Load Cells in Materials Testing

Materials testing is the process of measuring the physical characteristics and behavior of objects or
substances (metals, plastics, etc.) under varying sets of conditions. The purpose of this testing is to
ensure the safety and reliability of products, structures, and constituent materials. Strain gauge load
cells are essential components in the materials testing process. Used to measure the force applied to a
material during testing, load cells play a central role in determining the strength, flexibility, elasticity,
ductility, and durability of materials.

Materials Testing with Load Cells

Materials testing incorporates the use of specialized machines to perform each type of test. Load cells
are key components of these machines. Using varying techniques, a controlled force is applied to the
material being tested. It is the load cell component of the machine that provides force measurement
data for the test. The parameters of the test force depend on the material and the characteristic being
measured. Some forces include tension, compression, shear, and torsion.

Common Types of Materials Testing

The most common types of tests include: tensile, compression, bending/flexural, torsion, fatigue,
impact, and peel testing. The choice of a suitable load cell for each type of test depends on the type of
material being tested and the desired accuracy level.

Tensile and Peel Testing

In tensile and peel testing a tension load cell such as a tension link or S-type would be used to measure
the amount of tension force applied to the material being tested. The results of tensile tests can be used
to determine the material’s tensile strength, tensile modulus, elongation, and Poisson’s ratio. Peel
testing is used to ascertain the initial peak force, average force over the seal, and peel strength of adhesive
materials.

Compression Testing

Compression load cells are used in compression testing and impact testing to measure the force applied
to a material as it is compressed. Such load cells include beam, canister, button, or donut load cells.
Compression testing determines the test material’s elastic limit, proportional limit, yield point, yield
strength, and compressive strength. Impact testing measures the ability of an object to resist high-velocity
loading and determines the amount of energy absorbed in fracturing the material.

Shear Web and Torsion Testing

Shear web and torsion load cells are used in torsion tests, which determine the properties of materials
while under stress from angular displacement. Properties measured via torsion testing are modulus of
elasticity in shear, yield shear strength, ultimate shear strength, modulus of rupture in shear, and
ductility. Depending on the style of the machine being used, compression, tension, or universal load cells
may also be incorporated.

Bending and Flexural Testing

Bending/flexural testing and fatigue testing can involve any of the above-mentioned load cells (tension,
compression, universal, torsion, shear) depending on the testing machine or device being used. Bending
and flexural testing are used to determine flexural strength, flexural modulus, modulus of rupture, and
maximum fiber stress. Fatigue testing applies cyclic loading to an object or material to assess how it will
hold up under actual use.

Regulations and Measurement Accuracy

In order to adhere to industry regulations and standards, measurement accuracy is one of the most
critical aspects when choosing a load cell for materials testing. Electronic strain gauge load cells are
preferred for their dynamic range, reliability, and cost-effectiveness. Load cells must be calibrated
regularly to ensure accurate readings, and must be appropriately mounted to avoid any errors in the
measurement process.

Assisting OEM’s with Materials Testing

Load Cell Central has assisted OEMs with materials testing for over three decades by supplying load
cells and custom-designed weighing systems. Load Cell Central’s motivated staff, decades of experience,
and manufacturing flexibility ensure that you can always turn to a custom load cell for even the most
difficult applications. Customizable capacities, dimensions, materials, connectors, and outputs ensure
you get a product that fits seamlessly into your existing system.