Thermomechanical Modeling of a Sleeve Rehabilitation System for Pressure Pipes

Abstract

The thermomechanical modeling of a sleeve rehabilitation system for pressure pipes is studied including temperature effect on system behavior. The rehabilitation system consists of a multicylinder axisymmetric layer system, with an intermediate layer of epoxy resins and two outer steel covers that are longitudinally welded forming a sleeve. The analysis is conducted over several stages; initially, the incidence of temperature on the rigidity of three types of resins currently available on the market is experimentally evaluated. Then, nonlinear relationships between rigidity and temperature are established from the evaluation of the resins, which are typical of an inhomogeneous material. The resins exhibit a significant loss of rigidity with temperature, generating a risk of delamination that could drastically reduce the effectiveness of the rehabilitation system in the event of possible temperature rises. An analytical model was developed to calculate contact pressures between the resin layer and the external sleeve, internal pipeline displacements, stresses, and deformations. Finally, contour plots were developed for different temperature, pressure levels, and pipe thickness as a graphics tool to predict pipeline failure due to plastic deformation or rupture.