Estudo de propriedades mecânicas de dicotiledôneas por meio de ensaio não- -destrutivo utilizando equipamento de ultra-som

This work presents a study of an application of ultrasonic techniques in order to characterize physical and mechanical properties of wood. The ultrasonic wave application is based on the relationship between the speed of the sound, the modulus of elasticity and the density. The species of wood used were: eucalipto grandis, eucalipto citriodora, cupiuba and jatoba. The experimental program was divided in two steps: the first related to small samples, and the second one related to samples with structural dimensions. Rehearsals were accomplish for the determination of the following physical and mechanical properties: apparent density at 12% (ρap,12%), strength and modulus of elasticity in compression parallel to the grain (fc0 and Ec0), modulus of elasticity (MOE) and modulus of rupture (MOR). They were also made ultrasonic measurements for obtaining the dynamic modulus of elasticity (Ed), in order to comparison with the static results. The experimental results show that it is possible to use the ultrasonic technique satisfactorily to characterize wood mechanically, obtaining reliable relationships.