Poissons Ratio Laminated Bamboo Lumber

Typical poisson s ratios for some common materials are indicated below.

Poissons ratio laminated bamboo lumber.

Wood is generally considered to be an anisotropic material. 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. The bamboo culm and the low rigidity of the bamboo. Mechanical properties of wood david w.

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. Bamboo tubes can be disassembled into bamboo filament bundles by passing. Winandy and david e. In the engineering of elastic models wood is treated.

The average poisson s ratio parallel to grain 0 and perpendicular to grain 90 are 0 31 and 0 06 respectively. With poisson s ratio for aluminum 0 334 the contraction can be calculated as. Poisson s ratios for common materials. The elasticity modulus and poisson ratio of laminated bamboo.

By studying the elastic modulus and poisson s ratio of laminated bamboo under different loading directions takeuchi et al. The ratio of the transverse to axial strain is called poisson s ratio. The elasticity modulus and poisson ratio of laminated bamboo. 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.

Given the anisotropic nature of the laminated material compression tests were performed on three groups of specimens. The poisson s ratios are denoted by μlr μrl μlt μtl μrt and μtr. 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 first letter of the subscript refers to direction of applied stress and the second letter to direction of lateral deformation.

Laminated bamboo is a natural composite material with cellulose fibers parenchyma cells and vascular bundles. 19 proved laminated bamboo could be treated as orthotropic material. For most common materials the poisson s ratio is in the range 0 0 5.