Improvement of Developed Methodology to Predict the Residual Strength of Composite Structures Damaged by Impact Loading.

Abstract

Composite materials combine a high strength and stiffness with a relatively low density. These materials can, however, exhibit complex types of damage, like transverse cracks and delaminations. These damage scenarios can severely influence the structural performance of a component. Thus, periodic inspections are required to ensure the integrity of a component during its life. The current inspection methods are often time-consuming, costly and require the components to be readily accessible. Therefore, this project aims to improve a methodology based on a combination of different techniques. For this, vibration-based method is used to identify and locate globally the damage. After, optical method (Shearography Speckle) is used to locate locally and estimate the extension of the damage. Finally, a residual strength criterion based on bending loading is used to determine the residual life of the structure. Thus, in order to improve the methodology proposed by the applicant during his doctorate, it will be proposed and evaluated new residual strength criteria considering or not analysis of geometric uncertainties in the computer models and analysis of statistical uncertainties in the experimental results. For evaluating the potential and limitations of this approach, it will be used structural elements made of composite material, such as beams, flat and/or curves plates.