PSI - Issue 38

ScienceDirect ScienceDirect Structural Integrity Procedia 00 (2021) 000 – 000 Available online at www.sciencedirect.com ScienceDirect Structural Integrity Procedia 00 (2021) 000 – 000 Available online at www.sciencedirect.com Available online at w.sciencedirect.com Procedia Structural Integrity 38 (2022) 401–410

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2452-3216 © 2021 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 scientific committee of the Fatigue Design 2021 Organizers 10.1016/j.prostr.2022.03.041 2452-3216 © 2021 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 scientific committee of the Fatigue Design 2021 Organizers 2452-3216 © 2021 The Authors. Published by ELSEVIER B.V. This is an open acc ss article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of t e scientific committee of the Fatigue Design 2021 Organizers © 2021 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 scientific committee of the Fatigue Design 2021 Organizers Abstract In this paper, experimental and numerical studies are performed to quantify the influence of overloads on the fatigue behaviour of the quenched and tempered steel 42CrMoS4 and the wrought aluminium alloy EN AW-6082 T6. The main objective is to incorporate the influence of overloads in the fatigue assessment. Three series of fatigue tests per material were performed, each under load control conditions, at = −1 : i) constant amplitude loading (CAL) tests with no overloads; ii) CAL tests after five overload cycles of the magnitude OL 1; iii) CAL tests after five overload cycles of the magnitude OL 2. The respective overload levels are selected to achieve 75 % of the static strength of the test samples either estimated according to the FKM Guideline (2020) for OL 1 or determined directly by specimen testing for OL 2. During the overload cycles, the local notch strains were monitored by means of the digital image correlation (DIC) technique. X-ray diffraction was applied to quantify the residual stresses in the specimens due to manufacturing, after applying overload cycles, as well as after completing tests on runouts. Fatigue test results demonstrate that, depending on the material and the overload level, the fatigue strength can either decrease or increase or, in some cases, be only slightly affected by overloads. To explain the experimental findings, residual stresses determined from both experimental measurements and elastic-plastic finite-element analyses are included in the calculations of the notch stresses and strains and a fatigue damage parameter. The latter is then involved in the damage calculations to quantify the effect of overloads in terms of the magnitude and number of cycles to failure. Keywords: Overloads (OL); S-N curves; fatigue strength; digital image correlation; finite-element analyses; residual stress 1. Introduction Overloads can occur as rare events during machine operation, such as abnormal service conditions, malfunctions, operating errors or mishandling. Under certain conditions, single overloads may cause considerable material damage and reduce the fatigue life of a component. For the strength assessment of metallic components, FKM (Forschungskuratorium Maschinenbau, respectively Research Association of Mechanical Engineering) has published Abstract In this paper, experimental and numerical studies are performed to quantify the influence of overloads on the fatigue behaviour of the quenched and tempered steel 42CrMoS4 and the wrought aluminium alloy EN AW-6082 T6. The main objective is to incorporate the influence of overloads in the fatigue assessment. Three series of fatigue tests per material were performed, each under load control conditions, at = −1 : i) constant amplitude loading (CAL) tests with no overloads; ii) CAL tests after five overload cycl s of the m gnitude OL 1; iii) CAL tests afte five verload cycles of the magnitude OL 2. The respective o erload levels are selecte to achi ve 75 % of the static streng of the tes s mples either estimated according to the FKM Guid line (2020) for OL 1 or determin d directly by specimen testing for OL 2. During the overl ad cycl s, the local notch strains were onitored by means of the digital mage correlation (DIC) technique. X-ray diffraction was applied to quantify the residual stresses in th sp cimens du t manuf cturing, after applying overlo d cycles, as well as aft r completing tests on runouts. Fatigue test results demonstrat that, depending on the mat rial and the overload l vel, the fatigue strength can either decreas or increase or, in some cases, be only slightly aff ted by overloads. To explain the experimental fin ings, residual stresses determin d fr m both experimental measurements and elastic-plastic finite-element analyses re i cluded in the calcula ons of the notch stres es and trains a d a fa igue damage parameter. The latter is then involved in the damage calculations to quantify the effect of ove load in term of the magnitu e and umber of cycles o failu e. Keywords: Overloads (OL); S-N curves; fatigue strength; digital image correlation; finite-element analyses; residual stress 1. Introduction Overloads can occur as rare events during machine operation, such as abnormal service conditions, malfunctions, operating errors or mishandling. Under certain conditions, single overloads may cause considerable material damage and reduce the fatigue life of a component. For the strength assessment of metallic components, FKM (Forschungskuratorium Maschinenbau, respectively Research Association of Mechanical Engineering) has published FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design On the evaluation of overload effects on the fatigue strength of metallic materials Kimiya Hemmesi a , Franz Ellmer b , Majid Farajian c , Igor Varfolomeev a , Michael Luke a FATIGUE DESIGN 2021, 9th Edition of the International Conference on Fatigue Design On the evaluation of overload effects on the fatigue strength of metallic materials Kimiya Hemmesi a , Franz Ellmer b , Maji Farajian c , Igor Varfolomeev a , Michael Luke a a Fraunhofer Institute for Mechanics of M terials IWM, Freiburg, Germany b SWM Struktur- und Werkstoffmechanikforschung, Dresden, Germany c GSI Gesellschaft für Schweißtechnik International, Duisburg, Germany a Fraunhofer Institute for Mechanics of Materials IWM, Freiburg, Germany b SWM Struktur- und Werkstoffmechanikforschung, Dresden, Germany c GSI Gesellschaft für Schweißtechnik International, Duisburg, Germany