Avaliação das propriedades físicas e mecânicas das madeiras de Itaúba e Cupiúba

Abstract

The knowledge of the physical and mechanical properties of wood is of key importance for us to know where each species can be employed. The woods used today mostly come from native forests, despite the wide use, little is known about its physical and mechanical characteristics. This study aims to characterize the properties of two native species of widely exploited and marketed Amazon, Mezilaurus Itauba (Meisn.) Taub. ex Mez (Itaúba) and Goupia glabra Aubl. (Cupiúba). The tests were performed in wood Technology Laboratory, located at the Federal University of Mato Grosso (UFMT) Campus Sinop, the wood was provided by local sawmills, which were made 80 bodies of the test piece for mechanical tests of parallel compression and bending static, and 40 bodies of the test piece to the physical properties tests (shrinkage, swelling, density and porosity). The dimensions of the bodies of the test piece followed the recommendations of NBR 7190/97 rules for physical and mechanical properties tests for the mechanical tests used the universal testing machine to obtain the module of resistance and modulus of elasticity (MOE and MOR) and the ultrasound PROCEQ trademark for laboratory use to perform the non-destructive testing by determining the dynamic modulus of elasticity (EMD), as for the tests of physical properties has been used a tank with water, where the samples were submerged for a period 30 days until they reached the fiber saturation point (PSF). The method of ultrasound was effective to correlate the MOR and MOE with Emd and can be used as an alternative method for obtaining the mechanical property values for the two species. It also observed the influence of porosity on physical properties such as shrinkage and swelling, and specifies the mass of influence on the results of the mechanical properties. The strength values (MOR and MOE) for the two species did not differ according to the average Tukey test at a significance level of 5%, thus enabling the replacement of one species by another in certain cases.