ULTRASONIC-SCANNING AND ACOUSTIC-EMISSION OF COMPOSITE TUBES SUBJECTED TO MULTIAXIAL LOADING

Multiaxial constant loading rate tests of wound GFRP composite tubes h ave been performed, with various axial/hoop stress ratio, combining in ternal pressure and tension. Ultrasonic C-scans were recorded before a nd after loading to compare damage levels determined by mechanical (de cay of elastic moduli), ultrasonic and optical methods. During the tes ts; the acoustic emission signals from six AE transducers were analyze d. AE sources were localized by an artificial neural network aimed at the data obtained from directional wave velocity diagrams of an anisot ropic tube. The planar distributions of AE sources are related to the ultrasonic map changes. (C) 1998 Elsevier Science B.V.