Behavior of Reinforced Thermoplastic Pipe (RTP) under Tension

摘要

Recently, Reinforced Thermoplastic Pipe (RTP) is increasingly applied in the oil and gas industry. Since tensile behavior is a fundamental property of RTP, both theoretical method and numerical simulation are used within this paper to study the behavior of RTP under tension. In theoretical method, the model proposed by Knapp is modified and further applied to RTP, considering the interaction between pipe and wires as well as material nonlinearity. Equilibrium equations are derived based on the principle of stationary potential energy. Using Newton-Raphson method, the problem is solved by an iterative procedure. As for the finite element model, solid and truss elements are used to simulate the HDPE layer and wire respectively. Results from both methods are compared and an agreement between the theoretical method and numerical simulation is obtained. Both methods can offer valuable advice for RTP design and application.