Fracture behavior of welded mis-matched joints

In this study, laser beam welded Aluminum Alloy 6056 plates have been used to obtain the crack resistance curves (R-curves) in Compact Tension C(T) specimens. Laser beam welding is a noval joining method used for hard to join materials, such as aluminum alloys, which were considered unweldable formerly. Defect free welds have been obtained with Nd: YAG type laser. Three types of C(T) specimens have been employed for this study, namely, Base Metal (BM), welded specimen with crack in the Weld Metal (WM) and welded specimen with crack in the Heat Affected Zone (HAZ). Fracture mechanics test have been carried out in order to determine the Crack Tip Opening Displacement (CTOD), Crack Mouth Opening Displacement (CMOD) and crack extension (Da) values corresponding to the applied load. ABAQUS software has been utilized to carry out the numerical analysis. The input parameters were the applied load and the crack length. The output parameters were CTOD, CMOD and J-Integral. Experimental and numerical results have been compared with various graphics, it can be concluded that they are in good agreement for all conditions.