ACOUSTIC SURFACE WAVE-GUIDES FOR ACOUSTIC-EMISSION MONITORING OF FIBER-REINFORCED PLASTIC STRUCTURES

Acoustic surface waveguides are developed to enhance the transmission of acoustic emission (AE) signals in high attenuating fiber-reinforced plastic (FRP) structures. In this paper, the design of the surface wa veguide system and the source location technique are described. Experi mental results of using a surface waveguide for AE monitoring of a FRP composite pressure pipe are presented to demonstrate the effectivenes s of the proposed waveguide system. A metal wire was selected as a wav eguide, and pencil breaks and electronic pulses were used as artificia l AE signals. The results indicate that the use of the surface wavegui de can significantly increase the AE monitoring range. Also, a high tr ansmission efficiency was experimentally determined for the epoxy join ts developed to attach the surface waveguide to the FRP pipe. The prop osed surface waveguide appears to be a promising technique for AE moni toring on existing FRP pressure vessels and storage tanks.