Projeto de equipamento para geração de pré-trincas em amostras cilíndricas com entalhe helicoidal

Abstract

The interest in materials analysis is higher than ever, to define specific properties of each material, with minimal costs and major reliability on results, is extremely important to engineering. Nowadays, there are many capable tests that define steel, ceramic, polymers specific characteristic. The newest test in development that identifies fracture toughness is SNTT (“Spiral Notch Torsion Test”), it uses small helical notch cylindrical specimens. To certify that the test is efficient, the specimen must have an initial crack, which simulates a natural defect on the material. So, this project aims the development of a machine that is able to open a pre crack on specimen. To construct the machine some consideration was made, first the size of samples and equipment components was defined. In order to verify the established dimensions, a stress analysis considering fatigue was made. Besides calculation’s memorial, a 3D simulation was created, using the software Autodesk Inventor R to compare both results. After the dimensional verification, a selection of components such as bearings, keyways and structure profile was made. Therefore, the results obtained were satisfactory, all the components of the mechanism resist the critical forces, besides they can be easily found, manufactured and assembled.