Investigation on the High Strength Joints for Non-Metallic Composite Pipelines

Abstract Non-metallic composite pipelines are widely used in various fields due to their excellent flexibility and corrosion resistance. While the mechanical strength of non-metallic composite pipes has been significantly enhanced through methods such as wire and fiber reinforcement, the pipe joints have become the weak points of the pipeline system, which limits the overall performance improvement of non-metallic composite pipeline systems. In this study, a high-strength mechanically reinforced joint was specifically designed to address this issue by incorporating both axial and circumferential reinforcement to enhance the joint strength. Firstly, the bursting strength tests of the high-strength mechanical reinforced joints were conducted, the results indicate that the structural strength was significantly improved compared with the existing pipe joints, demonstrating the effectiveness of the axial and circumferential reinforcement approach. Subsequently, failure mode analysis was performed to identify the critical failure mechanisms of the high-strength mechanical reinforced joint, and the key factors influencing the structural strength of the joints were examined. Furthermore, a finite element model of the high-strength mechanical reinforced joint was constructed, and the stress distribution in the joint was analyzed. The results of this study provide valuable technical support for the design of high strength connection joints for non-metallic composite pipelines, particularly for composite pipelines in critical energy applications.