Experimental Investigation of Foreign Object Impact on Polymer-Based Composites Used in Aircraft Structures

This paper investigates the impact of foreign object damage on the damage morphology of polymer-based composite structures used in aircraft manufacture. Specimen made from E-glass laminates with epoxy matrix was subjected to quasi-static loading while acoustic emission, as well as scanning electron microscopy, were used to characterize the damage sequence. The study finds that the load-bearing capacity of the specimen impacted by the square indenter is five times more than that for the conical indenter (2.4 KN and 0.48 KN) respectively while the samples subjected to conical indenter absorbed only 13% of the energy of the samples subjected to the blunt indenter before fracture (7.9 J and 1.3 J) respectively. Furthermore, the use of acoustic emission provided a veritable measure for assessing the internal damage mechanism for structural optimization. The major failure modes identified are fibre breakage, matric crack, and delamination.