Ultrasonic properties of fly ash/polyurea composites

An experimental study has been conducted to determine the mechanical properties of fly-ash/polyurea composites by measuring their longitudinal and shear wave velocities, and attenuations at various fly ash volume fractions, using ultrasonic. The complex-valued longitudinal and shear moduli were computed from these measurements at various temperatures. It was observed that a 30% volume fraction addition of fly ash has increased the longitudinal storage and loss moduli and shear storage and loss moduli by up to 22%, 141%, 298% and 125%, respectively. The complex bulk modulus and Poisson's ratio of the composites at 1 MHz were also estimated. Additionally, a computational model based on the method of dilute-randomly-distributed inclusions was created to estimate the dynamic mechanical properties of the composites. The experimental and computational results were compared and showed good agreement. (C) 2015 Elsevier Ltd. All rights reserved.