You may ask why a compression test. This is a crucial step in the process of producing durable products. If you want to learn about compression tests then our guide is for you. It covers everything you need to know about compression testing from definitions, benefits, methods, and more. Our guide will teach you everything you need to know – let’s get started:
1. What is a compression test?
According to the survey, the compressive force is sometimes called the compressive force. Compressive forces occur when an object is squeezed inward by a physical force, causing it to compress. The relative arrangement of the object’s atoms and molecules changes in the process.
Depending on the type of material receiving the compressive force, adjustments can be temporary or permanent. Instead, depending on the location or placement of the object applying the compressive force, it may often have a different effect.
Compression testing, along with tensile and torsion testing, is one of the most important forms of mechanical testing. Compression testing is used to determine how a material will behave under an applied load, usually by applying compressive pressure to a test specimen (usually a cylindrical geometry or a cuboid) using a platen on a universal testing machine or a special grip.
Measure and map various material properties during testing and use stress-strain diagrams to determine quality. Compressive strength, elastic limit, proportional limit, yield point, and yield strength are among these qualities.
In fact, a compressive force test for any material can be defined as involving at least two forces opposing each other. For example, triaxial, biaxial, uniaxial, creep, temperature rise, and fatigue are examples of different compressive force tests that can be performed on materials.
Do you know? Typically, compressively tested materials have a particularly desirable high compressive strength and known lower values of tensile strength, such as tensile testing. Depending on the application, almost all materials are subject to compressive forces in one way or another, but metals, mortars, polymers, composites, concrete, wood, plastics, etc. are the most popular.
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2. Common compression test definitions and keywords
Common compression test definitions and keywords include the following, which will be introduced to you below:
- Compressive Strength: After gradual compression, the maximum compressive stress a material can sustain before yielding or breaking. Force per unit area is used to measure compressive strength.
- Compressive Stress: The compressive load per unit area of the smallest original cross-section. There may or may not be a correlation between compressive strength and compressive stress. Measurements of compressive stress are expressed in force per unit area.
- Compression Set: The reduction in the area of the gauge length of a test specimen due to an applied compressive force. Units of length are used to measure deformation.
- Compressive Strain: Ratio of compressive deformation to gauge length along the y-axis, or change in length per unit of original length. There are no units for strain since it is a ratio.
- Compressive Yield Point: The first point on a material’s compressive stress-strain curve where the strain value increases but the stress value does not increase. In terms of force per unit area, compressive yield strength is the stress at the yield point.
- Modulus of Elasticity: The ratio of the nominal stress below the proportional limit of a material to the corresponding strain. In modulus measurements, force per unit area is expressed.
- Poisson’s Ratio: Ratio of transverse strain to axial strain. Poisson’s ratio is a dimensionless ratio.
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3. Application
- On rigid surfaces applied to objects.
- Applied to the spring.
- on elastic material.
- Applied to rigid materials.
4. Compression force measurement
In the Standard International System of Units, compressive force is usually measured in Newtons (N). In physics, it is defined as a unit of force that causes a mass of 1 kilogram to accelerate by 1 meter per square second (m/s 2 ).
In the United States, traditional units of measurement include pound-force (lbF) and newton (N), while in most of the rest of the world, newton and kilogram-force (kgF) predominate. To ensure compliance with ISO, ASTM, or other international standards, a compression test procedure can be defined, or it can be developed in-house to achieve other goals.
However, when configuring your system, you must consider the shape and size of your sample, the expected maximum force required, line speed, and the interpretation of your results.
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5. Benefits of compression testing
Compression testing can provide component and product durability and reliability as well as material data for your products, helping you and ensuring that your products meet best practice standards and that your finished product is fit for purpose. The results obtained from compression testing can be used in a variety of ways.
Here are some examples:
1) Determine batch quality
Mass production is a production process in which identical or similar products are manufactured together for various production runs of different sizes. The technology enables mass production of products and small to large-scale modifications to your products. Each batch goes through a stage of the production process before producing the next stage of the desired product. Therefore, compression testing plays an important role in ensuring the quality of your batches.
2) Determine consistency at the time of manufacture
You ensure consistency at all times by testing materials for compression during production. In order to study the mechanical properties, and the consistency of the produced components or materials, your mechanical tensile and compressive testing of the product is a key element.
3) Assist in the design process
You can evaluate the mechanical behavior of samples under compression to provide fundamental material property data. This is critical for us to evaluate component design and service efficiency. Of course, for a wide variety of materials, specifications for compressive strength values and methods for measuring these properties are defined in various standards.
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6. The importance of performing a compression test
You can perform compression testing at multiple stages of production to determine the authenticity and safety of materials, parts, and products. From strength testing of automotive windshields to durability testing of concrete beams used in construction, there are many possibilities.
