Abstract
The mechanical strengths of wood are calculated, for safety reasons, based on their characteristic value. The Brazilian standard for timber structures establishes relationships to estimative the characteristic strength together with three forms of wood characterisation, with emphasis on the simplified procedure that allows, for usual species, obtaining the characteristic values through equations that correlate different mechanical properties. Considering the results of strengths (c0; t0) and of the modulus of elasticity (Ec0; Et0) on the compressive and tensile parallel to the grains of 40 hardwood species (960 experimental determinations with ≈ 12% moisture content), the precision of the relations c0,k = 0,77 ∙ t0,k and Ec0 = Et0 proposed by the standard were evaluated based on the analysis of variance (ANOVA). Besides the objective of evaluating such equations, linear, exponential, logarithmic and geometric regression models were adopted as an alternative proposal in the estimation of such properties. The statistical analyzes validated the equations proposed by the Brazilian standard, and the geometric equation, proposed in this work, proved to be the best fit model.
Keywords:
Hardwoods; Regression models; Characteristic values
