Fretting fatigue in steel stay cables

摘要

The present work deals with the so-called free bending fatigue problem of stay dables. Experimental findings about the ocurrence of the fatigue failure initiation in a two layer spiral strand are first presented. A theoretical model of the mechanical behaviour of a two layer spiral strand undergoing a steady axial tension and lateral oscilations which induce bending deformations close to the restrained ends is briefly introduced. The initiation of fretting fatigue cracks is discussed through the identification of the loading conditons at the interlayer contact patches. The relevant fretting fatigue parameters are deduced from the model in order to reporduce the actual loading conditions in fretting fatigue tests.