PACS Reference: 43.35.Cg, 43.35.Mr, 43.35.Yb, 43.20.Ks
In this work, the possibility to use a technique based on the analysis of thickness
resonances of air-surrounded aerogel plates at ultrasonic frequencies to obtain its viscoelastic properties is investigated. These resonances were excited and sensed by airborne ultrasonic waves. To this purpose, specially designed air-coupled, high-sensitivity and broad-band piezoelectric transducers were used. Precise and simultaneous measurements of velocity and
attenuation of longitudinal and shear waves at different frequencies as well as aerogel density were obtained. It allowed to afford for the first time, a full characterisation of the viscoeleastic properties of these materials at ultrasonic frequencies.
Peer reviewed