Issue 43

P. Zampieri et alii, Frattura ed Integrità Strutturale, 43 (2018) 90-96; DOI: 10.3221/IGF-ESIS.43.06 90 Fatigue strength of corroded bolted connection Paolo Zampieri, Andrea Curtarello, Carlo Pellegrino Department of Civil, Environmental and Architectural Engineering, University of Padova, Via Marzolo, 9 - 35131 Padova, Italy paolo.zampieri@dicea.unipd.it , http://orcid.org/0000-0002-4556-5043 Emanuele Maiorana OMBA Impianti & Engineering SpA, Via della Croce 10, 36040 Torri di Quartesolo (VI), Italy A BSTRACT . This note summarizes some recent investigation results on the behavior of corroded steel bolted joints under uniaxial fatigue loading. Fatigue test specimens, were made up using S355 structural steel plates joined together with preloaded M12 bolts of class 10.9 with a geometry that corresponds to the Δσ = 112 MPa EC3 detail category. The accelerated corrosion process was accomplished using an electrolyte consisting of an aqueous 5% NaCl solution whereby the specimens were treated. In particular, during the corrosion process specimens were repeatedly immersed for 2 minutes in the electrolyte and then removed keeping them 60 minutes long in free air at 35 °C. An atmospheric corrosion in marine-industrial environment is well- represented through corrosion test. Fatigue loading tests and surface morphology measurement of uncorroded and corroded specimens were performed and the results were compared. K EYWORDS . Fatigue strength; Corrosion; Bolted connections; Steel bridge. Citation: Zampieri, P., Curtarello, A., Pellegrino, C., Maiorana, E., Fatigue strenght of corroded bolted connection, Frattura ed Integrità Strutturale, 43 (2018) 90-96. Received: 08.08.2017 Accepted: 30.10.2017 Published: 01.01.2018 Copyright: © 2018 This is an open access article under the terms of the CC-BY 4.0, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. I NTRODUCTION n civil engineering, the structures most affected by mechanical fatigue are steel railway bridges that are subjected to a large number of traffic load cycles during their service life. In this type of structures, the most critical elements from the point of view of fatigue strength are the connections between the members; the irregularity of the connections geometry is one of the factors that affect the fatigue life of these structural elements. The fatigue life assessment of structural details is widely studied in the recent years [1, 2]. Another important factor of great influence on the fatigue strength of bridge structure is the material degradation [3-5]. In particular, corrosion phenomenon is perhaps one of the problems that most affects the integrity of metal structures in all countries. In this context, understanding the corrosion effects on the fatigue life of steel structures is becoming a topic on which research is investing. Many studies were conducted on the corrosion and fatigue phenomena, however there are few publications regarding their interaction in steel bridges. Researches are carried out in fields different than the civil sector, e.g. structures working in the I