Development of fibre optic ingress/egress methods for smart composite structures

The fibre optic ingress/egress is one of the important issues for the application of fibre optic sensors to real structures because the optical fibre is so fragile at the ingress/egress point. Little attention has been paid to methods of practically accessing embedded optical fibres in the literature of sensor activities. In this paper, we propose the novel out-of-plane ingress/egress method to improve the limit of the existing in-plane ingress/egress method. For the safety of the embedded optical fibre, we developed a component to protect the optical fibre at the ingress/egress point and a preservation method for an optical fibre against the composite curing environment of high temperature and pressure. We also developed an optical connection fixture to integrate the connection part and a composite structure. Some tests were performed to confirm the safety and survivability of the embedded optical fibre using the devised ingress/egress method.