DEVELOPMENT AND USE OF SOFTWARE FOR MEASUREMENT OF DEFORMATION IN EXTRUDED PRODUCT.
Gilmar Cordeiro da Silva1; Luiz Eduardo Silva Carneiro1; José Rubens Gonçalves Carneiro1; Pedro Paiva Brito1; Tarcísio José de Almeida1
1 Pontifícia Universidade Católica de Minas Gerais
doi:10.20906/CPS/COB-2015-1173
Resumo
Extrusion is the process by which a metal block is reduced in its cross-section causing the material to flow through an orifice in the die under high pressure. The basic operations are backward-extrusion, forward-extrusion and radial-extrusion. In the backward process of extruding a punch penetrates the sample and the material is forced to shear heterogeneously in regions close to the penetration channel. This work aims to evaluate the deformation profile in three different regions in the process of indirect extrusion of steel ABNT1010 drawn. A machining technique was used for marking circular grid pattern in the test specimens and the implementation of a calibration image analysis software based on the calculation of the transformation matrix between the coordinate system associated with the image plane, obtained by a vision camera, and the world coordinate reference system. The measures of the deformations were performed manually and automatically. For manual measurements we used a profile projector in order to compare with the measurement done automatically by the software. The implemented algorithm is efficient for images where the acquisition phase was efficient. Satisfactory results were obtained for all analyzed regions and the determined strain profile showed consistency with the literature. However, the algorithm was sensitive to noise near the edges of the marks and the lack of contrast between the marking and work piece. Finally, the results were compared and the automatic measurement uncertainty was known.
Palavras-chave: Backward-extrusion; Strain Analysis; Computer vision; Image processing