PSI - Issue 28

ScienceDirect Structural Integrity Procedia 00 (2019) 000–000 Structural Integrity Procedia 00 (2019) 000–000 Available online at www.sciencedirect.com Available online at www.sciencedirect.com ScienceD rect Available online at www.sciencedirect.com ScienceDirect

www.elsevier.com/locate/procedia www.elsevier.com/locate/procedia

Procedia Structural Integrity 28 (2020) 2335–2341

© 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Abstract In order to reduce the energy demand and harmful emissions of moving masses, lightweight construction is becoming increasingly important. In many areas of product manufacturing the constructions consist of individual components and sheets that are joined together to form complex structures. Due to the simplicity of the process, clinching without auxiliary joining parts or pre-holes is often used. The utilized sheets are usually less than 2 mm thick and possibly characterized by anisotropy in the mechanical material properties because of different rolling directions. The sheets are arranged in an overlapping and partially interspersed way, so that impact extrusion results in an inseparable connection between the components made of the same or even different materials. During the joining process and due to the service load, cracks can occur in the area of the joint, propagate due to cyclic loading and consequently lead to structural failure. Within the scope of this paper experimental and numerical preliminary tests for the fracture mechanical characterization of the metal sheets used in the clinching process as well as first crack growth rate curves are presented. In order to determine the fracture mechanical parameters of the base material, the development of a new specimen geometry is necessary due to the low sheet thickness. The numerical calculation of the geometry factor function as well as the calibration function of this special specimen geometry enables the determination of the crack growth rate curves. Following the experimental validation of the numerically determined calibration function, crack growth rate curves are determined for the stress ratio R = 0.1. Furthermore, different rolling directions and further R -ratios are considered in the experimental investigations to examine the influence of the anisotropy arising during rolling and the mean stress sensitivity. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo Keywords: clinching; fatigue crack growth; metal sheet; special specimen geometry; crack growth rate curve 1st Virtual European Conference on Fracture Development of a special specimen geometry for the experimental determination of fracture mechanical parameters of clinchable metal sheets D. Weiß*, B. Schramm, G. Kullmer Applied Mechanics (FAM), Paderborn University, Pohlweg 47-49, 33098 Paderborn, Germany Abstract In order to reduce the energy demand and harmful emissions of moving masses, lightweight construction is becoming increasingly important. In many ar as of product manuf cturing the constructions consist of individual components and sheets that are joined together to for complex structures. Due to the simplicity of the process, clinchi g without auxiliary joining part or pre-holes is often used. The utilized sheets are usually less than 2 mm thick and possibly characterized by nisotropy in the mechanical mat rial properti s because of iffer nt rolling directions. The sheets are arranged in an overlapping and partially intersp rsed w y, so th t impact extrusion results in an inseparable connection between the compone ts mad of the same or even different materials. During the joining pr cess and due to the service load, cracks can occur in the area of the joint, propagate ue to cyclic loading a d consequently lead to structural failure. Within the scope of this paper exp rimental and numerical preliminary tests for the fracture mechanical characterization of the m tal sheets used in the clinching proc ss as well as first cra k growth rate curves are presented. In order to determine the fractur chanical parameters of the base material, the development of a new specimen geometry is necessary du to the low sheet thickness. The nu erical calculation of the geometry factor function as well as the calibration function of this special specimen geom try enables the determination of the crack growth rate c rves. Follo ing the experimental validation of the numerically d termined calibration function, cr ck growth rate curves are d termined for the stress ratio R = 0.1. Furthermore, different rolling directions and further R -ratios are considered in the experimental investigations to examine the influence of the anisotropy arising duri g rolling and the mean stress sensitivity. © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of European Structural Integri y Soci ty (ESIS) ExC Keywords: clinching; fatigue crack growth; metal sheet; special specimen geometry; crack growth rate curve 1st Virtual European Conference on Fracture Development of a special specimen geometry for the experimental determination of fracture mechanical parameters of clinchable metal sheets D. Weiß*, B. Schramm, G. Kullmer Applied Mechanics (FAM), Paderborn University, Pohlweg 47-49, 33098 Paderborn, Germany

* Corresponding author. Tel.: +49-5251-60-4389; fax: +49-5251-60-5322. E-mail address: weiss@fam.upb.de * Corresponding author. Tel.: +49-5251-60-4389; fax: +49-5251-60-5322. E-mail address: weiss@fam.upb.de

2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 2452-3216 © 2020 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo

2452-3216 © 2020 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of the European Structural Integrity Society (ESIS) ExCo 10.1016/j.prostr.2020.11.081