Design and validation of composite patch repairs to cracked metallic structures

This paper describes an approach to a patch design for a crack repair, based largely on the simple closed-form analyses. For simplicity, the design approach does not include the effect of the out-of-plane bending nor polygon-shaped patch. However, once the basic design was brought out by that design approach, it can be re-analysed by using other advanced analytical models to account for those latter complexities. These advanced analytical methods are therefore also reviewed briefly in the paper. In addition, test data to validate the mentioned design and analysis methods are also presented and discussed.