ORTHOTROPIC ELASTIC-CONSTANTS FOR EASTERN HARDWOOD SPECIES

Matched samples of wood from 18 eastern hardwood trees representing IO species were loaded in compression in the longitudinal (L), radial (R ), and tangential (T) directions at approximately 12% moisture content . Strains were measured in the L, R, and T directions for each type of specimen for the calculation of non-shear elastic constants. Linear r elationships involving all the test species were investigated between pairs of engineering elastic constants, between pairs of compliance el astic constants, and between elastic constants and density. The recipr ocal compliance condition for orthotropicity was satisfied only in the RT plane. Time factors involved with loading methods and differences in time dependency with direction of loading were thought to have affe cted the reciprocal relationships in the LR and LT planes.