Optimisation of optical fibre using micro-braiding for structural health monitoring

Structural health monitoring is a fast growing area used to assess the state of various structures such as aircraft, building, bridge, wind turbine, pipe, automobile through appropriate data processing and interpretation. This article presents a novel technique of optimising the conventional optical fibres used for structural health monitoring, in order to improve their mechanical properties, and handling during the manufacturing process by micro-braiding the optical fibres. This study investigates and compares the tensile properties of the both micro-braided optical fibre and conventional optical fibres through uniaxial tensile tests. Experimental results show 85% improvement in strain at failure for the micro-braided optical fibre when compared to the optical fibres. Moreover, interfacial shear strength comparison, of the braiding yarn, between optical fibres and micro-braided optical fibre (carried out through micro-bond test) has also been conducted. In addition, the effect of embedding both micro-braided and conventional optical fibre in composite was also investigated by three-point bend test. Overall, the mechanical performance of the composite was not affected by the presence of micro-braided optical fibre. This article will also discuss the process and the advantage of micro-braided optical fibre for structural health monitoring.