The compression test, or compression test, is performed by applying forces to a material that push it inwardly from the opposite side and cause the material to jam, crush or flatten. When performing this test, the test sample is generally placed between two plates distributing the applied load across the entire surface area of the two opposite faces, which are then pushed together by a universal testing machine which causes the sample to flatten. The compressed test sample generally shortens in the direction of the applied forces and expands in the direction perpendicular to the force. The compression test is essentially the opposite of the commonly applied tension test.
The main purpose of compression tests is to determine the behavior and response of a material under a compression load by measuring fundamental variables such as stress and deformation. With the compressive force applied to the material, the elastic modulus of the material is determined between the compressive strength, yield strength, final strength, elastic boundary and other parameters. By understanding these different parameters and the values associated with a particular material, it is understood whether the material is suitable for certain applications or whether it will fail under certain stresses.
Generally, a compression test for a material requires at least two reciprocal forces applied to the surface of the sample to compress the sample. However, apart from this basic requirement, there are many different applications involving a combination of different variables. For example, more common compression tests include forces applied to multiple axes of the sample and testing the sample at high and low temperatures. The main compression test examples are uniaxial, biaxial, triaxial, cold temperature, high temperature, fatigue and creep tests.
The materials subjected to compression tests are those which generally have a compressive force considered to be high and a tensile force which is considered to have a lower value. In fact, any material may somehow experience compression forces depending on the area to which it is applied. For example, these tests are applied for composites, concretes, wood, stone, brick, mortar, polymers, plastics, foam and metals.
There are a number of compression testing methods developed by the American Testing and Materials Organization (ASTM) and the International Organization for Standards (ISO). A few of these standards are as follows:
- ASTM D575-91 (2018) Standard test methods for rubber properties in compression
- ASTM D6641 / D6641M Standard Test Method for Pressure Properties of Polymer Matrix Composite Materials Using Combined Loading Compression (CLC) Test Fixture
- ASTM D695-15 Standard Test Method for Pressure Properties of Hard Plastics
- ASTM E9-19 Standard test methods of compression testing of metallic materials at room temperature
- TS EN ISO 14126 Fiber reinforced plastic composites - Determination of plane compression properties
- TS EN ISO 1856 Flexible, porous polymeric materials - Determination of crushing rate under pressure
- TS EN ISO 844 Hard porous plastics - Determination of compression properties
In short, the compression test is one of the most important tests to determine the behavior of composite materials. The mechanical properties of these materials can be altered by applying a load, but the compression properties are difficult to measure because the design of the material relates to the compression properties of the material caused by the applied load. It is necessary to calculate the stress and strain relationship and use this value to determine the compressive strength and modulus of elasticity of the material.
EUROLAB also provides compression testing services for a wide range of laboratory services. Thanks to these tests, enterprises receive more efficient, high performance and quality testing services and provide safe, fast and uninterrupted service to their customers.
In addition to the compression testing services provided within the scope of laboratory services, EUROLAB also provides other testing services.