Issue 41

S.M.J. Razavi et alii, Frattura ed Integrità Strutturale, 41 (2017) 432-439; DOI: 10.3221/IGF-ESIS.41.54 432 Effect of hot dip galvanization on the fatigue strength of steel bolted connections S.M.J. Razavi, M. Peron, J. Torgersen, F. Berto, F. Mutignani Department of Mechanical and Industrial Engineering, Norwegian University of Science and Technology (NTNU), Norway javad.razavi@ntnu.no , mirco.peron@ntnu.no , jan.torgersen@ntnu.no , filippo.berto@ntnu.no A BSTRACT . Hot dip galvanized steel bolted joints has been tested under fatigue loading to evaluate the effect of galvanizing coating on the fatigue strength of S355 structural steel. The experimental results showed that the decrease of the fatigue life of coated specimens in comparison with that of uncoated joints is very limited and the results are in good agreement with Eurocode detail category, without substantial reductions. The procedure for coating and preparation of the bolted joints is described in detail in this paper providing a useful tool for engineers involved in similar practical applications. The experimental results are compared with the previously published data on central hole notched galvanized and not treated specimens characterized by the same geometry. K EYWORDS . High cycle fatigue; Galvanized steel; Notch effect; Bolted joints. Citation: Razavi, S.M.J., Peron, M., Torgersen, J., Berto, F., Mutignani, F., Effect of hot dip galvanization on the fatigue strength of steel bolted connections, Frattura ed Integrità Strutturale, 41 (2017) 432-439. Received: 15.05.2017 Accepted: 24.05.2017 Published: 01.07.2017 Copyright: © 2017 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 ajority of mechanical structures are made of various components which are connected using various kinds of joining methods such as welding, bolting, riveting and bonding. However, according to specific geometry of these joints, they are mostly considered as the critical components in structures. [1-6]. Due to their versatility and reliability, bolted connections are one of the most widely used methods for joining structural steel members. Among the numerous advantages of bolting as a joining method compared to the other methods of joining the following can be summarised: affordable process with less required time and cost, ease of assembly and inspection, reliability of service and good performance under variable applied loads [7]. The durability of structural components is significantly influenced by the environmental factors such as degree of corrosion encountered in service operative conditions [8-11]. Deterioration due to corrosion usually leads to the seizure of fasteners and premature failures, in the form of corrosion fatigue. Therefore, proper protections of the bolted joints from corrosion should be considered as the key parameter in design of the components. As a surface treatment, hot dip galvanizing protect the core material from corrosion and environmental aggressive agents and can be used in a wide range of materials and applications [12-17]. As the surface condition may directly effects the fatigue initiation of the materials, some authors correlated the fatigue strength to the coating thickness of the zinc layer [18]. On the other hand, other authors did not support any specific M