Porous Structure of Wood and its Relaxation Modulus, II

Abstract

The effects of the environmental condition on the relaxation modulus of wood as a porous anisotropic material was discussed with the help of the numerical value of n, which is an index of anisotropy decided by both the geometrical feature of the deformable unit of wood at macroscopic level and its volume fraction. It was found that the numerical value of n was independent on time, temperature and moisture. Therefore, it may be considered that the relaxation process of wood is due to that of wood substance. Furthermore, strain dependence of n is descussed. It was found that n is almost independent on the strain in the tangential direction.