Optimization of fibre coating properties for fiber optic smart structures

Actuators and/or sensors embedded into a host material will disrupt the physical properties of the host. Finite element analysis was used to determine and to minimize the stress concentrations which arise in a 'smart' material system due to the embedded optical fibre sensor. A parametric study was undertaken to determine the theoretical mechanical and thermal properties of the interface coating that minimize the disruption of the properties of the polymer composite host material due to the optical fibre inclusion. The effects of transverse tensile and thermal loading were studied, and also the residual thermal stress concentrations due to the manufacturing process were taken into consideration. The stress concentrations in the composite host are affected by the dimensions, mechanical and thermal properties of the interface coating. The results show that with careful selection of the interface coating properties the stress concentrations in the host material caused by the optical fibre inclusion can be reduced and be similar to those of the pure host material.