Influence of Elevated Temperature on the Acoustic Emission Evaluation of FRP Vessels Through Internal Fluid Pressure Tests

A research program evaluating the effect of elevated temperature in the acoustic emission testing of fiberglass vessels was completed recently. The program aimed at evaluating the current ASME provisions that require acoustic emission testing for Class II vessels be carried out at operating temperature in the event that the operating temperature exceeds 49°C (120°F). Lack of data from fiber reinforced polymer vessels and/or components that have been subjected to acoustic emission evaluation at elevated temperature has resulted in speculation regarding the appropriateness of conducting the acoustic emission evaluation at elevated temperature. To address these issues, an experimental investigation was conducted on representative coupon specimens and pressurized cylindrical specimens at differing temperatures. The results from the coupon tests were presented in a previous publication. This paper will present the results of the cylindrical specimens and compare them to the coupon specimens drawing the final conclusions from the overall results of the program. The results from this study resulted in changes in the body of the ASME code for testing pressure vessels with acoustic emission at temperature.