Issue 43

E. Maiorana et alii, Frattura ed Integrità Strutturale, 43 (2018) 205-217; DOI: 10.3221/IGF-ESIS.43.16 205 Experimental tests on slip factor in friction joints: comparison between European and American Standards Emanuele Maiorana OMBA Impianti & Engineering SpA, Via della Croce, 10 - 36040 Torri di Quartesolo (VI), Italy emaior@libero.it , http://orcid.org /0000-0002-3574-1410 Paolo Zampieri, 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 A BSTRACT . Friction joints are used in steel structures submitted to cyclic loading such as, for example, in steel and composite bridges, in overhead cranes, and in equipment subjected to fatigue. Slip-critical steel joints with preloaded bolts are characterized by high rigidity and good performance against fatigue and vibrational phenomena. The most important parameter for the calculation of the bolt number in a friction connection is the slip factor, depending on the treatment of the plane surfaces inside the joint package. The paper focuses on the slip factor values reported in European and North American Specifications, and in literature references. The differences in experimental methods of slip test and evaluation of them for the mentioned standards are discussed. The results from laboratory tests regarding the assessment of the slip factor related to only sandblasted and sandblasted and coated surfaces are reported. Experimental data are compared with other results from the literature review to find the most influent parameters that control the slip factor in friction joint and differences between the slip tests procedures. K EYWORDS . Bolted joints; Slip resistance; k -factor; Slip factor; Surface treatment. Citation: Maiorana, E., Zampieri, P., Pellegrino, C., Experimental tests on slip factor in friction joints: comparison between European and American Standards, Frattura ed Integrità Strutturale, 43 (2018) 205-217. Received: 01.12.2017 Accepted: 10.12.2017 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 urocode EN 1993-1-8 [1] provides the main recommendations of methods for the effective design of joints using steel grades S235, S275, S355 and S460 and prescribes that only bolt assemblies of classes 8.8 and 10.9, conforming to the requirements of high strength structural bolting for preloading with controlled tightening E