Fatigue testing
In materials science, fatigue generally indicates the weakening of a material caused by cyclic loading, which leads to structural damage.
Materials can be damaged by repeated loading, resulting in a gradual loss of strength to the point of total failure.
Fatigue testing helps to determine the expected service life of a material subjected to cyclic loading. It is also used to study materials’ resistance to damage, the loss of mechanical properties and failure under repeated loading. Furthermore, it can be used to establish criteria for accepting or rejecting components made of polymeric and/or composite materials.
How is a fatigue testing performed?
Fatigue testing involves producing cyclic loading and unloading in tension, compression, bending, torsion and in different combinations. The results of fatigue testing are generally presented as diagrams of cyclic stress, known as S-N curves or Wöhler curves, which indicate the number of cycles the sample can withstand before breakage, given the range of cyclic stress applied. These curves show the number of cycles before sample failure and the amplitude of the cyclic stress applied.
Fatigue testing is therefore used to calculate a material’s characteristic properties, as well as its fatigue life. It can also be used to evaluate the effect of environmental factors such as temperature, humidity and loading speed on fatigue of the material.
AIMPLAS has fatigue testing equipment with a load capacity of up to 100 kN and working speeds of up to 100 Hz (depending on the required amplitude). Our equipment can apply tensile, compressive and bending stress to both test specimens and final parts. We can also use a temperature chamber to perform tests carried out at working temperatures of -70 to 250°C.
This equipment can be used to apply standards such as ISO 13003 and ASTM D3479, which are valid for fatigue testing on composites and other materials. Contact us for more information.
