Empirical formula of buckle propagation pressure for sandwich pipes with polymer core material

The sandwich pipe, with its high hydraulic pressure resistance and thermal insulation properties, presents itself as a potential choice for deepwater oil and gas exploration. This study developed a 3D finite element numerical model using ABAQUS software to simulate the collapse propagation of sandwich pipes under the high external hydraulic pressure. A parametric analysis was undertaken using a numerical model, which had been calibrated by experimental tests. The study aimed to assess the contributions of material properties, such as yield strength and Young's modulus, as well as geometric dimension, to the collapse propagation behavior of the sandwich pipe. Moreover, a simplified empirical formula was formulated to research the propagation pressure of polymer sandwich pipes. The research also investigated the contribution of the interaction property between the core layer and inner/outer steel layer on the propagation pressure. An interfacial factor was incorporated into the present simplified empirical formula. The empirical formula was validated using experimental results and data from various sources, including real interlayer interactions observed during tests. The results indicate that this formula offers an accurate prediction of the propagation pressure for polymer sandwich pipes.