Shear and longitudinal modulus of elasticity in structural profiled round timber beams

Abstract

This research aimed to present, with the aid of the three-points static bending, conducted nondestructively, analytical methodology to determine the longitudinal (E) and the shear modulus (G) of elasticity in round timber beams. The wood used was Eucalyptus clones. Were used three different values to the form factor coefficient of the circular cross section, allowing evaluating the differences between the shear stiffness values obtained. The results of the analysis of variance indicated no statistical equivalence between the shear modulus of elasticity, revealing be significant the influence of the form factors used to determine the shear modulus of elasticity. The coefficient (λ) of the relationship between the modulus of elasticity (E=λ·G) obtained from the least squares method were equal to 118, revealing 5.9 higher than the relationship (E=20·G) presented in the Brazilian standard ABNT NBR 7190:1997. It is emphasized that these results may be different for the same or different wood species, justifying the use of this methodology in each research developed.