Functional relationships among physical and mechanical properties of Brazilian tropical woods

Abstract

This study was done with the objective of evaluating the functional relationships among the physical and mechanical properties of 163 species of Brazilian tropical woods, and also to offer mathematical tools that allow the estimation of them. Evaluations of correlations and of regression analysis were done, and the data of the samples were obtained according to the COPANT standards. The properties used were: basic density (ρ_bas), tangential (ε_r,3) and radial (ε_r,2) shrinkages, Janka hardness parallel (f_H0) and crossection (f_H90) to the grain, and those properties related to the resistance to mechanical efforts of compression (f_c0 and E_c90), static bending (f_M and E_M0), traction (f_wt90), cleavage (f_v0) and shear (f_s0). The correlations were expressed by the coefficient of linear correlation of Pearson and in the regression analysis ρ_bas was used as independent variable. Analysis of the statistical suppositions were carried out in order to do adjustments of the regression equations. The properties with the highest functional relationships were f_c0, f_H90, ρ_bas, f_M, f_H0, E_M0, f_s0 and E_c90 and the lowest were ε_r,3, ε_r,2, f_wt90 and f_v0. The regression analysis made possible the obtaition of satisfactory equations for estimates of the physical and mechanical properties of Brazilian tropical wood species with the highest functional relationships.