Evaluation of Fatigue Phenomenon Effect in Polyvinyl Chloride Pipes Under Reversible Cyclic Loads

The Experimental studies show that the number of pressure cycles, cross-sectional pressure limits and average pressure applied to the PVC material in the transition phase are among the parameters that lead to fatigue in PVC pipes. Based on these studies, standards have been designed that provide the information needed to calculate the allowable number of pressure cycles on PVC pipes. The number of these allowable pressure cycles is reported to be less than the fatigue resistance limit of PVC pipes to ensure the safe use of PVC pipes. In the meantime, determining the number and range of temporary pressure cycles is a problem that should be obtained from the analysis of cross-sectional pressure results. The Institute of Plastic Pipes proposed the idea of using the PACE computer program to analyze fatigue failure in PE and PVC pipes, but the concept of transient stress intensity in the system is ignored in this program, so the results obtained in Most real systems are controversial. This research helps to improve the basic ideas of the PACE program . In order to analyze the fatigue, a hypothetical pumping system was built using the PACE program, as well as the analysis of different pump performance conditions. The results, which are somewhat predictable, show that fatigue analysis of PVC pipes is very important. Therefore, the concept intended by the PACE program is very simple. In addition, numerical results show that PVC pipes are reliable against fatigue failure in a wide operating range, and fatigue analysis of transient pressure data can also be reliable .

Keywords:

PVC Pipe , Fatigue , Cyclic Load , Functional