Spot weld arrangement effects on the fatigue behavior of multi-spot welded joints

In the present study, the effects of spot weld arrangements in multi-spot welded joints on the fatigue behavior of the joints are studied. Three different four-spot welded joints are considered: one-row four-spot parallel to the loading direction, one-row four-spot perpendicular to the loading direction and two-row four-spot weld specimens. The experimental fatigue test results reveal that the differences between the fatigue lives of three spot welded types in the low cycle regime are more considerable than those in the high cycle regime. However, all kinds of spot weld specimens have similar fatigue strength when approaching a million cycles. A non-linear finite element analysis is performed to obtain the relative stress gradients, effective distances and notch strength reduction factors based on the volumetric approach. The work here shows that the volumetric approach does a very good job in predicting the fatigue life of the multi-spot welded joints.

[1]  Sankaran Mahadevan,et al.  Probabilistic fatigue crack growth analysis of spot-welded joints , 2004 .

[2]  Byoung-Ho Choi,et al.  Observation and prediction of fatigue behavior of spot welded joints with triple thin steel plates under tensile-shear loading , 2007 .

[3]  Shicheng Zhang,et al.  Stress Intensities at Spot Welds , 1997 .

[4]  H Adib,et al.  Theoretical and numerical aspects of the volumetric approach for fatigue life prediction in notched components , 2003 .

[5]  D. Du,et al.  Finite element analysis of effect of electrode pitting in resistance spot welding of aluminium alloy , 2005 .

[6]  Ning Pan,et al.  Spot welds fatigue life prediction with cyclic strain range , 2002 .

[7]  K. Tohgo,et al.  The Prediction of Fatigue Crack Initiation Life in Spot Welds , 2009 .

[8]  G. Pluvinage.  Fracture and Fatigue Emanating from Stress Concentrators , 2003 .

[9]  Ne Dowling,et al.  A CRACK GROWTH APPROACH TO LIFE PREDICTION OF SPOT‐WELDED LAP JOINTS , 1998 .

[10]  J. Gilgert,et al.  Fatigue life duration prediction for welded spots by volumetric method , 2004 .

[11]  Yuh J. Chao,et al.  Ultimate Strength and Failure Mechanism of Resistance Spot Weld Subjected to Tensile, Shear, or Combined Tensile/Shear Loads , 2003 .

[12]  Hong Tae Kang.  Fatigue prediction of spot welded joints using equivalent structural stress , 2007 .

[13]  K. Tohgo,et al.  Influence of Strength Level of Steels on Fatigue Strength and Fatigue Fracture Mechanism of Spot Welded Joints , 2006 .

[14]  Sung-Jin Song,et al.  A fatigue design method for spot-welded lap joints , 2002 .

[15]  J. Kucza,et al.  Static and Fatigue Behavior of Spot-Welded 5182-0 Aluminum Alloy Sheet , 1999 .

[16]  Ruijie Wang,et al.  Low-cycle fatigue life prediction of spot welds based on hardness distribution and finite element analysis , 2009 .