Dual-sinusoidal placement of fibre-optic sensors for fine SHM of composite structures

The integration of permanent distributed fibre-optic sensors (FOSs) into large-scale composite structures enables real-time remote monitoring of their internal health conditions. To address the drawbacks in employing embedded FOSs for accurate structural health monitoring (SHM), a new concept of dual sinusoidal placement has been proposed to maximise monitoring coverage whilst minimising sensor count. Despite existing research, further simulation and testing are necessary to fully characterise the mechanical and sensing behaviour of the constructed smart composites across diverse loading conditions. Therefore, this work focuses on studying the strain patterns and sensing advantages resulting from a dual-sinusoidal placement of FOSs in fibre reinforced composites. A detailed finite element modelling of coupon-level composite specimens with and without embedded FOSs assesses the dual sinusoidal placement in terms of its mechanical influence on host materials and monitoring advantages across various loading scenarios. Results highlight the strain measurement advantages of the dual sinusoidal placement compared to linear and single sinusoidal patterns. This research benefits future applications in large-scale smart composite structures by discussing the balance between mechanical effects, sensing functions, and monitoring coverage