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:

• adhesion or bond testers
• compressive testers
• creep and stress relaxation testers
• drop or shock testers
• ductility testers
• fatigue testers 
• impact toughness testers
• shear testers
• tensile testers
• vibration testers

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.

Related Information

CR4 Community—Testing for Mechanical Properties of Cementious Products

Engineering360—Safe Transport of Nuclear Fuel Rods Is Subject to ORNL Device