2023 Volume 41 Issue 1 Pages 36-41
It is natural to see the edge of the nugget in spot weld joint as a sharp notch or a crack. In this sense, the driving force for fatigue crack growth can be estimated using fracture parameter such as the range of stress intensity factor ΔK. In this research, Equivalent Stress Intensity Factor Range ΔKeq defined through integration of stress field is employed as a parameter. The primary advantage of ΔKeq is its simplicity in computation. It is known that fatigue strengths of spot welded joints are influenced by various factors, such as plate thickness, nugget diameter, number of spot welds and their arrangement, geometry of welded component, combined loading condition and welding residual stress. The effects of these factors can be estimated in a consistent manner using the proposed method which is based on ΔKeq and the master curve identified from experimental data. Its potential usefulness for fatigue design is demonstrated through typical examples.
