Potentials of guided waves in Aircraft CFRP components in terms of damage tolerance and SHM Implementation

Abstract

Carbon fibre reinforced polymer (CFRP) materials are a class of materials becoming possibly the most important in aeronautical structures today. Due to its relative novelty neither its damage mechanisms nor its potentials are far from being sufficiently understood. As a consequence CFRP when compared to metallic structures are still designed safe life. Damage could in CFRP structures be more efficiently monitored. Then damage tolerance potentials even in CFRP structures could be considered. Guided waves are a means on how a significant amount of CFRP structures could be monitored in principle since many of those structural components are flat plate like. Typical joints are lapped or tapered such as with structural repairs, which are structural elements of a specific criticality. This thesis will address the following aspects and questions related to CFRP plate structures: 1. What are guided waves? 2. Material parameters in a CFRP panel relevant for structural design to be obtained through non-destructive testing. 3. Limitations of guided waves with respect to a lap joint. 4. Monitoring concepts of a lap joint in terms of structural health monitoring (SHM). 5. What damages may be monitored with the SHM concept proposed?