Finite element and analytical analysis of cracks in thick stiffened plates repaired with a single–sided composite patch

Abstract

The purpose of this thesis was to investigate crack growth behavior in thick stiffened aluminum plates repaired with a single-sided composite patch. A model was developed using finite element analysis that extracted the mode I strain energy release rate (SERR) with use of the Virtual Crack Closure Technique. The dimensions and spacing of the stiffeners were varied to determine their effect on reducing the SERR. This model was also compared to an unstiffened model and one without a composite patch. A tensile load and a bending moment were both applied to the model for various configurations. These results were then used to develop an analytical model that can be used to predict the effectiveness of a patched surface.