https://popups.uliege.be/esaform21/index.php?id=4758 Index terms fr 0 https://popups.uliege.be/esaform21/index.php?id=3869 The integration of forming in the fatigue modelling of cold-formed components significantly improves the predictive accuracy of the estimated life. The current study investigated the fatigue behaviour of a bent specimen made from a 5 mm thick, S900MC high strength steel plate. Because of its superior static and dynamic strength, this grade is progressively used for hollow cold-formed sections in mobile applications. However, it exhibits a strong stress saturation as well as limited formability. In this regard, a finite element modelling framework was adopted from previous research and further developed to integrate bending in the fatigue modelling and life estimation procedure. However, this framework currently ignores the possible influence of kinematic hardening and associated Bauschinger effect. For this reason, a numerical study was performed that compares isotropic with kinematic hardening for this specific application. First, the characteristic behaviour of these models was verified in a virtual tension-compression test. Subsequently, they were implemented in forming simulation followed by fatigue loading. Herein, the stress-strain evolution was investigated and a multi-axial fatigue criteria was used to map the sensitivity of the estimated life to the type of hardening. In general, the stress that entered the fatigue calculation was at least 21% lower for the kinematic model. As a result, a significant increase of 65% was observed for the estimated fatigue life, yielding a better comparison with experimental data. Mon, 29 Mar 2021 14:52:43 +0200 Thu, 08 Apr 2021 21:11:43 +0200 https://popups.uliege.be/esaform21/index.php?id=3869 https://popups.uliege.be/esaform21/index.php?id=3826 Steel fibers as concrete reinforcement improve the building material’s mechanical properties and enlarges its field of application. The production of steel fibers by the process chain notch rolling and cyclic bending promises energetic improvement compared to the conventional manufacturing process wire drawing. The innovative procedure is not yet researched extensively and modelling of the material behavior brings with it many challenges. Different stress states of both process steps require various material models and material failure must be considered. The study brings an appropriate modelling of the test sheet metal DP600 with a thickness of t0=0.8 mm for the second process step into focus. The wire strip’s notches are exposed to a cyclic tension-compression load for which high strength steel exhibits early yielding and a distinct transient region of the stress-strain curve after load reversal. For this reason, the isotropic-kinematic hardening model by Chaboche and Rousselier determined in tension-compression tests is validated by cyclic bending tests. For considering crack initiation, an appropriate ductile damage model for depicting material fatigue is identified. To allow practical realization of the process and validation of the material model, an experimental test method for manufacturing wire strip samples by notch stamping is introduced. Mon, 29 Mar 2021 14:45:38 +0200 Thu, 08 Apr 2021 20:53:00 +0200 https://popups.uliege.be/esaform21/index.php?id=3826