Efficiency of Carbon Fibre Buckle Arrestors for Subsea Pipelines

Abstract This paper experimentally investigates the feasibility and efficiency of using Carbon Fiber Reinforced Polymer (CFRP) buckle arrestors in controlling the buckle propagation failure of subsea pipelines. Hyperbaric chamber tests are conducted on 1.6m Steel pipe with D/t = 28 and using CFRP buckle arrestors with different thickness, fiber orientation and spacing. Using an external pressure gauge and a high-pressure camera inserted inside the hyperbaric chamber, the pressure magnitude, rate and shape of collapse and its propagation in the vicinity of the arrestors are measured. The dynamics of buckle propagation and efficiency of different arrestor configurations are reported. It is observed that in the vicinity of the CFRP arrestors wrapped in the hoop direction, the well-known dog-bone buckle shape changes into a U-shape and the pressure level upsurges significantly. The optimum results were obtained with CFRP as thick as the pipeline wall-thickness and wrapped in the hoop direction of the pipeline. The results show that at similar arrestor efficiency, the CFRP arrestors can be much thinner than the existing steel slip-on arrestors. Also, the spacing between the CFRP arrestor can be larger than that of the steel slip-on arrestor.