Experimental procedure and results for the identification of elastic constants of thick orthotropic plates

摘要

Elastic constants of thick orthotropic plates are determined by a numerical/experimental method. Four in-plane elastic constants and two transverse shear moduli are deduced from typically 10 to 15 natural frequencies of the completely free plate. Focus is here on the experimental technique and the application of the method in real test. High quality frequency measurements are performed by the impulse technique combined with advanced curve fitting of the frequency response function. The different sources of modelling and experimental errors associated with the method are discussed. The practical performance of the method is illustrated by results for an aluminium plate and for two different unidirectional composite plates. For the composites, close agreement is found between in-plane and out-of plane shear moduli in the planes parallel to the fibres, confirming transverse isotropy. Comparisons with conventional tensile tests for the in-plane properties show good agreement. (au) 22 refs.