. However, determination possibilities by measuring are limited and costly. Numerical welding simulation might be helpful. However, numerical welding simulation still is a challenging task, especially in large-scale modeling and multi-pass welding, calling for simplified methods and models. Even if one is able to calculate residual stresses, their effect on fatigue strength of large-scale welded structures remains uncertain. During fatigue assessment, it is often assumed that tensile residual stresses up to yield strength of the material are present. On the other hand, it is known that residual stresses are redistributed during cyclic loading, thus reducing their effect on fatigue. In this work, experimental and numerical investigations on large-scale components are presented. Fatigue tests were performed and residual stresses (X-ray) were determined at different states, before and during cyclic loading. Calculated and measured results are compared. The influence of residual stresses on fatigue strength with respect to cyclic redistribution is discussed. This paper represents some of the most meaningful results of a recently finished research project. Further information and results in more detail of this work can be found in the report of Dilger et al. (AiF-Schlussbericht, IGF-Vorhabennummer 17652N, 2016).