Comparison of damping

For PMMA, resonant peaks were sufficiently broad that higher modes in RUS began to overlap. Comparison of damping over the frequency ranges for broadband viscoelastic spectroscopy and RUS for indium tin alloy in shear modes of deformation discloses a continuation of the tan delta power-law trend for ultrasonic frequencies up to 300 kHz. RUS scans from 50 kHz to 500 kHz were conducted on cubical visco elastic foam mattresses specimens of several materials including brass, aluminum alloys and PMMA, a glassy viscoelastic polymer. This article compares resonant ultrasound spectroscopy and other resonant methods for the determination of viscoelastic properties such as damping. The specimen is contained within the brass enclosure to the left in this lab image.