Acoustic emission performance of fiber reinforced plastic pressure vessels at high temperatures

This study involved the evaluation of Acoustic Emission (AE) parameters at high temperatures and examines the validity and applicability of the current AE acceptance criteria for inspecting pressure vessels at these temperatures. The study consisted of internal pressure tests under static loads on filament wound Fiber Reinforced Plastic (FRP) pipe specimens. These specimens were manufactured using four different resins having different extensions to failure. Two test temperatures, 140°F and 190°F were selected for testing. Results indicated AE may be used as an effective tool for testing FRP pressure vessels at high temperature under internal pressure loading. The results also indicated that the current AE acceptance criteria was effective in inspecting these specimens at high temperatures. AE monitoring was also effective in indicating creep at these temperatures. The Large amplitude hits criterion was ineffective in indicating damage at high temperatures as shown by the relative absence of these events at high temperatures as compared to ambient. Results also indicated that as the temperature increases the load at the onset of significant emission decreases. AE was also effective in predicting damage as was seen from the low values of Felicity Ratio calculated.