1. OBJECTIVE
The torsion experiment consists of determining the properties of materials when subjected to torsional stress. This test also demonstrates the use of a caliper to obtain the dimensions of the test piece. The experiment will be carried out using a torsion testing machine containing a reducing flywheel to apply the touch to the specimen. The digital system for obtaining measurements in the experiment is coupled to the torsion testing machine. As part of the activities, you must measure the initial and final dimensions of the test piece, in order to verify the variations suffered by it and determine the torsional resistance limit, proportionality limit and the elasticity and shear moduli for the test pieces. various materials tested.
At the end of this experiment, you should be able to:
Determine the torsion resistance limit of the materials;
Analyze the torsion resistance limits of materials, identifying the particular characteristics of each material that influence the resistance limit values presented;
Build and interpret the stress x deformation graph of materials for torsion tests;
2. WHERE TO USE THESE CONCEPTS?
The torsion test is important for obtaining and understanding the mechanical properties of a material. Through this test, it is possible to obtain information regarding the maximum shear stress, deformation (shear) of the body when subjected to torsional effort, modulus of elasticity and mainly the torsional modulus and stiffness of the material. This information is extremely important for the use and selection of materials in different areas of engineering, especially civil construction, which involves designing buildings, bridges and other structures.
3. THE EXPERIMENT
In this test you will make use of a torsion testing machine, measuring system, test specimens and caliper. The torsional resistance presented by the material is determined through the torque applied to it. The caliper is used to measure the dimensions of the specimen before and after carrying out the experiment.
Torque is applied to the specimen by turning the reduction wheel. The applied torque generates twisting of the specimen until it presents partial or total rupture. The rotation angle of the part throughout the test is measured by the measuring system. Upon reaching failure, the test piece is removed from the machine so that its dimensions can be measured.
4. SECURITY
The experiment was designed not to bring physical risks, so you will use objects that are not very harmful and light. Even with these precautions, the use of personal protective equipment (PPE) is extremely important for safety during experiments. In this experiment, the use of a lab coat is recommended.
5. SCENARIO
The bench for carrying out this experiment will have: torsion testing machine, test specimens, caliper and test data acquisition system.