Methodology to analyse aerospace structures repaired with a bonded composite patch

Adhesively bonded composite repair of metallic structures is one of the can didate technologies that has enormous potential in the ageing aircraft. A c omputational tool to analyse the repaired aerospace structure using an adhe sively bonded composite patch is presented. This involves the three-layer t echnique based on the two-dimensional finite element method for adhesively bonded composite patch repair of cracked structures. This technique is capa ble of characterizing the crack growth and debond growth behaviour, as well as predicting the fatigue life extension of the repaired structure with a perfectly or imperfectly bonded patch. Also? the thermal effects which may develop during bonding or during service and the non-linear material behavi our of the adhesive are incorporated in this technique. The results from th e three-layer technique show good agreement with experimental results as we ll as a previous investigator's published numerical results. Besides the ac curacy of the technique, the advantage of the two-dimensional three-layer t echnique is cost-effectiveness when compared with the three-dimensional fin ite element or performing expensive experiments on various patch configurat ions for design purposes. An overview of the three-layer technique to inves tigate a cracked metallic plate repaired with bonded composite patch is pre sented in this paper.