You may have seen those YouTube videos showing expensive cellular phones being subjected to various “stress” tests to find out how tough or fragile they are. While it’s true that the tests are a little bit unfair because the gadgets were not designed to experience such extremes, they nevertheless underscore the importance of materials testing.
Simply put, materials testing is done to find out if the material can withstand real-life wear and tear or how much stress it can handle. This is usually done by laboratories like JTL Services that offer mechanical testing services. Their gathered data will tell if a material is suited for a specific application.
This is particularly important especially in the automotive, aerospace, and biomedical industries where a materials failure can become a life-or-death situation.
Reasons for Failure
Out in the real world, devices, components, and tools suffer a structural failure that lessens their usefulness, or worse, causes them to break down. This can be hazardous to the user and those around them. These are the usual causes:
- Too much deformation – based on the elastic characteristics of the material, it has two types. Elastic deformation happens when there is either stable or unstable equilibrium in loading conditions. Inelastic deformation happens when load conditions cause fatigue, ductile fracture, and creep.
- Fracture – caused by stress and strain that happen alternately, this can cause cracks that can be further aggravated by additional stress or material defects.
- Wear – this can be found at the point of contact of components that bear the load.
Materials testing is usually done using two types of machines: electro-mechanical and servo-hydraulic. While both are used to test for metal and polymer properties, each has unique capabilities for different jobs. Electro-mechanical machines are used for static and rate-controlled loadings and are best suited to test metals, rubber, plastics, and elastomers.
Servo-hydraulic machines, on the other hand, are used to test for fatigue and dynamic properties. They can generate large amounts of force to test a material’s endurance.
There are different ways to test materials under varying load conditions. The results are then used as the basis to tell if a particular material is adequate for a specific function or not. This ensures that the final product will not fail and cause damage or injury.
To make sure materials will perform as expected, they can undergo any of the following tests:
- Fatigue testing – materials are made to undergo continuous loading to find out where damage will start and progress.
- Tensile testing – this determines the point at which a material such as a rope, beam, or wire will break if pulled with increasing force.
- Hardness testing – heat-treated surfaces are tested for conformance. It also finds out how different kinds of shape change or penetration can be resisted by solid matter where force is applied.
- Compression testing – tests the elastic and proportional limit, yield point and strength, and compression strength of materials under a compressive load.
Without testing, the integrity of a material that will be used for tools or gadgets can be compromised. Cell phones placed in the back pocket of pants that break can be at most a nuisance, but when we’re talking about car or airplane parts that fail during operation, that can mean disaster.