SELECTION OF THE DESIGN PARAMETERS IN LAMINATE REPAIR

Laminate repair is a basic research topic of composite repair. Thereinto, patch-bonded repair and flush repair are the two most important methods. In this work, FEM analysis was researched on the above two methods, and the scheme of parameter selection was provided. The research shows that, for most patch-bonded cases, patch thickness should be half of the original laminate, and the overlap length should be about 25 mm. And for most flush repairs, the scarf angle can be 6°. Typical specimens were tested to verify the optimized design parameters. To eliminate the influence of the additional bending and to simulate the actual structure more exactly, the patch-bonded specimens should be designed as two-sided repair. The results of the tests fitted in well with the parameters derived from the theoretical analysis. And the scheme of parameter selection has great significance in directing the engineering practice of composite repair.