Numerical Analysis of Crack Failure of Reinforced Thermoplastic Pipe (RTP)

Abstract

Composite pipeline can drastically reduce losses caused by corrosion that occurs in carbon steel pipes in the industry. Multiple numerical testing has been conducted to determine maximum stress and strain a Reinforced Thermoplastic Pipe (RTP) can withstand before hitting failure. Not many studies were done to find the maximum stress intensity a defected RTP can resist before failing. Objectives are to validate the numerical model for Reinforced Thermoplastic Pipeline (RTP) to industry standard and to analyze the maximum stress intensity of Reinforced Thermoplastic Pipes (RTP) can withstand with various size of defects under constant pressure and incremental internal pressure with constant crack defect. Results were, under constant internal pressure of 6 MPa, the pipe will fail with a defect length of 2.05mm and at constant design pressure of 10 MPa, the pipe will fail with a defect length of 0.3mm. At constant crack depth and width, crack tip propagation (failure) is more dependent on internal pressure rather than crack length. However, when comparing the severity of crack depth to internal pressure, crack depth is the major cause of failure.

Finite Element Modeling of the Thermomechanical Behavior of Polyethylene

“…Our study is based on a real problem, the case of the injection blow molding process essentially dedicated to the manufacture of the bottles for the packaging of food products (milk), the experimental data taken will be used later in numerical resolution. The boundary conditions and the thermal and mechanical characteristics of the high-density polyethylene part are as follows (Table 1) [21,22] and the mechanical and thermal characteristics of the Duralumin mold are shown in (Table 2) [23][24][25]. Knowing the shape of the molded part, the thermal properties of the plastics, and the manufacturing conditions, it is possible to make a good approximation of the cooling time for several years, the following equation for the calculation of tc (equation 14) [26,27].…”