Combined effect of strength & sheet thickness on fatigue behaviour of resistance spot welded joint

• Published in: Fatigue & fracture of engineering materials & structures Vol. 33; no. 9; pp. 562 - 574
• Main Authors: GHOSH, S., PAL, T. K.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.09.2010; Blackwell; Wiley Subscription Services, Inc
• Subjects: Applied sciences; Automotive components; Exact sciences and technology; experimental & predicted fatigue life; Fatigue; Fatigue failure; Fatigue life; Fracture mechanics; fracture micro-mechanisms; Fractures; Joining, thermal cutting: metallurgical aspects; Materials fatigue; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; resistance spot weld; Shear; Sheet metal; sheet thickness & strength; Steel; Steels; Strength; Stress intensity factors; Welding; Fatigue life; Rupture; Resistance spot welding; Mechanical properties; Fatigue; Mechanism; Thickness; Welded joint; experimental & predicted fatigue life; Fatigue strength; Sheet metal; Spot welding; resistance spot weld; fracture micro-mechanisms; sheet thickness & strength; Strength
• ISSN: 8756-758X; 1460-2695
• DOI: 10.1111/j.1460-2695.2010.01467.x

ABSTRACT Fatigue performance of spot welded lap shear joint is primarily dependent on weld nugget size, sheet thickness and corresponding joint stiffness. Two automotive steel sheets having higher strength lower thickness and lower strength higher thickness are resistance spot welded with established optimum welding condition. The tensile‐shear strength and fatigue strength of lap shear joint of the two automotive steel sheets are determined and compared. Experimental fatigue life of spot welded lap shear joint of each steel are compared with predicted fatigue lives using different stress intensity factor solutions for kinked crack and spot weld available in literature. Micrographs of fatigue fractured surfaces are examined to understand fracture micro‐mechanisms.