BROAD-BAND LAMB WAVE MEASUREMENTS IN ALUMINUM AND CARBON GLASS FIBER-REINFORCED COMPOSITE-MATERIALS USING NONCONTACTING LASER GENERATION AND DETECTION/

Broadband measurements of Lamb wave dispersion characteristics have be en performed in aluminium, carbon and carbon/glass fibre hybrid compos ite materials using a non-contacting optical technique. A high powered Q-switched Nd:YAG laser was used to initiate the Lamb wave spectrum i n the materials: and an optical fibre Michelson interferometer was use d to monitor the out-of-plane displacements associated with the propag ating modes. Comparison of experimental results with theoretical model ling in both the aluminium and composite samples indicated good agreem ent for the excited modes. The application of this technique to the no n-destructive testing and elastic property measurement of composite ma terials is discussed. (C) 1997 Elsevier Science B.V.