Why compression force testing you may ask? It’s a vital step in the process of producing durable products. Read further on what you should know and how the testing works.
What is Compression Force Testing?
Compression force, which is sometimes referred to as compressive force, happens when an object is pressed inward by a physical force, causing it to compact. The relative arrangements of the object’s atoms and molecules change in this process. The adjustment may be temporary or permanent depending on the type of material receiving the compressive force. On the contrary, there may often be different effects depending on the position or placement on the object where the compressive force is applied.
Compression testing, along with tensile and torsion tests, is one of the most significant forms of mechanical testing. A compression test is used to determine the behavior of a material under applied loads and is normally performed using platens or specialized fixtures on a universal testing machine by applying compressive pressure to a test specimen, typically of either a cylindrical geometry or a cuboid. Various material properties are measured and plotted during the test as a stress-strain diagram is used to determine the qualities. These qualities include; yield point, yield strength, elastic limit, proportional limit, and compressive strength.
A compression force test for any material can be defined as the involvement of, at least two opposing forces, aimed at each other. Triaxial, biaxial, uniaxial, creep, rise in temperature and fatigue are all examples of different compression force tests that can be performed on a material.
Usually, compression testing materials have a compressive strength that is particularly ideal to be high and a tensile strength that is known to be of lower value, for example, tensile test. Depending on applications, almost all materials are subjected to compressive force in one way or another, but metals, mortars, polymers, composites, concrete, wood, plastics, and among many others, are the most popular materials.
Examples of compression force application include:
- Upon a rigid surface applied to an object.
- Applied to a spring.
- Upon elastic material.
- Applied to a rigid material.
Compression Force Measurement
With the standard international System of Units, the compression force is usually in Newtons (N). In physics, it is defined as a unit of force that gives to a mass of one kilogram an acceleration of 1 meter per second squared, m/s2.
In the United States of America, traditional measuring units include pounds-force (lbF) and Newtons (N), whereas, in most of the rest of the world, Newtons and kilograms-force (kgF) dominate. To ensure compliance with ISO, ASTM, or other international standards, compression force test procedures can be defined, or the procedure can be developed in-house to achieve other objectives.
However, sample shape and size, maximum force expected required linear speed and interpretation of results must be taken into consideration when configuring a system.
Importance of Performing Compression Force Testing
Compression testing helps manufacturers at many stages of production to determine the authenticity and safety of materials, parts, and products. The possible applications can range from a car windshield strength test to a concrete beam endurance test used in building. Needless to say, this helps manufacturers to portray the durability of their products and in turn, gain the trust of their customers. For instance, when Armor Tech parts like windshields undergo compressions tests, they tend to show that they are tough and pretty much unbreakable, which helps the manufacturers to show that their all-terrain vehicle parts can be better than others.
But how do manufacturers ensure that their products are actually tensile? Simple! High tensile strength materials appear to exhibit low compressive strength. Similarly, high-compressive strength materials tend to demonstrate poor tensile strength. Therefore, on porous materials such as metals, plastics, ceramics, composites, concrete and corrugated materials like cardboard, compression testing is also used. These materials are often used in a load-bearing capacity where their reliability under compressive forces is vital.
Benefits of Compression Force Testing
Compression testing provides components and products’ durability and reliability, data on materials, helping manufacturers ensure they meet the best standard of practice and their finished products are fit for purpose.
The result gotten from a compression force test can be used in many ways.
The following are a few examples:
- To determine the batch quality
Batch production is a production process where identical or similar products are manufactured together for various production runs of different sizes. The technique enables products to be bulk-produced in batches with micro-scale to large product modifications. Before the next stage of production of the desired product, each batch goes through a single stage of the production process. Compression force testing plays a major role to ensure batch quality.
- To determine consistency when manufacturing
With compression force testing of materials during production, consistency is always a sure bet. To investigate mechanical properties, consistency of the elements or materials produced, mechanical tensile and compression tests are key elements.
- To aid in the design process
The assessment of a sample’s mechanical behavior under compression conditions can be performed to provide basic material property data. This is essential for the evaluation of component design and service efficiency. For a vast variety of materials, the specifications for compression strength values and the methods for measuring these properties are defined in various standards.
How to Perform Compression Force Testing
Compression force tests and many other tests are conducted on a Universal Testing Machine. Several force capacities and sizes and ranging from 0.02 N to 2,000 kN are available for these machines. The majority of low force testing is experimented on a tabletop device, while for higher force applications, floor model frames will be required.
Testing applications and accessories, such as extensometers, must be fitted with a universal testing machine. The type of material being tested will decide the type of accessories necessary. And a single machine may be modified by simply adjusting the device to measure any specimen within its force range.
Compression force testing could be done in different ways. A specimen, Universal Testing Machine, and Vernier Calliper are used to perform compression force testing. Following international laboratory standards, the following steps are well accepted.
- Measure the length and diameter of the specimen with a Vernier caliper or any other measuring instrument.
- Place the specimen between the compression plates. It should be at the center for the moving head to be placed vertically.
- Apply the load by giving direction to the advancing head.
- These loads and related contractions are recorded at an interval of weight.
