The effect of angular distortion on the fatigue behavior of
non-penetrating laser welded lap specimens of 301LN stainless steel
- Xiangzhong Guo,
- Wei Liu,
- Xiqing Li,
- Zhikun Song
Abstract
In this work, the fatigue behaviors of non-penetrating laser welded lap
specimens of cold-rolled 301LN austenitic stainless steel were
investigated based on experiments and numerical analyses. The
experiments showed the unequal-thickness specimens failed in the thicker
bottom sheet under low fatigue loads, even though the mean stress in the
thinner top sheet was higher, when the applied loads were high enough,
the failure location changed from the bottom sheet to the top sheet.
This phenomenon could be successfully explained through traction stress
analysis considering the effect of angular distortion. However, the
equivalent traction stress representation of fatigue data is below the
ASME master S-N curve scatter band since the stress exceeds the yield
limit of the base metal at low-cycle fatigue regime. The structural
strain approach was then used to consider the effect of plastic
deformation, and all fatigue data fall into ASME master E-N curve
scatter band. This indicates the structural strain approach in
conjunction with the master E-N curve is suitable for correlating both
low- and high-cycle fatigue data of the non-penetrating laser welded lap
specimens.