Structural health monitoring of an asymmetrical SMA reinforced composite using embedded FBG sensors

Embedded actuator and sensor technology provides accurate structural health monitoring and proper structural response of a structure in any harsh servicing situation. This paper describes the fabrication of a smart composite by embedding shape memory alloy (SMA) wires and fibre Bragg grating (FBG) sensors into a glass fabric reinforced polymeric composite. Mechanical performances of the composite under martensitic and austenitic stages of the SMA wires were studied, and its natural frequencies were also measured accordingly. The result shows that the shift of the natural frequency arises from temperature change, thus changing the mechanical properties of the SMA wires. The changes of strain, stress, curvature, and damping ratio were predicted from an asymmetrical lamination model. It was found that this model demonstrates certain attractive effects, including mechanical properties, the change of shape, and the natural frequency upon activation of the SMA wires.