Jump to the content of the page

Impact Testing

What is impact testing?

Impact tests are short-term tests which provide information on the failure behavior of materials or components subjected to rapid loading and at varying temperatures. The testing systems used for these tests are either pendulum impact testers or drop-weight testers.

Because many materials used for a number of different applications on a daily basis are subjected to fluctuating temperatures, and since the fracture or failure behavior also depends on temperature, these materials must often be tested in their entire operating temperature range. These tests are used to indicate at what temperature and to what extent the material becomes brittle.

The example diagram shows that the decrease in strength of mild steel at -40 °C is 25 % in relation to the strength at 0 °C. Plastics display a similar behavior, but generally considerably more pronounced. Impact tests are also frequently carried out on plastics at various temperatures.

Impact test with pendulum impact testers Impact test with drop weight testers Impact test with high-speed testing machines

Impact testing with pendulum impact testers

Charpy impact test
to Charpy impact test
Notched Charpy impact test metals
ISO 148-1
to Notched Charpy impact test metals
Charpy and Izod notched impact test metals
ASTM E23
to Charpy and Izod notched impact test metals
Notched Charpy impact test on plastics
ISO 179-1, ISO 179-2
to Notched Charpy impact test on plastics
Izod impact resistance plastics
ASTM D256
to Izod impact resistance plastics
Notched Izod impact strength plastics
ISO 180
to Notched Izod impact strength plastics
Tensile impact test plastics
ISO 8256, ASTM D1822
to Tensile impact test plastics
Dynstat bending test and impact test
DIN 53435
to Dynstat bending test and impact test

What is the difference between Charpy and Izod impact tests?

The most common impact tests are either Charpy or Izod. Charpy tests are implemented according to ISO 179-1 and ASTM D6110. Instrumented Charpy tests to ISO 179-2. Izod tests are performed according to ISO 180, ASTM D256, ASTM D4508 and "unnotched cantilever beam impact" to ASTM D4812.

Impact bending test to Charpy

Charpy to ISO 179-1 is the preferred test method on plastics within the standard for single-point data ISO 10350-1. The test is ideally performed on unnotched specimens with edgewise impact (1eU). Should the specimen not break during the test, any subsequent tests are performed with notched specimens. In this case, a comparison of the test results is not possible. If the notched specimen still does not break, the impact tensile method is used.

Instrumented Charpy impact bending test

By plotting the force time sequence, a force time diagram with excellent accuracy can be achieved through double integration using high-quality measurement technology. The resulting data can be used in different ways:

  • Additional characteristic values that enhance the understanding of material behavior
  • Fracture mechanical characteristic values
  • Automatic, operator-independent determination of the type of break using the curve progression in the force travel diagram

For one, the measured value curves always display characteristic oscillations. These oscillations originate from the specimen, whose frequency is in a defined functional relationship with the specimen geometry, the dimensions and the modulus value of the polymer. The wide measurement range is another major advantage of the instrumentation. These instruments measure forces and not energies, as is the case with conventional pendulum impact testers. Since the measurement electronics allow for precise measurements as low as 1/100 of the nominal force, the lower end of the measurable impact energy is usually determined by the duration of the test and by the natural frequency of the measuring elements. This makes it possible to cover the entire measurement range described in ISO 179-2 with two instrumented pendulum hammers.

Impact bending test to Izod

In the American ASTM standard, testing is mainly performed according to the Izod test method, which is described in ASTM D256. Within this standard all impact tests are performed using notched specimens. If only small specimens can be produced, the chip impact method to ASTM D4508 can be used. It is a counterpart to the Dynstat impact test.

Products for impact testing with pendulum impact testers

Impact Tests with Drop Weight Testers

Drop weight test
to Drop weight test
Drop weight test on metals
DIN EN 10274, API 5L
to Drop weight test on metals
Puncture test on plastics
ISO 6603-2, ISO 7765-2, ASTM D3763
to Puncture test on plastics

Products for impact testing with drop weight testers

Impact Tests with High-Speed Testing Machines

The HTM high-speed testing machine is of universal use in plastics testing. It covers a very high test speed and large force range, and can be used in both tensile and compression tests with a great level of flexibility. The performance of tests in a wide range of temperatures is made possible through the use of temperature chambers.

Puncture test on plastics
ISO 6603-2, ISO 7765-2, ASTM D3763
to Puncture test on plastics

Products for impact testing with high-speed testing machines

Top