Author(s)

C. Makabe, S. Nishida, C. Urashima & H. Kaneshiro

Abstract

A method of detecting fatigue crack initiation in some weak section of a machine element is examined using a holed specimen under random load conditions. Waveforms of two strain functions, that is hl=E ,^+XE ^ and h2=s ,-A.E ^ are successively observed, e^and E are the strains in the vicinity of the hole and X, is the strain range ratio Ac ,^/Ae ^ The function hi can be used to substitute for the load parameter and the waveform of h2 changes its shape after the crack initiation due to the crack closure behavior. Therefore, we can detect the fatigue crack initiation at the hole by comparison of these two

Keywords