Mechanical response and stress equation of pressure pipe liner passing across circular corrosion

Abstract Corrosion is one of the most common forms of damage to pressure pipes. CIPP liner can improve the mechanical properties of the pipe with corrosion. It is very important to study the mechanical response of corrosion pipes rehabilitated by CIPP liner. In this study, a three-dimensional finite element model of a pressure pipe rehabilitated with CIPP liner under the condition of circular corrosion is established, and the model is evaluated by using the experimental and analytical results. Afterward, the influence of each parameter on the stress and displacement of the liner is analyzed. Finally, the liner stress calculation equation is obtained based on 870 sets of data. The results show that the finite element results are in good agreement with the experimental and analytical results. The maximum stress of the liner first occurs at the center of the corroded circle, and as the corrosion diameter increases, the maximum stress gradually shifts to the edge. The maximum stress of the liner increases first and then tends to be stable with the increase of the corrosion diameter, and the friction coefficient has little effect on the liner stress.