Stiffness Analysis of Steel Plate with a Rectangular Cut out Bonded by Composite Patch

Based on the features of steel plate with a rectangular cut out bonded by composite patch, a three-dimensional mechanical model for stiffness analysis was developed. The relative stiffness of steel plate with a rectangular cutout before and after bonded composite patches versus intact plate is introduced and investigated. The results indicate that the relative stiffness of the patched plate increases with the patch thickness increasing, but the performance can not be effectively improved depending upon adding patch thickness alone, when patch thickness is more than five layers. The analytical solutions, when patch more than the 4 layers, are in good agreement with the finite element simulations.