A finite element analysis involving three-layers of two-dimensional Mindilin plate elements, to model cracked plate, adhesive, and composite patch, was developed to characterize fatigue crack growth behavor of a the metallic panel repaired with an adhesively bonded composite path. Also, fatigue experiments were conducted with 6.35 mm thick specimens with a pre-crack repaired asymmetrically with adhesively bonded unidirectional boron/epoxy patch. Fatigue crack growth rates on the unlatched and patched faces (PF) were measured along with debound of the composite patch. Stress intensity factors obtained from the analysis were combined with the fatigue crack growth relationship for heunrepaired cracked material to obtain the analytical fatigue crack growth rates. The experimental and analytical fatigue crack growth rates on the unpatched face (UPF) were in a good agreement with each other when the proposer consideration of the effective crack length and debond were incorporated in the analysis. Thus, the three-layer technique was found to be capable of characterizing the fatigue crack growth behavior of the repaired thick panels as in the case of repaired thin panels shown in the previous studies.
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