What Is an Impact Tester?
An impact tester is a testing machine used to perform impact tests.
In impact testing, we confirm that the products we use have sufficient strength when subjected to impact, and in the event of breakage, we confirm the type of breakage that occurs. Some of the products we use in our daily lives have components that are used under impact loads or are subjected to impact due to accidental factors. To maintain product safety, it is essential in product development to evaluate the durability and breakage of products under impact loads.
There are two main categories of impact testing. The other is the impact strength of the product itself and how it breaks when subjected to impact.
Most of the tests standards are classified into the former category. In these tests, the amount of distortion, expansion, shrinkage, flatness, surface cracks, etc. are measured when a sample is subjected to impact.
Uses of Impact Testers
Impact testers are used to evaluate whether or not, or to what degree, a product, its components, or its materials have the specified impact strength. Impact Testers are used to verify the impact strength of metal materials and resins, and the strength of industrial products to impact loads.
Smartphones, which are indispensable in our daily lives, are not usually subjected to impact loads. However, it is possible for them to be dropped by accident. Impact Testers are used to confirm that a product will not break even if it is accidentally dropped, and to determine the type of breakage that may occur.
Principles of Impact Testers
There are various impact testers, each of which has its own testing machine. The common principle of the impact tester is that the test specimen and test method are specified to ensure repeatability of the test.
Impact testers apply an impact load to the test object, and it is important that the same conditions are applied when the test is repeated. While the impact test may result in significant plastic deformation or even cracking of the test object, slight differences in the impact load can significantly alter the results.
Variations in the test object itself may also have an effect. Therefore, the test method is defined from the viewpoint of how the same impact load can be repeatedly applied and how the test can be performed with high reproducibility.
Other Information on Impact Testers
Types of Impact Tests
The following three types of impact testing are typical.
1. Izod Impact Tester
In the Izod impact test, one side of a specimen is fixed and the other side is impacted to measure the impact value. One side of the incised specimen is fixed and impacted with a pendulum-type hammer.
The evaluation is made by the angle at which the hammer impacting the specimen is lifted by inertia. This test method is mainly used to evaluate the toughness and tenacity of materials.
2. Charpy Impact Tester
Charpy impact test is a test to evaluate the brittleness of materials. Fragility refers to brittleness. It is evaluated by fixing both ends of a specimen piece with a cut in the center, applying an impact to the center of the specimen with a fixed force, and measuring the amount of deformation of the specimen at that time and the magnitude of the impact value at the time of failure.
At the time of breakage, the energy absorbed by the specimen at the time of breakage is calculated using the potential energy of the hammer that jumped up upon impact.
3. High Acceleration Impact Tester
High acceleration impact testers are testers that measure the degree to which a product is damaged by an impact by fixing the product to be measured on an impact table and generating a waveform of impact acceleration on the table. It is used for electronic devices such as smartphones and laptop computers.
Other tests include:
- Plastics – tensile impact strength test
- DuPont drop impact test
- Dart impact test