Collapse of RTP (Reinforced Thermoplastic Pipe) Subjected to External Pressure

Abstract

The collapse of reinforced thermoplastic pipe (RTP) under uniform external hydrostatic pressure is investigated in this paper. Extended from the model initially proposed by Kyriakides and his co-workers, a 2D theoretical model which takes into account the mean radius change, the wall thickness change, transverse shear deformation, and pre-buckling deformation is further developed. The reinforced layers, consisting of PE and aramid strands, are taken as homogeneous layers and equivalent stiffness method is used to get their mechanical parameters. J2 flow theory with isotropic hardening is adopted to model the plastic property of the material. By means of numerical calculation, the ovalization-pressure curve and ovalization-strain curve of RTP are presented. To confirm the accuracy of the theoretical model, numerical simulation is conducted using a 2D finite element model within the framework of ABAQUS. It is found that the results obtained by theoretical method and finite element method show good agreement. Finally, the effects of several parameters are studied by use of the theoretical model and useful conclusions are drawn.