Longitudinal modulus of elasticity of Chinese fir tracheids

This paper calculates the longitudinal modulus of elasticity of Chinese fir tracheids (Ecell) by measuring the wood specimen’s airdried density and tensile modulus of elasticity parallel to wood grain. The variation of Ecell within a tree and the relationship between Ecell and microfibril angle (MFA) were investigated. Results indicated that Ecell exhibited a larger variation in the radial direction than in the longitudinal direction (tree height direction). The average Ecell of all tested samples was 44.06 GPa. The tracheids close to the pith had relatively lower Ecell valued at 16.36 GPa. With increasing MFA, Ecell dccreased significantly. When MFA was higher than 24°, the decreasing range of Ecell became more gradually.