Simulation of the long-term hydrostatic tests on Glass Fiber Reinforced Plastic pipes

The main objective of this paper is to simulate long-term hydrostatic tests on Glass Fiber Reinforced Plastic (GFRP) pipes. An experimental procedure for obtaining pressure class of GFRP pipes on the basis of long-term behavior is very time consuming and costly that sometimes take about 2 years for collecting required data. Then, obtained results are extrapolated to 50 years. In this work, a theoretical modeling procedure is developed to obtain residual strength of pipes after 50 years taking into account creep phenomenon. Developed progressive modeling consists of creep modeling, stress analysis and failure evaluation. An integrated modeling procedure is developed reporting time-to-failure at any desired internal pressure. As a case study and also validation purpose, the developed modeling procedure is conducted for predicting long-term behavior of a specific GFRP pipe subjected to internal pressure. A comparison between real experimental data and theoretical modeling is presented. A very good agreement between predicted 50-year hydrostatic pressure and experimental data implies on the proficiency of the developed modeling. Since the developed modeling is just in need of short-term experimental data on pure resin, it could be used as an appropriate engineering tool for industrial centers.