ASTM E9 is one of the leading international standards for evaluating the mechanical properties of metals subjected to compressive forces. In industries such as construction, automotive and aerospace, metallic materials are frequently exposed to compressive loads that can compromise their strength and integrity. ASTM E9 provides guidelines for determining the compressive strength of various metals, from steel to metal alloys, ensuring that materials can withstand intense stresses without breaking or deforming.
Purpose of ASTM E9
The main objective of ASTM E9 is to provide a method for measuring the mechanical properties of a metal when subjected to compression. This test is essential for determining parameters such as yield point, modulus of elasticity and compressive strength, all of which are crucial for ensuring structural safety in critical industrial applications.
Why is compression testing necessary in metal testing?
Compression on metals allows us to replicate the stresses to which materials are subjected in their practical applications. For example:
In construction, steel or reinforced concrete columns must continuously withstand compressive forces.
In the automotive and aerospace industries, components must withstand intense compression during operation, ensuring the integrity of the structure.
Knowing a metal’s ability to withstand such stresses allows designers to select the most suitable materials.
Materials and specimens tested according to ASTM E9
The metal specimens used in ASTM E9 compression tests can vary in shape and size depending on the specific requirements of the test. Usually, cylindrical specimens are preferred, as this geometry facilitates uniform application of the compression force. However, rectangular or flat specimens may also be used, depending on the test conditions and type of application.
Description of the compression test according to ASTM E9
The ASTM E9 test involves the application of an increasing axial force until the failure point of the material is reached. Here are the main steps of the test
- Specimen preparation: precise measurement of dimensions and cleaning of the surface with solvents, such as acetone, to remove grease and impurities that could alter the results.
- Specimen positioning: The specimen is placed between the machine’s compression plates, ensuring that it is centred to avoid eccentric loads.
- Force application: a progressive force is applied until the material is deformed or broken, recording relevant key parameters of the metal’s mechanical behaviour.
Compression testing machines
Compression testing machines can be hydraulically or electromechanically driven:
- Hydraulic machines: Cermac’s UTM-H series machines are ideal for testing large metal specimens due to their high load capacity.
- Electromechanical machines: provide more precise control over the speed of load application, making them perfect for testing more delicate metals or small specimens.
Both types of machines are designed to ensure accurate results and conform to ASTM E9 standards.
Specimen preparation and positioning in the machine
Careful preparation of the specimen is essential to obtain valid results. In addition to cleanliness, the specimen must be positioned concentrically between the compression plates to avoid non-uniform deformations that could affect the accuracy of the data.
Precise positioning of the specimen
To avoid errors, the specimen must be well centred between the compression plates. By using high-precision fixtures and a strain gauge to monitor length variations, reliable and consistent measurements can be achieved. For this type of measurement, the video strain gauge can be a crucial tool for performing strain measurements on particularly critical specimens.
Parameters measured in the ASTM E9 test
During the compression test, various physical parameters are recorded, including:
- Compressive strength: represents the maximum force borne by the material before fracture.
- Stress-strain curve: plots the trend of material strength in relation to strain.
An essential calculation is the engineering stress (σ), which is obtained by dividing the applied force (P) by the original specimen cross-sectional area (A).
Modulus of elasticity: definition and calculation
The modulus of elasticity is a crucial parameter calculated during the compression test. It indicates the stiffness of the material and represents the ratio between the change in tension and deformation during the elastic phase of the test, i.e. when the material deforms reversibly.
Data collection and analysis
The data collected during the test is analysed using advanced software, such as the Testing by Cermac system, which allows stress-strain curves to be visualised and results to be stored for future analysis. These tools allow data to be exported in formats compatible with other analysis software.
Compliance with International Standards
Cermac’s universal testing machines, designed to meet ASTM E9 standards, guarantee accurate and globally recognised results. This is fundamental for organisations operating in markets governed by stringent regulations, ensuring that the materials tested comply with international standards.
FAQ
What is the ASTM E9 compression test? The ASTM E9 test determines the mechanical properties of metals subjected to compression.
What materials can be tested with ASTM E9? The standard applies to various metals, including steel and metal alloys.
What equipment is needed for testing? You need a universal testing machine, a strain gauge and analysis software.
How is the compressive stress calculated? Compressive stress is obtained by dividing the applied force (P) by the original specimen cross-sectional area (A).
Why is the modulus of elasticity important in compression testing? The modulus of elasticity measures the stiffness of the material and its ability to recover its original shape after deformation.
ASTM E9 Compression Testing Solutions
Cermac offers a range of testing machines designed to perform compression tests according to ASTM E9. With its precision instruments and advanced software, Cermac supports companies in ensuring that materials meet international standards, providing reliable and useful results for industrial applications. Contact us today to find out more about our testing solutions and to request a free quote.
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