A method for the strain rate dependent correction for control type of fatigue tests

In this paper, we investigate the influence of the control type of cyclic tests on the lifetime of the specimens tested. We present a strain rate dependent method to compare results of displacement controlled fatigue tests to results of force controlled fatigue tests. This method is successfully used to explain longer lifetimes observed in ultrasonic fatigue tests compared to conventional fatigue tests on specimens manufactured from quenched and tempered SAE 4150. This method may also be used to normalize displacement controlled fatigue tests in conventional testing, which allows parallel testing of multiple specimens in a single testing machine.