## A Multi-scale temporal integration scheme for viscoplatic solids subjected to fatigue deterioration

- Using a continuum mechanics framework for lifetime prediction requires numerical integration of evolving damage until the onset of failure. The primary challenge for the simulation of structural fatigue failure is caused by the enormous computational costs due to cycle by cycle temporal integration throughout the whole loading history, which is in the order of 10^3 - 10^7 cycles. As a consequence, most approaches circumvent this problem and use an empirical method such as Wöhler curves. They are well suited for approximation of the lifetime, but they are not capable to capture a realistic degradation of the material with a redistribution of the stresses. The main objective of the paper is to provide a technique for the long time response of a finite element (FE) model while reducing computational costs. A multi-scale temporal integration scheme is proposed, which adapts the conventional FE method for realistic modeling of deterioration in a structure subjected to cyclicUsing a continuum mechanics framework for lifetime prediction requires numerical integration of evolving damage until the onset of failure. The primary challenge for the simulation of structural fatigue failure is caused by the enormous computational costs due to cycle by cycle temporal integration throughout the whole loading history, which is in the order of 10^3 - 10^7 cycles. As a consequence, most approaches circumvent this problem and use an empirical method such as Wöhler curves. They are well suited for approximation of the lifetime, but they are not capable to capture a realistic degradation of the material with a redistribution of the stresses. The main objective of the paper is to provide a technique for the long time response of a finite element (FE) model while reducing computational costs. A multi-scale temporal integration scheme is proposed, which adapts the conventional FE method for realistic modeling of deterioration in a structure subjected to cyclic loading. For a particular case of two-scale temporal homogenization, the displacement field is assumed to satisfy scale separation: a short time scale arises from the oscillatory loading and a long time scale is due to the slow response relating to yielding and damage evolution. The original boundary value Problem (BVP) is approximated by the time-Independent BVPs on the short time scale. Alternation of the displacement field on the long time scale is correlated with the damage evolution by means of the adaptive cycle jump method. The significant acceleration of FE simulations is demonstrated for a constitutive damage model where the progressive damage accumulation under fatigue loading is driven by viscoplastic deformation.…

Autoren/innen: | Vitaliy Kindrachuk |
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Koautoren/innen: | Jörg F. Unger |

Dokumenttyp: | Vortrag |

Veröffentlichungsform: | Präsentation |

Sprache: | Englisch |

Jahr der Erstveröffentlichung: | 2016 |

Organisationseinheit der BAM: | 5 Werkstofftechnik |

5 Werkstofftechnik / 5.2 Experimentelle und modellbasierte Werkstoffmechanik | |

DDC-Klassifikation: | Technik, Medizin, angewandte Wissenschaften / Ingenieurwissenschaften / Ingenieurwissenschaften und zugeordnete Tätigkeiten |

Freie Schlagwörter: | Fatigue |

Themenfelder/Aktivitätsfelder der BAM: | Material |

Veranstaltung: | ECCOMAS 2016 |

Veranstaltungsort: | Crete, Greece |

Beginndatum der Veranstaltung: | June 5th |

Enddatum der Veranstaltung: | June 10th |

Verfügbarkeit des Volltexts: | Volltext-PDF im Netzwerk der BAM verfügbar ("Closed Access") |

Datum der Freischaltung: | 13.12.2016 |

Referierte Publikation: | Nein |