Evaluation of sensitivity for detecting different failure modes of epoxy matrix composites doped with graphene nanoparticles

Abstract

In recent years, the interest in monitoring the damage of composite materials by measuring the variation of electrical resistance is increasing because deformations and cracks generated in the structure produce changes in the electrical conductivity of the material. In this work, the structural integrity of glass fiber composite materials with epoxy matrix doped with graphene nanoparticles is evaluated under in plane tests (interlaminar shear tests and fracture propagation tests in mode I and II). The results demonstrated the ability of graphene nanoparticles to form conductive networks in the epoxy resin with auto-detection capability of deformation and damage. In the interlaminar shear tests, permanent changes in resistance were associated to strain and delamination produced during the test. In the case of fracture tests in mode I and II, the electrical resistance increased as the crack grew. The use of multiple electrodes has also allowed locating the area of damage generation in the material. Finally, the electrical response of discontinuities generated out of plane of the laminate was analyzed by means of cuts through the material.