Effects of loading frequency on fatigue behavior of metallic materials-A literature review

The topic of loading frequency effect on fatigue behavior is in close relation to high-cycle fatigue (HCF) and very-HCF (VHCF) research. The conventional loading frequency in fatigue tests is normally between 10 and 100 Hz. In order to accelerate testing process, researchers have developed ultrasonic vibration device with a very high frequency, for example, 20 kHz, to perform VHCF tests. Thus, a question has always been asked: Does loading frequency affect the fatigue behavior of tested material? It is obvious that the answer is yes because the remarkable difference in strain rate with respect to different loading frequencies may cause the change of fatigue mechanism and the related fatigue performance. The subsequent question is how is the effect of loading frequency on fatigue behavior? This paper attempts to address such questions by two cases of experimental investigations. Moreover, typical results in literature are quoted for the further discussion of this issue