Abstract
This paper is concerned with the prediction of transverse Poisson's ratio for softwoods on the basis of their laminated porous structures. The arrangement of cell cavities which appear in the cross section of wood was simplified by two kinds of porous models with regularly arranged circular holes, corresponding to the early-and latewood portions, respectively.
Effective Young's moduli, E*, and Poisson's ratios ν*, of these models made of an isotropic material, for which Young's modulus is E0 and Poisson's ratio, ν0, were calculated by using the finite element analysis. The results are expressed in the following equations.
E*=aE0
ν*=b+aν0
where a is the normalized Young's modulus specified by volume fraction of pores and arrangements, and b represents a part of Poisson's ratio depending only on porous structures.
For the purpose of estimating Poisson's ratio of woods, equations were derived from these simplified models. The results were compared with the experimental one reported in literature. They agreed each other qualitatively well.
