Elastic properties of composites: periodical homogenisation technique and experimental comparison using acoustic microscopy and resonant ultrasonic spectroscopy.

The macroscopic elastic properties of two composites (Duralumin/air and Duralumin/tungsten carbide (WC)) have been calculated using periodical homogenisation methods and the elastic properties of each phase (measured by high frequency acoustic microscopy). In order to check the validity of such an approach, acoustical resonant spectroscopy has also been applied. Thanks to the comparison between the resonant frequencies predicted and measured, two major conclusions have been obtained: the homogenisation method is very accurate for the composite Duralumin/air, but not for the Duralumin/WC sample: the experimental results are not in very good agreement with the simulation. This result can be then explained by the major role of interfacial state between Duralumin and tungsten carbide.