ASTM E606 Strain-Controlled Fatigue Test

ASTM E606 Strain-Controlled Fatigue Test Scope:

The standard test method for Strain-Controlled Fatigue Test by ASTM E606 determines fatigue properties of nominally homogeneous materials. The test is mainly performed in support of activities like materials research and development, mechanical design, process and quality control, product performance, and failure analysis. Strain-controlled fatigue can also be an important consideration in the design of industrial products. ASTM E606 test is intended primarily for strain controlled fatigue testing but some sections may provide useful information for force-controlled or stress-controlled testing.

Test Procedure:

For ASTM E606, the sample is loaded into a fatigue tester or fatigue test machine and loadedusing the predetermined test stress, then unloaded to either zero load or an opposite load. This cycle of loading and unloading is then repeated until the end of the test is reached. The test may be run for a predetermined number of cycles or until the sample has failed depending on the parameters of the test.

When the magnitudes of the time-dependent and time-independent inelastic strains are on the same order or lower, the ASTM E606 test technique can be used at those temperatures and strain rates. Environmental elements, such as temperature, pressure, humidity, medium, and others, are not restricted as long as they are controlled throughout the test, do not result in dimensional loss or change over time, and are specified in the data report.

The characteristics of strain-controlled fatigue place certain demands on fatigue testing techniques. In particular, cyclic total strain should be calculated, as well as cyclic plastic strain. Additionally, either of these strains is frequently employed to set cyclic boundaries; total strain is normally managed throughout the cycle. The ability to calculate cycle stresses and strains at any point during the testing is what makes this test method special and produces the results it does.

Designing industrial items necessitate taking strain-controlled fatigue into account. It is crucial in instances when parts or pieces of parts experience cyclic plastic strains that are either mechanically or thermally produced and lead to breakdown after just a few (about 105) cycles. Establishing design guidelines to prevent component failure by fatigue may benefit greatly from the information acquired from this strain-controlled fatigue testing.

Video 01: ASTM E606 Strain-Controlled Fatigue Test

Specimen Size:

According to ASTM E606, it is desirable to obtain test specimens from sheet materials less than 6.0 mm (0.24 inch) thick.

For the duration of the test, the controlled temperature of the specimen should be Tn ± 2°C.

Data:

In ASTM E606, strain controlled fatigue is reported in SI units or inch pounds and is considered as a standard separately.

For materials that are fatigue tested at temperatures other than ambient, all temperatures shall be Tn ± ∆T.

Where,

Tn = nominal test temperature in °C.

∆T= 2°C or 1% ×Tn °C whichever is greater.

Conclusion:

ASTM E606 is a standard test method that covers testing procedures to measure the fatigue properties of nominally homogeneous materials by subjection to uniaxial forces.