The Study of Local Stress Intensity Factors for Kinked (and Branched) Cracks in Commonly Used Spot Weld Specimens
Journal Article
05-12-03-0015
ISSN: 1946-3979, e-ISSN: 1946-3987
Sector:
Topic:
Citation:
Lin, Z., Wang, D., Chee, C., and Lin, P., "The Study of Local Stress Intensity Factors for Kinked (and Branched) Cracks in Commonly Used Spot Weld Specimens," SAE Int. J. Mater. Manf. 12(3):197-220, 2019, https://doi.org/10.4271/05-12-03-0015.
Language:
English
Abstract:
Local stress intensity factors (LSIFs) for kinked (and branched) cracks of spot
welds in lap-shear (LS), cross-tension (CT), U-shaped (US), and coach-peel (CP)
specimens were investigated by three-dimensional (3D) finite element analyses
(FEA). Models of spot welds without and with kinked (and branched) cracks were
developed to derive global SIF (GSIF) and LSIF, respectively. Kinked (and
branched) cracks with semielliptical shapes were assumed. Two dominant cracking
modes were considered for each specimen. Note that fine mesh size and reasonable
mesh design for crack tip regions were adopted to improve the computation
accuracy. GSIFs for main crack were obtained to derive local SIFs for
infinitesimal kinked cracks. LSIFs for finite kinked (and branched) cracks were
then obtained. The computational results show that the LSIF solutions of the
four specimens have similar general trends. As kinked (and branched) crack
length increases, mode I LSIF solutions gradually increase and then decrease,
while mode II LSIF solutions show inverse trends. Finally, applications of local
SIFs for fatigue life estimations of spot welds were discussed.