Comparison Between Ultrasonic and Mechanical Young’s Modulus of a Bio-composite Reinforced with Olive Wood Floor

Ultrasonic testing is a technique frequently used in the field of nondestructive evaluation given the fact that ultrasonic waves are directly related to the mechanical behavior of materials. It is for this reason that mechanical waves are often involved in solid material testing and the evaluation of their mechanical properties. As such, ultrasonic velocity is often used to identify so-called healthy concrete in comparison to deteriorated concrete. The objective of the present study is to determine Young’s modulus of a bio composite using two methods: ultrasonic and mechanical methods. For this, a bio-composite based on polypropylene (PP) as a matrix and the olive wood flour (OWF) as a reinforcement was elaborated with extrusion using a twin extruder following by the injection in the form of 4 mm thick plate for ultrasonic control and standardized specimens for tensile testing. The longitudinal and transversal velocity of propagation of the wave in the plates is measured with the technique of immersion in water using transducer at 5 MHz center frequency in order to determinate the ultrasonic Young’s modulus. Results show that the ultrasonic Young’s modulus of the studied bio-composite is different than that mechanical Young’s modulus. The causes of this difference will be studied.