Poissons Ratio Laminated Bamboo Lumber

The ratio of the transverse to axial strain is called poisson s ratio.

Poissons ratio laminated bamboo lumber. The poisson s ratio of laminated bamboo in off axis plane increased first and then decreased with the change of the off axis angle and reached the maximum when the off axis angle is 30. Poisson s ratio is a measure of the poisson effect that describes the expansion or contraction of a material in directions perpendicular to the direction of loading the value of poisson s ratio is the negative of the ratio of transverse strain to axial strain for small values of these changes is the amount of transversal expansion divided by the amount of axial compression. Wood is generally considered to be an anisotropic material. The mechanical characterization of this material includes not only the determination of its strength but also of its elastic constants.

The average poisson s ratio parallel to grain 0 and perpendicular to grain 90 are 0 31 and 0 06 respectively. Mechanical properties of wood david w. For example μlr is the poisson s ratio for. The elasticity modulus and poisson ratio of laminated bamboo.

Typical poisson s ratios for some common materials are indicated below. Poisson s ratios for common materials. Laminated bamboo is a natural composite material with cellulose fibers parenchyma cells and vascular bundles. Dr 0 334 100 10 3 m 5 10 3 m 10 m 1 7 10 5 m 0 017 mm.

By studying the elastic modulus and poisson s ratio of laminated bamboo under different loading directions takeuchi et al. To solve these problems modern industrial bamboo materials appeared in different forms such as glubam 1 2 parallel bamboo strand lumber pbsl 3 4 laminated bamboo lumber lbl 5 10 and so on. Kretschmann contents orthotropic nature of wood 4 1 elastic properties 4 2 modulus of elasticity 4 2 poisson s ratio 4 2 modulus of rigidity 4 3 strength properties 4 3 common properties 4 3 less common properties 4 24 vibration properties 4 25. The poisson s ratios are denoted by μlr μrl μlt μtl μrt and μtr.

In the engineering of elastic models wood is treated. With poisson s ratio for aluminum 0 334 the contraction can be calculated as. Bamboo tubes can be disassembled into bamboo filament bundles by passing. The bamboo culm and the low rigidity of the bamboo.

The elasticity modulus and poisson ratio of laminated bamboo. Winandy and david e. For most common materials the poisson s ratio is in the range 0 0 5.