Acoustic Vibrational Properties Of Bamboo, Bamboo Floor And Wood-based Panels

This paper focuses on acoustic vibrational properties of Moso bamboo, bamboo floor, plywood, particleboard and fiberboard, and analyses a relationship between physical properties and acoustic properties. The aim is to find the factors that influence the acoustic vibrational properties of these materials, make comparison between different testing methods, and further use acoustic properties to predict physical properties of materials.Firstly acoustic vibrational properties of Moso bamboo were measured by resonance method. The results showed that the regression of dynamic Young's modulus of bamboo chip to its density was significant. Longitudinal sound velocities of each layer's bamboo, including outer, core, and inner plies at radial direction, were calculated. And after heat treatment with temperature of 150℃in 2 hours, the vibration efficiency of bamboo was improved and a better ability to transmit vibration energy to air was attained.Secondly acoustic vibrational properties of different kinds of bamboo floor were measured by a resonance method and a tapping test based on Lab VIEW. The results showed that the regression of acoustic vibrational properties of bamboo floor to its density was significant. The slide-pressed and carbonized bamboo floor had better acoustic vibrational properties. These two methods can both measure dynamic Young's modulus of bamboo floor well. E/G, which indicates musical quality, was discussed briefly.Thirdly the same methods were used to measure acoustic vibrational properties of wood-based panels, including plywood, particleboard and fiberboard. Different factors for each kind of board that influence acoustic properties were found. The results showed that longitudinal test piece of plywood, high density and thin particleboard and fiberboard would have better acoustic vibrational properties.Finally the relationship between acoustic vibrational properties and physical properties of these materials were studied. The results showed that the trends of static physical properties and dynamic Young's modulus were almost the same, and value of dynamic Young's modulus was a bit higher than that of static physical properties. Dynamic Young's modulus measured by resonance method was more close to physical properties. The specific dynamic Young's modulus and acoustic impedance of wood-based panels had linear regression to MOR/MOE. So these two parameters could be used to predict physical properties of board, which could make up for the deficiency of the relationship between dynamic Young's modulus and physical properties.