Determinação de propriedades elásticas e de resistência dos compensados estruturais / Gabriel de Oliveira Ribeiro.

Dissertação (mestre) - Universidade de São Paulo, 1986

In this study it was determinated the elastic constants and strength properties of plywood. It was used a test method which is proposed. According to this method it was executed the following tests: tension, compression, bending and plate twisting. The test specimens were made of structural plywood and their thicknesses were: 4mm, 8mm, 12mm, 15mm. The experimental results provided the folowing elastic constants: the effective moduli of elasticity in the two principal directions Ex and Ey, shear modulus (Gxy), Poisson's ratios (vxy andvyx), and the strength properties of tension, compression and bending. The elastic constants of orthotropic plates are relate to the compliances Sij of the equations for the stress-strain relationship, so the compliance matrix was determinated. Also it was verified by statistical analysis the influence of the thickness (h) of the plates in the values of the effective elastic properties and in the effective strength properties. The elastic constants of orthotropic plates are relate to the compliances Sij of the equations for the stress-strain relationship, so the compliance matrix was determinated. Also it was verified by statistical analysis the influence of the thickness (h) of the plates in the values of the effective elastic properties and in the effective strength properties. The comparison of the Young's moduli determinated by tension and compression tests showed that they are stastically equivalent. It was noted a good tendency to an equivalence among the elastic and strength properties in the two principal directions of the strucutural plywood with thickness equal or greater than 8mm. The determination of shear modulus (Gxy) by three different procedures of twisting test showed equivalent. The choice of the simplest test method is therefore justified. The proposed method provides an easy way to determine all the parameters of plywood in order to be used in structures.