Avaliação de entalhe helicoidal de corpo de prova SNTT

Abstract

It is extremely important for the structural designer to know the mechanical properties of the chosen material and, for this, tests are carried out to determine the specific properties of each material. Currently, several new materials are developed around the world for various purposes, from semiconductor ceramics to 3D printing polymers. These new materials need to have their properties tested and validated accurately by testing replicable under different conditions. The Spiral Notch Torsion Test (SNTT) was developed to address the limitations of ASTM E399 standardized tests, which are often limited by the shape effect. In addition to overcoming the technical limitations of these tests, this new method also innovates in the format of the specimen, being able to miniaturize the specimens and test them in different atmospheric conditions or calculate the fracture toughness of materials that can’t be determined by another type of test, for example. This kind of miniaturization makes the test cost less compared to others. The objective of this project is to raise the costs to produce in low-volume the specimens used in the SNTT tests. These costs were based on processes carried out in the LTAD Laboratory of the Federal University of Uberlândia (UFU). It is estimated that the production of this body from an AISI 4340 steel bar, undergoing heat treatment to normalize the material properties and machining, costs approximately 𝑈𝑆$ 43. 00