Numerical Evaluation of Mode II Disbonding on Fiberglass CCPs-Specimens and Material Characterization Utilizing a Distributed Sensing Rayleigh Backscattering System

Nowadays, composite materials have become the main construction materials for aeronautical structures, replacing traditional materials commonly used in this industry. However, composite structures are still characterized by conservative designs due to the lack of understanding from a physics-based approach their damage propagation and failure mechanisms. Since repairs of composite structures are a crucial part of the long-term use of composites in aerospace, the stakeholders require an in depth understanding of the physics of disbonding in composites. The aim of this research is a numerical evaluation of mode II disbonding on Center Cut Plies (CCPs) specimens with a preliminary study on material characterization performed through a Distributed Sensing System (DSS). In order to fulfill the objectives of this research, CCPs specimens manufactured from unidirectional fiber prepregs will be considered. The specimens will be produced from unidirectional prepregs in order to minimize the effects of residual stress fields introduced into the specimen during the curing process. That residual stress field will be evaluated and monitored making use of a Distributed Sensing System (DSS) optical fiber mounted and embedded within the laminas of the specimen. In addition, an analytical and numerical approach through FEM analysis will be adopted and validated to verify the experimental results obtained from the DSS.