ABSTRACT
In this paper, fracture analyses and fatigue crack growth of repaired aluminum panels in mixed-mode conditions using adhesively bonded composite patches are studied. The effects of different patch layup configurations on the fracture parameters and fatigue life of single-sided repaired panels in mixedmode conditions are investigated using both mid-plane and un-patched surface stresses at the crack-tip. It will be shown that the best patch layers angle to prevent the crack propagation is 105° for a repaired panel with inclined crack angle of β=45º except for those materials which they have low KIIC value. There are not significant differences for the obtained crack trajectories, fracture parameters and fatigue life between the repaired panels with various patch lay-up configuration which their first and second layers angles are 90°. There is also a considerable difference of about 20% between the obtained crack propagation paths using mid-plane and un-patched fracture parameters.
