Low Cycle Fatigue Experiments With Variation of the Strain Range

Synopsis

In comparison to the constant strain range experienced in the standard LCF-test, material in service undergoes complex loading patterns. These changes in load can be expressed as a sequence of strain cycles with different strain ranges.

The strain cycles arising during operation usually are sorted into groups of equal strain range and are combined to predict lifetime using the “linear life fraction rule”. This method is practical but suffers from the defect that it has no physical basis and does not take the sequence of cycles at different strain range into account. An experimental programme has been thus carried out to confirm the applicability of this rule to nuclear components.