UC San Diego

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.