Chapter 5 - Disbond and damage tolerance analysis of doubler repairs

Abstract

In this chapter, various analytical methods for disbond and damage tolerance analysis of doubler repairs under both static and fatigue loads are delineated. They range from closed-form to finite element (FE)-based methods. Most closed-form methods are relatively simple and can be easily implemented into practical design and analysis tools. In contrast, most FE-based methods are either already available in popular commercial FE codes such as the cohesive zone model or they can be performed manually outside of the FE calculations using standard FE outputs via simple formulas such as the virtual crack closure method. A brief review of the fatigue damage accumulation model widely used in the safe-life certification approach is also presented.