Damage detection is crucial for high strength to weight ratio fibre-reinforced composites; as they are the structural materials for aerospace structures. Such composite structures degrade at harsh environmental conditions, impact, and abrasion. Damaged composite causes safety, cost, and operational effectiveness problems. Therefore, the structural health of the body must be monitored. Conventional methods can not offer enough warning before failure of the material. Because fatigue life cannot be predicted for high-performance composites by measurements of crack length and propagation data.
Defence agencies give great importance to the material state awareness and remaining service life prognosis. For defence applications detection and remediation of damage at an early stage are vital. Several nondestructive evaluation (NDE) methods have been applied. Commonly, Metal strain sensing by foil strain gauges and optical fibre sensors have been used as damage detection technique. Metal foil strain gauges have limitations. Metal foils can only be mounted to the surface and have a deficient gauge factor. To overcome those drawbacks; optical fibre is embedded in the composite material. However, the application and data acquisition for such an approach costs a lot. Also, embedded optical fibre inside composite cannot detect crack formation and propagation.
At Belpico, we are developing smart composites branded as ANONA. ANONA detects damage by cost-effective, and susceptible carbon nanotube strain sensing technology. By measuring the resistivity of the composite, early stage of damage can be identified. Thus, ANONA can thoroughly scan the fatigue damage in the composite and inform the maintenance crew ahead of time.