A tensile test is one of the most fundamental measurements in the engineering world. Although this test is common, there are several factors that must be considered before choosing tensile testing equipment for your specific application. Asking three simple questions can narrow down choices for a test machine, grips, fixtures and software.
Step 1—What is the specific type of test you want to perform and what material property/characteristic do you want to measure?
Tensile testing machines are also commonly referred to as Universal Testing Machines—they can perform an extremely wide variety of measurements on practically any material. Tensile stresses can be applied to materials in various ways to determine the tensile, shear, adhesion, and tear properties to name a few. Additionally, knowing what specific properties (ultimate tensile strength, yield strength, modulus of elasticity, shear strength, peel force, average tear force, etc) are of importance as they will dictate what grips, fixtures, and software packages may be necessary to perform your tests.
Step 2—What are the force requirements to perform the desired test?
Many tensile tests require increasing the applied force to the material until the material fails. Unless the mechanical properties of the material are generally understood and the sample geometry is clearly defined, this can be a difficult question to answer. Speaking with one of our experienced applications engineers will help in selecting a properly sized machine for your application. Tensile testing machine prices scale with force capacity, so it is important to select a machine large enough to accomplish your testing objectives while not being oversized and costly. Tensile testing machines should be sized according to your maximum force testing needs. If you have both high force and low force testing needs, multiple load cells may become necessary.
Step 3— What is the material/component geometry and deformation characteristics?
In addition to a wide range of force capacities, tensile testing machines come in a variety of system architectures and actuator displacement ranges. Single column machines are great for testing typical tensile specimens and small components, but may not offer adequate testing space for larger components. Actuator travel may become an issue when testing high elongation materials, such as rubber and other elastomers. To get an approximate value of how much actuator travel will be required, multiply the gage length used during testing by the percent elongation or strain at specimen failure. This will give you a minimum acceptable travel range, as deformation occurs in the entire length of material between the grips and not only the gage section.
By answering these three questions you are off to a great start in selecting a tensile testing machine for your application. Call one of our applications engineers today to discuss your specific testing requirements and receive suggestions on TestResources’ comprehensive offering of test machine, grips, fixtures, test accessories, software packages to meet your testing needs.