Equivalent Calculation of Critical Collapse Pressure of Flexible Pipes and Parametric Analysis of Collapse Influence Factors

Abstract

Collapse bucking is a typical failure mode of flexible pipes during deepwater service. It is essential to investigate the failure characteristics and obtain the accurate critical collapse pressure to improve the design of flexible pipes and make them more durable in a deepwater environment. Firstly, an equivalent layer method based equivalent hoop stiffness is presented in the paper. Then, the proposed method is verified by corresponding comparative analysis. Next, two-dimensional (2D) collapse numerical models are created based on the verified method. Finally, the parametric analysis of collapse influence factors is carried out by the arc-length method. The results show that the equivalent method is valid and convenient for obtaining the equivalent thickness of the carcass layer. The parametric analysis results under different collapse influence factors can provide some useful advice for collapse-resistant design of flexible pipes.