Comparison of Two Methods to Determine the Bending Modulus of Elasticity of Wood

Abstract

The modulus of elasticity is among the main properties required for the dimensioning of a wood structure. It can be calculated using different test methods, the most commonly used are the 3 and 4 points bending tests. The Brazilian standard, ABNT NBR 7190: 1997, recommends the 3-point static bending test. Studies about the influence of testing methods to determine the bending modulus of elasticity are always relevant, since can improve its reliability. Thus, the aim of this study is to examine the bending modulus of elasticity of samples of nine Brazilian wood species: Cambará Rosa (Erisma uncinatum Warm), Caxeta (Tabebuia cassinoides), Tatajuba (Bagassa guianensis), Itaúba (Mezilaurus itauba), Branquilho (Termilalia spp), Cedro Amazonense (Cedrelinga catenaeformis Ducke), Roxinho (Peltogyne spp.), Cumaru (Dipteryx odorata) and Cambará (Gochnatia polymorpha). The results of the confidence intervals have showed that the moduli of elasticity for both test methods were equivalent at 5% significance level.