EFFECT OF THE SPECIFIC GRAVITY ON STATIC BENDING PROPERTIES IN PLYWOOD OF Pinus elliotti Engelm

Abstract

The objetive of this work was to determine the relation between the rigidity and strength properties in static bending and specifie gravity of plywood manufactured from five veneer of Pinus elliotti Engelm, plantation from a 30 year-old. Linear simples, multiple and polynomial relations involving the modulus of rupture (MOR), modulus of elasticity (MOE), strees at proportional limit (TLP) and specifie gravity (Me) of the plywood were studied. The specifie gravity did not prove to be a very exact indicator of the rigidity and strength properties of the plywood. The MOE, MOR and TLP in static bending of the plywood showed low coefficients of correlations and determination adjusted for simple linear regression, indicating a little dependence of the specific gravity. The modulus of rupture in static bending on the principal directions (x and y) had a strong dependence of the modulus of elasticity and stress at proporcional limit. The coefficients of correlations of the best models of regression in the two directions varied from 0,85 to 0,91. The frequency histograms of the specifie gravity of plywood showed an unimodal homogeneous distribution, while the MOE and MOR showed an unimodal distribution with positive asymmetric skewness.

Keywords

• Componentes
• lâminas
• flexão estática em compensados
• <i>Pinus elliottii</i>.