Influence of Microstructural Features on the Propagation of Microstructurally Short Fatigue Cracks in Structural Steels

M. Sharaf*, J. Lian, N. Vajragupta, S. Münstermann, W. Bleck, B. Schmaling, A. Ma, A. Hartmaier

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapterScientificpeer-review

Abstract

Cyclically loaded structural steel components are usually designed to endure macroscopic stress amplitudes close to the material's endurance strength where microcracks initiate due to microstructural inhomogeneities and exhibit strong interactions with the various microstructural features in their neighborhood upon propagating. The current study presents a microstructural model with a capability to quantitatively describe the influence of microstructural features on the growth of cyclic cracks in the decisive, very early fatigue behavior stage. The FE model is based on the crystal plasticity theory and accounts for relative grain orientations. Both the extended finite element method (XFEM) and a coupled damage mechanics approach are used to describe crack opening behavior. The model is implemented to simulate real microcracking events produced in interrupted cyclic multiple-step tests under metallographic observation with temperature change measurements. Furthermore, the model is implemented on virtually created microstructures with altered grain sizes and orientations based on statistical EBSD analysis.

Original languageEnglish
Title of host publicationFatigue of Materials II
Subtitle of host publicationAdvances and Emergences in Understanding
PublisherJohn Wiley and Sons
Pages243-250
Number of pages8
ISBN (Print)9781118520932
DOIs
Publication statusPublished - 6 Nov 2012
MoE publication typeA3 Part of a book or another research book

Keywords

  • Defects
  • Endurance strength
  • Fatigue tests
  • Finite elements
  • Short cracks

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