Wood / Bamboo Composite Bus Backplane Performance And The Elastic Modulus Prediction

In order to investigate the static mechanic properties of wood-bamboo composite city bus- floor, elastic modulus and strength of component materials——poplar veneer, bamboo shoot and wood-bamboo composite city bus-floor were measured by uniaxial tension, electrometry and three-point bending.For normal poplar veneer, normal press poplar veneer and adhesive-soaking poplar veneer, elastic modulus, strength and Poisson's ratio were investigated. The effects of pressure on elastic modulus and strength were analyzed. For wood-bamboo composite city bus floor, the effects of span on Modulus of elasticity(MOE) and Modulus of rupture(MOR) were investigated and analyzed. At the same time, for wood-bamboo composite city bus floor after fatigued, Modulus of elasticity(MOE) and Modulus of rupture(MOR) were investigated when different length of spans and compared with the result of wood-bamboo composite city bus floor before fatigue test. For adhesive-soaking bamboo shoot by 4MPa pressure, tension elastic modulus along the grain, Poisson's ratio, MOE and MOR were investigated. Finally, the prediction model of elastic modulus is found by using classical laminate theory.The results were summarized as follows:For normal poplar veneer, the range of elastic modulus along the grain is 4000MPa～5000MPa and the range of tension strength along the grain is 40MPa～70MPa.When poplar veneer was soaked with PF adhesive, tension properties along the grain compare favourably with tension properties along the grain of normal poplar veneer.For adhesive-soaking poplar veneer of 1.1mm, 1.4mm and 1.7mm, when pressure are 1MPa and 4MPa, Poisson's ratio are respective 0.22, 0.35, 0.40 And 0.21,0.28,0.35; Poisson's ratio of adhesive-soaking bamboo shoot by 4MPa pressure is 0.33.For adhesive-soaking poplar veneer of 1MPa and 4MPa, the range of tension elastic modulus tangential elastic module are respective 230MPa～410MPa, and 550MPa～850MPa; the range of tangential Modulus of elasticity(MOE) are respective 240MPa～385MPa and 560MPa～650MPa. As result of tension strength and tangential Modulus of rupture(MOR) are very small, it indicates that the properties of tension and bending are very bad.The relationship between elastic modulus and adhesive pressure is non-linear. With the increase of the adhesive pressure, elastic modulus reduce. It indicates that poplar veneer was squished.