Investigation of laser beam welded aluminium alloy joints in terms of strength and fracture mechanics

In this study, stress distribution around the crack tip and elastic plastic fracture toughness parameters of laser welded 6013 aluminum alloy, commonly used in the aerospace industry having two different thicknesses is investigated.For this purpose, compact tension (C(T)-50) specimens used in the experimental analysis with 6 and 3,2 mm thicknesses are modeled using the finite element software. As a result of the analyses, the stress distribution around the crack tip, CTOD, delta 5 (Crack Tip Opening Displacement) and J-integral values are determined and CTOD, delta 5-delta a and J-?a resistance curves are created. CTOD, delta 5-delta a resistance curves are compared with those obtained from the experimental work and J-delta a resistance curves are compared with those obtained from formulation. The effect of strength mismatch on resistance curves are determined. Delta plastic hinge values obtained by the plastic hinge method are compared with CTOD, delta 5 values. It has been concluded that the maximum stress obtained at the crack tip has occured in the base material, fracture toughness parameters obtained from the finite element analysis showed a good agreement with those obtained by the experimental work and formulation and the resistance curves obtained by using the CTOD and J-integral characterize the resistance of the material against crack growth in a similar manner.