Self-sensing structural composites in aerospace engineering

Abstract

Abstract Self-sensing structural composite materials refer to structural materials that can sense their own condition (strain, stress, damage and temperature), without embedded or attached sensors. Self-sensing based on electrical resistance measurement is effective in continuous carbon fibre polymer matrix composites, which are important for aerospace structures. This effectiveness stems from the electrical conductivity of the carbon fibres and the consequent effect of the composite microstructure on the electrical resistivity of the composite. The volume, surface region and interlaminar interface of a carbon fibre composite laminate are all associated with electrical resistance, which serves to indicate the condition of the laminate. By using an array of electrical contacts, spatially distributed sensing is achieved. The strain and stress can be in the longitudinal (in-plane) direction, through-thickness direction or other directions of a laminate. In addition, the joint interface of a fastened joint between two laminates is associated with electrical resistance, which serves to indicate the condition of the joint.