Fatigue prediction of spot welded joints using equivalent structural stress

The author proposes a fatigue prediction method for spot welded joints in automotive body structures using an equivalent structural stress at the edge of spot welds. The proposed fatigue prediction method is developed by substituting the stress components in von Mises equation to the local structural stresses at the vicinity of spot weld. The structural stresses at the edges of the weld nugget in each sheet are calculated using the forces and moments that are determined by finite element analysis. The equivalent structural stresses are correlated to experimental fatigue data to predict fatigue life of the spot welded joints. The proposed method is evaluated with two different experimental fatigue data of spot welds and shown good correlation with fatigue test results.

[1]  Dieter Radaj,et al.  Stress intensity factors for spot welds between plates of dissimilar materials , 1992 .

[2]  Jwo Pan,et al.  An effective fatigue driving stress for failure prediction of spot welds under cyclic combined loading conditions , 2003 .

[3]  Andreas Rupp,et al.  Computer Aided Dimensioning of Spot-Welded Automotive Structures , 1995 .

[5]  F. V. Lawrence,et al.  A FATIGUE DESIGN PARAMETER FOR SPOT WELDS , 1994 .

[6]  Yung-Li Lee,et al.  Failure modes of single resistance spot welded joints subjected to combined fatigue loading , 2001 .

[7]  Sd Sheppard.  Estimation of Fatigue Propagation Life in Resistance Spot Welds , 1993 .

[8]  Fv Lawrence,et al.  Electric-Potential-Drop Studies of Fatigue Crack Development in Tensile-Shear Spot Welds , 1992 .

[9]  Sheri Sheppard.  Further Refinement of a Methodology for Fatigue Life Estimation in Resistance Spot Weld Connections , 1996 .

[10]  Dieter Radaj,et al.  Stress intensity factors for spot welds between plates of unequal thickness , 1991 .

[11]  Shicheng Zhang,et al.  Fracture mechanics solutions to spot welds , 2001 .

[12]  Yuichi Yoshida,et al.  A New Method of Stress Calculation in Spot Welded Joint and Its Application to Fatigue Life Prediction of Actual Vehicle , 2003 .

[13]  Hong Tae Kang,et al.  Fatigue life estimation of spot welded joints using an interpolation/extrapolation technique , 1999 .

[14]  Dieter Radaj,et al.  Simplified formulae for stress intensity factors of spot welds , 1991 .