Contribution to the study of the influence of the stress ratio on the high cycle fatigue behaviour of riveted joints

Abstract

Old riveted railway bridges are part of the cultural and technological heritage in many countries. The assessment of the actual behaviour and the remaining life of these structures is a key economical factor in the management of these bridges. This evaluation should take into account the evolution of the traffic loads, which have constantly increased since their construction, and a realistic estimation of the fatigue life derived from representative experimental tests. This study deals with the fatigue behaviour of riveted assemblies with specimens prepared from materials sampled in two old bridges: a railway bridge over the Adour river (France) built in 1862-1864 and the Stahringer bridge (Germany), constructed in 1895. Because all assemblies are not subjected to the same loads, this research concentrates on the influence of the stress ratio R on the fatigue behaviour. In order to quantify this influence, a comparison between the Basquin linear model and the Weibull model is performed. It is shown that a formula proposed in a recent study to determine the fatigue strength for an arbitrary value of R is not suitable in the high-cycle fatigue regime.

Virtual special issue: Advances in structural integrity research

“…5 The effect of the stress ratio R is studied for high cycle fatigue loading of old bridges riveted structures using different models. 6 Distortion-induced fatigue cracking is a concern for many aging steel bridges. An experimental study, supported by digital image correlation (DIC), in which a half-scale steel girder to cross frame subassembly was subjected to distortion-induced fatigue loading to produce multiple geometrically complex cracks, is presented.…”

“…The effect of the stress ratio R is studied for high cycle fatigue loading of old bridges riveted structures using different models 6 . Distortion‐induced fatigue cracking is a concern for many aging steel bridges.…”