Mechanical Testing Equipment Information

Last revised: January 24, 2025

Mechanical testing equipment covers devices used for adhesion, compression, drop (shock), tensile, vibration, and fatigue testing. The growing importance of quality control and assurance in production has contributed to an increasing demand for mechanical testing equipment with quality-control procedures existing on all production levels of many industrial markets. Mechanical testing for quality control serves two major purposes: product-endurance analysis and product-safety assurance. Understanding the strength and endurance of the product is beneficial to the end-user and to the supplier. Mechanical testing contributes to quality enhancement of a product because it enables manufacturers to test material characteristics before and after the final assembly stage. Because of the diverse nature of mechanical testing equipment, materials and structures of all sizes can be quality tested. Mechanical test methods include user interface options, display options, additional output options, and environmental parameters.

Types of Mechanical Testing Equipment

Specific mechanical tests include:

Features

  • ASTM defines adhesion as the state in which interfacial forces, which may consist of valence forces, interlocking action, or both, hold two surfaces together. Adhesion is one of the most important properties of a thin film system.
  • Compression testing can be performed on materials for a variety of purposes. Depending on the material type, compressive properties can be dramatically different than tensile properties.
  • Tests that characterize material performance under constant strain or stress conditions fall into the category of creep and stress relaxation. These tests can provide important information as to material or component properties under longer-term conditions.
  • Drop mechanical testing is also called shock testing; it is often performed as part of a hardware qualification or design process. Information obtained during shock testing can improve the survivability of products as well as verify that they will perform properly in service. 
  • Ductility may also be called flex or bend testing. Ductility is the ability to undergo plastic deformation in tension or bending before fracturing. 
  • Fatigue testers may also be called dynamic testers. Fatigue testers measure the fatigue resistance, or resistance to failure, of materials under controlled conditions of cyclic deformation. 
  • The two most commonly used methods of impact testing are Charpy and Izod. Impact tests measure the energy absorbed by the specimen before it breaks, a quantity composed of several energy contributions, including energy absorbed by the impact machine through vibrations after initial contact with the specimen and loss in pendulum energy (in pendulum impact tests) when the hammer strikes the specimen as well as the total energy consumed by specimen deformation and fracture. 
  • The shear strength is defined as the maximum stress that a material can withstand before failure in shear. Calculation of shear strength depends upon the test method. 
  • Tensile mechanical testing represents the most common type of test for materials and products. Characterizing and reporting tensile test properties is a basic need in most labs from QC to R & D. 
  • Vibration test systems are used to evaluate products and packages for design purposes as well as to simulate the vibration effects of product transportation.

Specifications

User interface options for mechanical testing equipment include local interfaces that are analog or digital, computer interfaces, serial or parallel communications, and application software. Display options for mechanical testing equipment include analog meters, digital readouts, and video displays. Additional output options include analog voltage, pulse signal, analog current, and switch or relay. Important environmental parameters to consider for mechanical testing equipment include operating temperature and operating humidity.

Mechanical Testing Equipment FAQs

What are the key differences between tensile and compressive testing in mechanical testing?

The key differences between tensile and compressive testing in mechanical testing can be summarized as follows:

Nature of the Test

Tensile Testing: This test involves stretching a material by pulling it apart to determine its tensile strength, elongation, and other properties. The material is subjected to a uniaxial stress state, and the test is typically performed using a machine with two jaws, one of which moves away from the other at a controlled rate, known as the strain rate.

Compressive Testing: This test involves squeezing or compressing a material by applying aligned opposing forces. It is often performed using a hydraulic system that forces a ram down on a cylindrical sample, causing it to "barrel" outward until failure.

Materials Tested

Tensile Testing: Commonly used for metals, which generally have similar strength in tension and compression. It is more prevalent for materials that are expected to experience tensile loads in their applications.

Compressive Testing: More common for ceramic materials like concrete, cement, and stone, which are typically stronger in compression than in tension. These materials are often used in applications where they are subjected to compressive loads.

Purpose and Outcomes

Tensile Testing: Aims to determine the material's tensile strength, elastic limit, elongation, and yield or breaking point. It helps in understanding how a material will behave under tensile loads.

Compressive Testing: Measures stress, strain, and deformation under compressive loads to assess whether a material is suitable for specific applications or if it will fail under specified stresses.

Equipment and Setup

Tensile Testing: Involves a machine with clamps that hold the specimen, which is then stretched at a constant rate until it breaks.

Compressive Testing: Often uses a hydraulic system to apply compressive forces, and the test setup may vary depending on the material and the specific requirements of the test 

What is the equipment used in tensile and compressive testing?

