Although materials testing is a well established technique, there are a multitude of tests that can be carried out using a universal materials testing machine. Sophisticated control software allows these tests to be carried out completely automatically and to internationally recognized standards, but for those establishing testing programmes or carrying out research, a more detailed understanding of the tests is necessary.
Finding out what these tests measure can be approached either from the instrumentation route (i.e. looking at the information made available by the supplier) or by the industry route, where an in depth understanding of the properties of specific materials intrinsically include an understanding of the measurement principles and methods. This article looks at information available from steeluniversity.org, a website which provides advanced, sophisticated and highly interactive e-learning resources on steel technologies and Lloyd Instruments, a leading manufacturer of universal material testing machines.
steeluniversity.org, is an award-winning, website packed with useful information on the mechanical properties of steel. steeluniversity.org is an on-line initiative from the World Steel Association. Produced in collaboration with MATTER (Materials e-learning Resources) and the University of Liverpool, this site provides a comprehensive package of highly interactive and informative e-learning resources on steel technologies, covering all aspects of iron and steelmaking processes through to steel products, their applications and recycling. In addition, it offers an opportunity to study and apply the basic scientific, metallurgical and engineering principles, thermodynamics and kinetics that underpin the production and use of steel. The site is aimed at undergraduate and graduate students and their teachers and lecturers and also employees, mainly at the graduate level, and their trainers in companies in the steel industry supply chain.
The site features a major section on the evaluation of mechanical properties of steel, which includes comprehensive coverage of tensile testing both from a theoretical and practical viewpoint. Commercial material testers are illustrated on the site by the single column LFPlus (1kN) and twin column LS100Plus (100kN) and LR300K (300kN) materials testing machines from Lloyd Instruments.
Figure 1. The single column LFPlus (1kN) from Lloyd Instruments.
Figure 2. The twin column LS100Plus (100kN) from Lloyd Instruments.
Figure 3. The LR300K (300kN) from Lloyd Instruments.
Tensile Testing of Steel
steeluniversity.org provides a comprehensive section on tensile testing. Tensile testing is one of the most common testing methods and is used to determine the behaviour of a sample while an axial stretching load is applied. Tensile testing is used in the steel industry to determine whether the steel conforms to the required specification(s). Areas covered in this section include:
- Measurement of Strain
- Determination of Yield Point
- Effects of Strain Rate
- True Stress - True Strain
- Work Hardening and Necking
- Work Hardening and True Stress - True Strain Curves
- Work Hardening and Ductility
- True Stress/Strain
- True Stress/Strain Curves and Ductility
- Microstructural Effects and Ductility I
- Microstructural Effects and Ductility II
- Microstructural Effects and Ductility III
- Ductility and Elongation
The section also provides practical information on how to conduct a tensile test.
Lloyd Instruments Materials Testing Systems
Lloyd Instruments is a global supplier and manufacturer of testing equipment and data analysis software with many years experience in the field of materials testing. Its comprehensive and informative website provides a lot of useful information for people wanting to understand more about materials testing. A glossary of terms provides simple definitions of a lot of the terminology used in materials testing. Another helpful resources is the ‘test type’ section. This covers all the tests listed below and explains the test and highlights the common results available from Lloyd Instruments™ material testing systems within the particular test type.
- Adhesion Testing / Adhesives Testing
- Bending Tests
- Bond Strength Testing
- Break Strength Testing
- Coefficient of Friction Testing
- Compression Testing
- Creep Testing
- Crush Resistance Testing
- Deformation Testing
- Delamination Strength Testing
- Dry Strength Testing
- Ductility Testing
- Elastic Limit Testing
- Elongation Testing
- Flexural Strength Testing
- Friction Testing
- Modulus of Elasticity Testing
- Peel Strength Testing
- Puncture Strength Testing
- Rupture Testing
- Shear Strength Testing
- Stress Relaxation Testing
- Tear Resistance Testing
- Tear Strength Testing
- Tensile Strength Testing
- Toughness Testing
- Young's Modulus
Of course many of these tests can be applied to a wide range of different materials and are not restricted to the testing of steel, and customers themselves can play a major role in the development of system solutions.
International Standards Relating to Materials Testing
Numerous tests carried out need to meet international testing standards (ASTM, ANSI, ISO, EN, BS, DIN, etc.). Many materials testing machines operate under software control, and Lloyd Instruments’ NEXYGENPlus material test and data analysis software features a large built in library of test methods covering ASTM, DIN, EN, ISO and other standards, making it extremely easy for users to access these tests. For specialist testing, test creation wizards are also included for tension/compression test, tear and peel test, cycling test, flexural test, friction test and the user configurable test for multi-stage testing.
Internet resources provide lots of valuable information to help with understanding specific material tests. Sites such as steeluniversity.org demonstrate essential basic principles and theoretical concepts, and provide a powerful supplement to more traditional learning. Material testing machine manufacturers also offer useful information.
This information has been sourced, reviewed and adapted from materials provided by Lloyd Instruments Ltd.
For more information on this source, please visit Lloyd Instruments Ltd.