PSI - Issue 75

Florian Kalkowsky et al. / Procedia Structural Integrity 75 (2025) 581–592 Florian Kalkowsky et al. / Structural Integrity Procedia 00 (2019) 000 – 000

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5. Conclusion and Outlook The experimental studies have provided important insights into the fatigue behavior of components in bearing type connections. No significant differences between the fatigue resistance of bearing type connections with bolts or blind rivets could be observed. The geometric parameters of the connections as well as the tensile strength of the component material influenced the value of the fatigue strength much more. Based on the numerical simulations to determine the stress concentration factor as input parameter, a linear dependency of this related geometric parameters ( 1 , 1 , 2 , 2 ) was identified. By systematically variation of this parameters, diagrams for a pure analytical fatigue strength verification were derived. By the comparison of the DC’s from fatigue tests and subsequent statistical evaluation with the fatigue resistance acc. to the FKM approach (based on effective notch stress concept for non-welded constructional details), a sufficient alignment could be observed. This led the authors to derive an expression for the DC according to the calculation method of the FKM-Guideline. From now on, the expression for the DC considers both the tensile strength and the notch effect directly in the verification with a fully new approach. Several conservative assumptions have been made in deriving the design proposal. This conservatism should be eliminated by further investigations. The investigations should also take into account the typical steel structure manufacturing practice. For example, the design proposal is currently limited to the hole manufacturing by drilling. Other cutting methods such as laser, plasma, flame cutting are common in this application field. Corrosion protection. systems such as hot-dip galvanizing are also frequently used, which also influence the fatigue behavior, see Kalkowsky et al. (2025). It would also be desirable to have a guideline for determining secondary bending effects in the connection. In the ongoing publicly funded project Flügge et al. (2023), the authors are also addressing these issues for other non-welded constructional details, see Glienke et al. (2024a, 2024b); Schröder et al. (2025a); Schröder et al. (2025b); Aljomaa et al. (2025). Acknowledgements The IGF-project (Nr. 20037BR) of the European Research Association for Sheet Metal Working e.V. (EFB), 30559 Hannover and IGF-project (Nr. 01IF22108N) from the Research Association for Steel Application (FOSTA), Düsseldorf have been funded by the DLR and AiF within the program for sponsorship by Industrial Collective Research (IGF) of the German Federal Ministry of Economic Affairs and Climate Action based of a decision by the German Bundestag. In addition, the authors would like to thank all project partners involved. References Aljomaa, M.; Stranghöner, N.; Schröder, M.; Glienke, R.; Schwerdt, D.; Kalkowsky, F.; Flügge, W. (Hg.) (2025): Influence of Various Cutting Methods on the Fatigue Strength of Slip-Resistant Connections in Steel Structures. IABSE Congress Ghent 2025. Ghent, August, 27-29,2025. Allan, R. N.; Fisher, J. W. (1967): Behavior of bolted joints with oversize or slotted holes. Hg. v. Lehigh University. Civil and Environmental Engineering. Pennsylvania (USA) (Fritz Laboratory Reports, 318.3). Brown, J. D. (2006): Punched Holes in Structural Connections. The University of Texas at Austin. Austin. Díaz, J. I. (1971): A critical survey on riveted joints and an analysis of the frictional resistance of riveted joints with eccentric load. University of Houston. Houston. ECCS (2018): Background information on fatigue design rules. Statistical evaluation. 2nd edition. Brussels (European Convention for Constructional Steelwork). EN 1993-1-8, 2010: Eurocode 3: Design of steel structures - Part 1-8: Design of joints. Albrecht, P.; Sahil, A. H.; Wattar, F. (1987): Fatigue strength of bolted joints. In: Journal of Structural Engineering (119), S. 1834 – 1849. DOI: 10.1061/(ASCE)0733-9445(1987)113:8(1834.

EN 1993-1-9, 2010: Eurocode 3: Design of steel structures – Part 1-9: Fatigue. FprEN 1993-1-9, 2024: Eurocode 3: Design of steel structures – Part 1-9: Fatigue. EN 1990, 2021: Eurocode: Basis of structural design.