In tensile and compressive testing, the equipment used is designed to apply specific types of forces to materials to evaluate their mechanical properties. Here's a detailed look at the equipment used for each type of test:

Tensile Testing Equipment

Tensile Test Machine

Structure: It typically consists of two jaws or clamps. One jaw is fixed, while the other moves away at a controlled rate, known as the strain rate, to stretch the material until it fails.

Functionality: The machine measures the material's response to tension, including its tensile strength, elongation, and yield or breaking point.

Sample Preparation: The test piece is usually cylindrical with a constant cross-section and grip ends machined to avoid stress concentrations. Fine marks are made for measuring elongation.

Compressive Testing Equipment

Compression Test Machine

Structure: Often uses a hydraulic system that applies compressive forces by forcing a ram down on a cylindrical sample.

Functionality: The machine measures stress, strain, and deformation as the material is compressed. It is particularly useful for materials like ceramics, which are stronger in compression than in tension.

Sample Behavior: As the load increases, the cylindrical sample may "barrel" outward until failure.

Both types of testing machines are equipped with control systems to detect when the material has failed and to stop the application of load safely 

What are the types of materials typically tested using compressive testing?

In compressive testing, materials are subjected to forces that squeeze or compress them to evaluate their mechanical properties. The types of materials typically tested using compressive testing include:

Ceramics

Concrete: Often used in construction, concrete is tested for its compressive strength because it is much stronger in compression than in tension.

Cement: Similar to concrete, cement is tested to ensure it can withstand compressive loads in building applications.

Stone: Used in various structural applications, stone is tested for its ability to bear compressive forces.

Metals

While metals are generally strong in both tension and compression, compressive testing can still be performed to understand their behavior under compressive loads, especially in applications where they are subjected to such forces.

Building Materials

Asphalt: Used in road construction, asphalt is tested for its compressive properties to ensure durability and performance under traffic loads.

These materials are often chosen for compressive testing because they are commonly used in applications where they are subjected to compressive loads, such as in construction and infrastructure projects.

What is the significance of strain rate in tensile testing?

The significance of strain rate in tensile testing is crucial for understanding how materials behave under different conditions.

Definition of Strain Rate

The strain rate is the speed at which a material is deformed during a tensile test. It is the rate at which the distance between the jaws of the tensile test machine increases as the material is stretched.

Impact on Material Behavior

Materials can exhibit different mechanical properties when subjected to different strain rates. For instance, some materials may become more brittle or ductile depending on how quickly they are stretched. This means that the strain rate can significantly influence the tensile strength, elongation, and other properties of the material.

Importance in Material Comparison

When comparing materials, it is essential to specify the strain rate because it ensures that the comparisons are valid. Different strain rates can lead to different results, so maintaining a consistent strain rate is necessary for accurate comparisons.

Applications and Testing Standards

In engineering applications, understanding the strain rate is vital for predicting how materials will perform under real-world conditions, where the rate of loading can vary. Testing standards often specify the strain rate to ensure consistency and reliability in the results.

How do tensile and compressive properties affect material selection in engineering applications?

The tensile and compressive properties of materials significantly influence material selection in engineering applications. Here's how these properties affect the decision-making process:

Understanding Material Behavior

Tensile Properties: These properties, such as tensile strength, elongation, and yield point, indicate how a material behaves when subjected to stretching forces. Materials with high tensile strength are chosen for applications where they will experience pulling or stretching forces, such as cables, ropes, and structural beams.

Compressive Properties: These properties, including compressive strength and deformation, are crucial for materials that will be subjected to squeezing or compressive forces. Materials like concrete and stone, which are stronger in compression, are selected for applications such as columns, foundations, and pavements.

Application-Specific Requirements

Structural Applications: In structures, materials are often selected based on their ability to withstand both tensile and compressive forces. For example, reinforced concrete uses steel rebar to handle tensile forces while the concrete itself handles compressive forces.

Safety and Reliability: Understanding the tensile and compressive limits of materials ensures that they will not fail under expected loads, which is critical for safety and reliability in engineering designs.

Material Selection Process

Comparative Analysis: Engineers compare the tensile and compressive properties of different materials to determine the best fit for a specific application. This involves considering the strain rate, as materials can behave differently under varying rates of loading.

Standards and Specifications: Material selection is often guided by industry standards that specify the required tensile and compressive properties for certain applications, ensuring consistency and performance.

Mechanical Testing Equipment Media Gallery

References

GlobalSpec—Safe Transport of Nuclear Fuel Rods Is Subject to ORNL Device

GlobalSpec—Structural Components: Mechanical Tests and Behavioral Laws

GlobalSpec—How strain, stress and other materials properties are measured

GlobalSpec—Understanding stress vs strain in materials

GlobalSpec—The Twists, Turns, Trials and Tribulations of Your Average Material

GlobalSpec—Mechanical Testing Services Information


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