Calculation of the stress-strain state of the "pipe-composite wrap" system

Abstract

This study focuses on the application of composite materials for strengthening and repairing worn pipelines. The influence of various structural and operational factors on the stress state of a pipe reinforced with a composite wrap was investigated. A comparative analysis was conducted between the calculations of a steel pipe reinforced with a composite using the finite element method and several analytical methods, including those specified in DSTU ISO 24817:2019. Numerical and analytical calculations were carried out according to a full factorial experiment plan (three factors at three levels, twenty-seven experiments in total), with the variable factors being the wrap thickness, pipe thickness, and the ratio of residual thickness to pipe thickness. The calculations involved two system variants: "undamaged pipe" and "damaged pipe." A new analytical approach was proposed to determine the stress-strain state of the "pipe-composite wrap" system, which provides higher accuracy compared to DSTU ISO 24817:2019.