Issue 38

M. Springer et alii, Frattura ed Integrità Strutturale, 38 (2016) 155-161; DOI: 10.3221/IGF-ESIS.38.21 155 Focussed on Multiaxial Fatigue and Fracture Combined simulation of fatigue crack nucleation and propagation based on a damage indicator M. Springer Vienna University of Technology, Institute for Lightweight Design and Structural Biomechanics, Austria springer@ilsb.tuwien.ac.at M. Nelhiebel KAI – Kompetenzzentrum Automobil- u. Industrieelektronik GmbH, Austria Infineon Technologies Austria AG, Austria Michael.Nelhiebel@infineon.com H. E. Pettermann Vienna University of Technology, Institute for Lightweight Design and Structural Biomechanics, Austria pettermann@ilsb.tuwien.ac.at A BSTRACT . Fatigue considerations often distinguish between fatigue crack nucleation and fatigue crack propagation. The current work presents a modeling approach utilizing one Fatigue Damage Indicator to treat both in a unified way. The approach is implemented within the framework of the Finite Element Method. Multiaxial critical plane models with an extended damage accumulation are employed as Fatigue Indicators. Locations of fatigue crack emergence are predicted by these indicators and material degradation is utilized to model local material failure. The cyclic loading is continued on the now degraded structure and the next location prone to material failure is identified and degradation modeled. This way, fatigue crack propagation is represented by an evolving spatial zone of material failure. This propagating damage zone leads to a changing structural response of the pristine structure. By recourse to the Fatigue Damage Indicator a correlation between the number of applied load cycles and the changing structural behavior is established. Finally, the proposed approach is exemplified by cyclic bending experiments in the Low Cycle Fatigue regime. K EYWORDS . Fatigue Crack Nucleation; Fatigue Crack Propagation; Damage Indicator; Finite Element Method. Citation: Springer, M., Nelhiebel, M., Pettermann, H. E., Combined simulation of fatigue crack nucleation and propagation based on a damage indicator, Frattura ed Integrità Strutturale, 38 (2016) 155-161. Received: 27.04.2016 Accepted: 05.06.2016 Published: 01.10.2016 Copyright: © 2016 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.