Fatigue life prediction using two stage model for AISI 304L cruciform joints, with different fillet geometry, failing at toe

Reports in the literature indicate that the fillet geometry affects the fatigue properties of cruciform welded joints in structural steels. In an attempt to study the above effect with respect to stainless steel sheet metal welded joints, load carrying transverse fillet welded cruciform joints having a two fillet geometry were fabricated from AISI 304L stainless steel using gas tungsten arc welding and gas metal arc welding with 308L electrodes. The objective of the present work is to predict the fatigue life of AISI 304L cruciform joints failing at the weld toe using a two stage model. The local stress life method was applied to calculate the fatigue crack initiation life, whereas the fatigue crack propagation life was estimated using fracture mechanics concepts. Constant amplitude fatigue tests with stress ratio R ∼ 0 were carried out using a 100 kN servohydraulic Dartec universal testing machine at a frequency of 30 Hz. An automatic crack monitoring system based on crack propagation gauges was used to obtain the propagation data during the fatigue process. The predicted lives were compared with the experimental values.