Velocimetria por imagem de partículas e correlação digital de imagens no estudo de deformações em ensaios de flexão estática em madeiras

Abstract

The mechanical characterization tests provide data on the behavior of the materials. The ability to resist or transmit effort without excessive deformation or mechanical failure defines the use of materials in the various engineering areas. The evaluation of a material can be done in a destructive and non-destructive way. Therefore, it is very important to know different methodologies of tests to evaluate the mechanical properties of the materials. The nondestructive techniques of particle image velocimetry (PIV) and digital image correlation (DIC) differ from conventional test techniques, as they allow indirect measurements without destroying or damaging the materials and structures in service. In the present work, the objective was to determine the deformations, elastic modulus and the deformation map in wood beams of Eucalyptus grandis and Pinus oocarpa using non-destructive testing techniques, PIV and DIC. For this purpose, the materials under study were subjected to static bending tests to obtain the deformation in the beam. By means of the statistical tests Fisher and Scott Knott, with 95% confidence level, it was observed that in all regions of analysis of deformation with the DIC technique, values were statistically equal to those found in the conventional method, which also occurred in some of the regions analyzed by the PIV technique. The average values of modulus of elasticity (E) found by DIC, PIV and conventional method, respectively, were for Eucalyptus grandis of 16,693,61 MPa, 15,713,57 MPa and 17,176,63 MPa and for Pinus oocarpa of 7,166, 27 MPa, 6,425.54 MPa and 7,224.98 MPa. It was concluded that the PIV and DIC test techniques are able to measure displacements in a static bending test and obtain the modulus of elasticity in wood beams, thus presenting potential for use in structures in service.