Studying the Effect of Water Hammer Shock Wave on Composite Repaired Patches Based on ASME PCC-2

Abstract

Pipelines are identified as one of the most important elements in the transmission of energy worldwide, and hence, their maintenance is of great importance. Accordingly, many standards have been developed to maintain these pipelines in services, such as ASME B31G and ASME PCC2. In recent years, composite patches are increasingly utilized to repair damaged areas Therefore, there are many studies carried out on this repair system. However, the behavior of the patches and repaired pipes has rarely been studied under dynamic pressures and water hammer phenomenon conditions. The main objective of this paper is to study the effect of the water hammer phenomenon on the damaged area of the steel pipe. Moreover, the behavior of the composite patch, which was used for repairing, after the passage of the pressure wave is studied. Furthermore, the effect of strain rates on composite patch damage is investigated by a specific VUMAT subroutine in the numerical model. It was found that despite the good resistance of the steel pipe in the damaged area, the composite patch is very vulnerable and fails after the water hammer shock wave. Therefore, it is recommended that for all pipelines where there is a risk of water hammer impact, repaired patches, based on ASME PCC2, should be re-examined and restored. © 2021, ASM International.