Stress analysis in the buried polyethylene pipes with viscoelastic behavior: a finite element study

Abstract

Abstract In the current study, the stress distribution in the pipe with viscoelastic behavior in presence of different loading conditions has been investigated. In order to connect the polyethylene (PE) gas pipes, the electrofusion sockets are used. Since joints are one of the most sensitive regions of a structure, it is very important to investigate the local stresses created at the joints of PE pipes. To study the stress changes in the buried pipelines and sockets, the numerical simulation of the problem has been carried out in ANSYS software. To validate the obtained numerical findings, the maximum values of the axial and von Mises stresses in the pipe and socket were compared with the values obtained from previous research, and an acceptable overlap was achieved. In this research, the stress distribution in the PE pipes buried in the soil with and without sockets in presence of thermo-mechanical load has been studied, comprehensively. In the finite element modelling, the pipe and socket are made of PE80 and PE100 materials, respectively. The research results showed that the electrofusion sockets are able to be employed to connect PE gas pipes in hot climate regions. Additionally, the outcomes obtained from viscoelastic socket and pipes compared with the isotropic pipe. The findings demonstrated that the maximum von Misses stress in viscoelastic pipe and socket reduces 21% in comparison with linear elastic state.

Keywords

• Buried gas pipes
• Electrofusion socket joints
• Axial stress
• Von Mises stress
• Finite element method