Interaction equations for multiaxial fatigue assessment of welded structures
Interaction equations for multiaxial fatigue assessment of welded structures
复制标题
焊接结构多轴疲劳评估的相互作用方程
DOI：
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
G. Marquis
中科院分区：
文献类型：
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作者：
M. Bäckström;G. Marquis
从233个焊接试样从8个不同的研究多轴疲劳数据进行了评估的基础上发表的相互作用方程的正常和剪应力。根据SFS 2378、欧洲规范3和国际焊接学会（IIW）的建议，获得了相互作用方程。法向应力和剪应力的疲劳等级直接从设计指导文件中获得。此外，通过对不同样本类型的仅弯曲和仅扭转数据进行回归分析，确定平均疲劳强度。在某些情况下，不同标准假设的S-N斜率不适用于测试数据。在弯曲和扭转之间表现出显著不同的开裂位置或开裂模式的试样不容易由相互作用方程关联。在法向应力和剪应力都倾向于在同一位置和同一方向产生裂纹萌生和扩展的情况下，相互作用方程的效果最好。IIW推荐的非比例加载的损伤总和为0.5，这与管-板试样的实验观察结果一致。其他代码使用单位伤害总和。
Multiaxial fatigue data from 233 welded test specimens taken from eight different studies have been evaluated based on three published interaction equations for normal and shear stress. The interaction equations were obtained from SFS 2378, Eurocode 3 and International Institute of Welding (IIW) recommendations. Fatigue classes for normal and shear stress were obtained directly from the design guidance documents. Additionally, mean fatigue strengths were determined by regression analysis of bending only and torsion only data for different specimen types. In some cases, the S-N slopes assumed by the different standards were not appropriate for the test data. Specimens that showed significantly different cracking locations or cracking mode between bending and torsion were not easily correlated by the interaction equations. Interaction equations work best in cases where both the normal stress and the shear stress tend to produce crack initiation and growth in the same location and in the same direction. The use of a damage summation of 0.5 for non-proportional loading as recommended by IIW was consistent with experimental observations for tube-to-plate specimens. Other codes used a damage sum of unity.