Benjamin Guennec

Reconfirmation and new discussions on frequency effect of fatigue property of materials based on numerous published data

Ultrasonic fatigue testing is a convenient method to examine the S-N property in long life region, within a definite period. However, a distinct gap of the loading stressing frequency between conventional and ultrasonic testing methods (100–1,000 times larger) urges us to study a potential effect of the loading frequency. The present paper deals with a comparison of results obtained from conventional and ultrasonic tests, in the high cycle fatigue region, from two viewpoints. Firstly, a short direct comparison of fatigue data from conventional and ultrasonic tests, with similar conditions, has been undertaken. Secondly, overview analyses based on a far larger amount of data have been carried out for structural steels and aluminium alloys. Results obtained from this work give us some idea of the extent of differences between fatigue test results obtained at usual and ultrasonic frequencies in the fatigue regime of N f < 10 7 cycles. Particularly, the second study gives a potential 18% difference of fatigue strength for steels, whereas it reveals only a slight difference of fatigue behaviours for aluminium alloys.