We determined the individual laminae elastic constants in multilayer laminates composed of dissimilar isotropic layers using acoustic resonance spectroscopy and the linear theory of elasticity. Resonant ultrasound allows one to measure the free-vibration response spectrum of a traction-free solid under periodic vibration. These frequencies depend on pointwise density, laminate dimensions, layer thickness, and layer elastic constants. Given a material with known mass but unknown constituation, this method allows one to extract the elastic constants and density of the constitutent layers. This is accomplished by measuring the frequencies and then minimizing the differences between these and those calculated using the theory of elasticity for layered media to select the constants that beat replicate the frequency response spectrum. We apply our approach to a three-layer, unsymmetric laminate of WpCu and find very good agreement with the elastic constants of the two constituent materials.
Citation: Journal of the Acoustical Society of America
Issue: No. 5
Pub Type: Journals
composite, cooper, elastic constants, graded material, laminate, tungsten, ultrasonics