Abstract:

The elasticity and elastoplasticity variation laws of longitudinal compressing elm wood study could enhance wood one-way bending performance in order to achieve wood multi-dimensional bending. Juvenile and mature elm wood was longitudinal compressed after compound alkali liquor processing, then stress-strain constitutive relations were established. The results showed that at the beginning of compressing, the curves of stress and strain accorded with linear Hooke’s Law, similarly, they satisfied a linear mechanic relationship in the elastoplasticity region. During longitudinal compressing, why juvenile elm wood has high variability, longitudinal compressive modulus of elasticity, stress and strain, which attribute to the degradation and extractive of elm wood chemical component after compound alkali liquor processing, were analyzed. Then basic variation laws of elasticity and elastoplasticity were found. In the elastic-plastic region, stress-strain curves displayed smoothly, in which folds were formed on wood cell walls.

Key words: elm, longitudinal compressing, juvenile wood, mature wood, variation laws of stress and strain