A novel device for measuring the ultrasonic wave velocity and the thickness of hyperelastic materials under quasi-static deformations

An innovative low-cost testing machine for measuring simultaneously the ultrasonic longitudinal wave velocity and the thickness of hyperelastic material specimens, while applying a quasi-static deformation, is described. In a pulse-echo ultrasonic immersion test, both of these parameters can be obtained by measuring several times of flight, once the speed of sound in the coupling fluid at the testing temperature is known. The variation in ultrasonic longitudinal wave velocity through the sample when the deformation changes is called the acoustoelastic effect. Knowledge of this effect allows the material characterization. The results obtained on SBR-1502 reinforced with carbon black (20%) are in accordance to the values presented in literature and thus confirm the validity of the proposed experimental device.