Effect of weld size on fatigue crack growth behaviour of cruciform joints by strain energy density factor approach

The effect of weld size on fatigue crack growth behaviour of cruciform joints containing lack of penetration defect has been analysed by using the strain energy density factor concept. Load carrying cruciform joints were fabricated from ASTM 517‘F' grade steel. Fatigue crack growth experiments were carried out in a mechanical resonance vertical pulsator (SCHENCK 200 kN capacity) with a frequency of 30 Hz under constant amplitude loading (R=0). It was found that the crack growth rates were relatively lower in the larger welds fabricated by multipass welding technique than the smaller welds fabricated by the single pass welding technique.