Needless to say, this helps you demonstrate the durability of your product, thus gaining the trust of your customers. For example, when armor technical parts like windshields are compression tested, they tend to appear tough and virtually unbreakable, which helps you show that their ATV parts can be better than others. For example, just like the currently popular TPE pillow. When the pillow manufacturer tests it for compression, its rebound degree can be restored to the same as before. Then this product will certainly be loved by the majority of customers.
But how do you ensure that their product actually has tensile strength? It’s very easy! Compressive strength appears to be low for materials with high tensile strength. Similarly, high-compressive strength materials tend to exhibit poor tensile strength.
Compression testing is also applicable to porous materials such as metals, plastics, ceramics, composites, concrete, and corrugated materials such as cardboard. Often, these materials are used for load-carrying capacity, and their reliability under compressive forces is critical.
7. How to perform a compression test
Additionally, compression tests and many other tests are performed on universal testing machines. However, these machines are available in a variety of force capacities and sizes, ranging from 0.02 N to 2,000 kN. Most low-force testing is performed on tabletop equipment, while for higher-force applications a floor model frame is required.
Testing applications and accessories such as extensometers must be equipped with a universal testing machine. The type of material you are testing will determine the type of accessories required. A single machine can be modified to measure any sample within its force range by simply adjusting the device.
Additionally, compression testing can be performed in different ways. Compressive force tests were performed using test specimens, a universal testing machine, and a vernier caliper. Following international laboratory standards, the following steps are widely accepted.
- Measure the length and diameter of the sample with calipers or any other measuring instrument.
- Place the sample between compression plates. The moving headlight should be in the center when placed vertically.
- Give direction to the advancing head to apply the load.
- These loads and associated contractions were recorded at weight intervals.
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8. Compression test standard
Below are some common compression testing criteria that we have compiled for you.
- ASTM C109 – Compressive Strength of Hydraulic Cement Mortars: Standard Test Method
- ASTM D575 – Standard Test Method for Compressive Properties of Rubber
- ASTM D695 – Compressive Properties of Rigid Plastics: Standard Test Method
- ASTM D1621 – Standard Test Method for Compressive Properties of Rigid Foam Plastics
- ASTM D2412 – Using Parallel Plate Loading to Determine the External Loading Characteristics of Plastic Pipes
- ASTM D3574 (B1) – Testing Methods for Flexible Cellular Materials – Sheet-Form, Bonded, and Molded Polyurethane Foams
- ASTM D3574(E) – Test Method for Sheet, Bonded, and Molded Polyurethane Foams
- ASTM D3574(F) – Standard Test Methods for Flexible Cellular Materials – Sheet, Bonded, and Molded Polyurethane Foams
- ASTM D3574 (X6) – Testing Methods for Flexible Cellular Materials – Sheet-Form, Bonded, and Molded Polyurethane Foams
- ASTM D6641 – Standard Test Method for Measuring Compressive Properties of Polymer Matrix Composites Using Combined Loading Compression (CLC) Fixture
- ASTM D7137 – Compressive Residual Strength Test Method for Damaged Polymer Matrix Composite Panels
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9. Tensile vs. Compressive Testing: What’s the difference?
The following will introduce you to the difference between tensile testing and compression testing.
1) What is a tensile test?
Tensile testing is primarily used to measure how much force is required to break or deform a material under a tension-based load. Component properties such as tensile strength, yield strength, elongation, and modulus of elasticity are determined by this type of testing. During tensile testing, your material is stretched and monitored until it breaks.
Engineers then use insights found in tensile testing when designing components and structures that need to withstand certain levels of load or strain in tension-based applications, such as when components are fastened together with bolts and screws or other fastening solutions.
2) What is a compression test?
Compression testing measures the force required to deform or compress a material under a compressive load. During this test, we place the sample in a compression testing machine, which applies a constant load until a predetermined amount of deformation or breaking point is reached.
Compression testing determines important parameters such as compressive yield strength, ultimate compressive strength, and modulus of elasticity. Engineers then use this data to ensure that components used in compression applications, such as bridges or columns, can withstand the required stress levels without cracking or deforming.
3) When to use the tensile testing method instead of the compressive testing method
In general, tensile testing is more suitable for applications where tension is applied, while compression testing is more suitable for applications involving compression.
In conjunction with tension and compression testing, manufacturers can better understand how materials behave in tension-based applications or under compressive loads, ensuring their products and components meet quality and safety standards.
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10. Conclusion
What you need to know is that testing is an essential part of the production process for components used in all industries. Choosing the right test method is especially important for applications where failure could put your customers at risk, and it is the only way to prove the safety and reliability of your product. Plus, you’ll have an easier time spotting any potential issues early on if you run this type of testing on a regular basis during production. Armed with this foresight, Linkotest‘s engineers can quickly resolve any complex issue before asking more important questions.