Fatigue is the progressive, localized, permanent structural change that occurs in materials subjected to fluctuating stresses and strains that may result in cracks or fracture after a sufficient number of fluctuations. Fatigue fractures are caused by the simultaneous action of cyclic stress, tensile stress and plastic strain. If any one of these three is not present, fatigue cracking will not initiate and propagate. The cyclic stress starts the crack; the tensile stress produces crack growth (propagation). Although compressive stress will not cause fatigue, compression load may do so. Fatigue failure occurs at stress levels below the ultimate tensile strength of the material.
Fatigue testing carried out at AEIS can be done both at high loads and high frequencies. We are able to carry out both High Cycle Fatigue testing and Low Cycle Fatigue Testing.
Fatigue testing will be carried out on machines with servo-hydraulic systems. Some of the standards utilized at AEIS for Fatigue testing are mentioned below:
| Astm Testing Capabilities |
| A 370 |
Standard for Test Methods and Definitions for Mechanical Testing of Steel Products |
|
| E-466 |
Standard Practice For Conducting Force Controlled Constant Amplitude Axial Fatigue Tests of Metallic Materials |
|
| E-606 |
Standard Practice For Strain-Controlled Fatigue Testing |
|
| E- 647 |
Standard Test Method for Measurement of Fatigue Crack Growth Rates |
|
| E-2207 |
Standard Practice for Strain-Controlled Axial-Torsional Fatigue |
