Crack Resistance of AA6156 Welded Stringer Panels

Abstract

Experimental and numerical analysis of crack growth in integral skin-stringer panels, produced by Laser Beam Welding (LBW), was performed in the scope of WELDAIR project and later on. Experiment was performed on full-scale components (four stringers, three welded clips), made of AA 6156 T6. Digital Image Correlation (DIC) was used to measure strains and construct CTOD or J crack resistance curves. It was shown that J vs. Δa can have unusual shape, indicating real component crack resistance instead of critical J value commonly obtained by comparing J-R curves with calculated Crack Driving Forces (CDFs). The applied technique is simple, practical and has no limitation in respect to material and geometry