Sensors for process and structural health monitoring of aerospace composites: A review

Structural Health Monitoring (SHM)is a promising approach to overcome the unpredictable failure behaviour of composite materials and further foster their use in aerospace industry with increased confidence. SHM may require a complex system, including sensors, wiring and cabling, data acquisition devices and software, data storage equipment, power equipment and algorithms for signal processing, involving a multidisciplinary team for its adequate development considering the operational environment and requirements of a certain application. This review paper focuses on the most promising type of sensors, laboratory made and commercially available, for SHM of aerospace composites. Sensing principles, characteristics, embedding procedures, sensor/ host materials interactions and acquired sensor data/ material behaviour are discussed. The use of sensors for in-situ process monitoring, specifically for curing and mould filling monitoring in liquid composite moulding processes are discussed. General considerations for the development of SHM systems for the aerospace environment are also briefly mentioned.