What is Torsion Testing

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A torsion test is used to determine how a material or part performs under twisting force. It is a common test within mechanical engineering, and used for items like fasteners, beams, axles etc.

Torsion Test Categories

Torsion testing can be split of in a few different types.

  • Test for Failure: In this test a sample is twisted until failure, and is used to determine the strength of the sample.
  • Proof Test: This test is used to validate that a sample can withstand a given torque ove a set period of time.
  • Operational Testing: This test measures the samples performance under expected condition during normal use by the costumer.

Why use Torsion Testing

There can be several reasons to perform torsion testing during development of a product. For example the axles turning the wheels on a vehicle, if they started to get plastic deformation during acceleration, they would not last long.
In similar way, then it could have critical consequences if the axle turning the knife on a lawnmower broke due to not being designed to withstand the torsion applied to it.

Torsion Test Setup

The sample is typically fixed in one end, and then a torsional force is added in the other end. The stress and strain is recorded and displayed in a stress-strain diagram. The twist angle is on the x axis and the toque value is display on the y axis.

From the diagram following can be determined.

  • Max Toque Strength
  • Angular displacement at a given load
  • Stiffness (From the linear part of the curve before plastic deformation take place)
  • Yield Toque

If you would like to know more about torsion testing and how to use it as part of problem solving or risk mitigation, then our 8D Training or FMEA Training might be of interest to you.

Alternatively you can continue to our quality training page to see our available courses.

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Torsion Testing