Design and Development of a Composite Tube With Embedded Distributed Fibre Optic (DFO) Sensing

Abstract The primary aim of this research is to analyze and evaluate the design of a composite tube that is structurally embedded with distributed fiber optic sensors to enable real-time monitoring in challenging subsea environments, especially associated with subsea drilling and well-completion applications. This investigation utilizes the Finite Element Analysis (FEA) based numerical simulations tool to assess the feasibility from the perspective of structural integrity and reliability. This research analyses the mechanics of polymers and reinforced resin composite materials embedded with DFO. Emphasis is given to the angle and placement of different DFO sensing methods to match the composite lay-up and design premise. Two sensor lay-up scenarios, longitudinal and helically wrapped up, are analyzed for cross-section and longitudinal span design under various loading conditions. The helical lay-up of DFO placed in a grooved slot on the outskirts of the thermoplastic inner shell demonstrates promising results in the burst, axial compression, buckling, and reeling loading cases. The stress results are presented in a ply-by-ply manner for each lay-up for composite design, together with the stress results of the thermoplastic pressure barrier layer. These results establish a sound technical basis for the proposed design scenarios.