Influence of Pressure and Thermal Parameters on Stresses Analysis of Pressurized and Cracked Pipes

Abstract

Due to the dangerous alarm for many engineering applications such as energy generating systems and pipelines transporting oil, gas and its derivatives under high-pressure, a study of the effect of thermal and mechanical loading on the cracked materials and pipes at high-temperature environments is required. In this work, the influence of the thermal loadings on stresses analysis of pressurized and cracked pressurized pipes has been solved numerically where the mode I crack's type has been considered. The modeling process mainly aims to find the stress intensity factor, J-integral calculations and the stress distributions. The accuracy of the results has been compared with analytical solutions of a pressurized cylinder. The mesh around the crack have been modeled in a careful way to obtain accurate stress distributions. It was found that the surface’s temperature has a significant effect on stress distributions, for example, the stresses increased by 50% with increasing the temperature differences between the inner and outer pipe’s diameter. Additionally, the stress intensity factor and the J-integrals values were calculated for different crack length ratios and temperature differences. It is found at the crack length ratio of 0.6 the stress intensity factors increased up to 50% from 45 to 76 and J-integral increased by 77% from 250 kN/m to 430 kN/m. Also, the influence of fluid’s temperature investigated, and the result showed that by increasing the fluid’s temperature without cracks, the stresses decreased by 33%. Also, it was found that for different crack length ratios the J-integral and stress intensity reduces when the fluid’s temperature increases.