The Effect of residual stress for fracture behavior in the laser weldment

레이저용접부의 파괴에 미치는 잔류응력의 영향

  • 조성규 (전남대학교 대학원 기계공학과) ;
  • 양영수 (전남대학교 기계시스템공학부)
  • Published : 2006.06.02

Abstract

The integrity of laser welded structures is decided with fracture strength and fatigue strength. This study presents fracture behavior considering residual stress in the laser welding. Experiments are conducted and analyses are performed to explore the influence of residual stress on fracture behavior of bead-on laser welded compact specimen. Fracture experiments are performed using ASTM 1820. The performed analyses included thermo-elasto-plastic analyses for residual stress and subsequent J-integral calculation. A modified J integral is calculated in the presence of residual stresses. The J-integral is path-independent for combination of residual stress field and stress due to mechanical loading. The results indicates that the tensile residual stress near crack front bring the low fracture load while the compressive residual stress bring the high fracture load compared to no residual stress specimen. These results quantitatively understand the influence of residual stress on fracture behavior.

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