Find in Library

In this investigation, the potential of flexural vibration method as nondestructive tool was studied in order to evaluate the acoustical and the mechanical properties of bagasse composites. For this purpose, more than 40 cubic samples (36×4×1.6 cm3) were taken from the given materials. The results showed that the acoustical behavior of particle board were better than that measured for medium density fiber board. In MDF samples, the resonance frequency, the sound velocity, the quality factor as well as the acoustic coefficients were significantly lower than those measured in PB samples. In contrast, the internal friction measured in MDF was greater than values of PB. But no significant difference was observed of ACE in both MDF and PB samples. The young's modulus of MDF and PB were obtained by conducting a flexural vibration method under the free- free condition based on Timoshenko's vibration theory. The results were also compared with the modulus of elasticity and rupture calculated by 3 point bending test. The modulus of elasticity values, measured by dynamic method were 15% and 6% higher than those achieved by static bending method for MDF and PB respectively. It was also illustrated that the modulus of elasticity and the sound velocity were significantly positively related to the density of MDF and PB while the other acoustical properties had negative relations with density. As good correlations were found between dynamic and static modulus of elasticity (0.71) and also static modulus of rupture and dynamic modulus of elasticity (0.44), it can be drawn that the flexural vibration is valuable tool in order to evaluate mechanical properties of MDF made by bagasse while the same results were not observed in PB composites.