Microstructure modeling and crystal plasticity simulations for the evaluation of fatigue crack initiation in α-iron specimen including an elliptic defect

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING

卷:695

Article

Briffod, Fabien¹  Shiraiwa, Takayuki¹  Enoki, Manabu¹ 

[1] Univ Tokyo, Dept Mat Engn, Bunkyo Ku, Japan 7-3-1 Hongo, Tokyo 1138656, Japan

关键词: Fatigue crack initiation;    Crystal plasticity;    Microstructure-sensitive modeling;    Tessellation;    EBSD;   

DOI  :  10.1016/j.msea.2017.04.030

来源: Elsevier

【 摘 要 】

In this study, fatigue crack initiation in pure alpha-iron is investigated through a microstructure-sensitive framework. At first, synthetic microstructures are modeled based on an anisotropic tessellation that accounts for the information of the grains morphology extracted from electron backscatter diffraction (EBSD) analysis. Low-cycle fatigue experiments under strain-controlled conditions are conducted in order to calibrate a crystal plasticity model and a J(2) model including isotropic and kinematic hardening. A critical plane fatigue indicator parameter (FIP) based on the Tanaka-Mura model is then presented to evaluate the location and quantify the driving force for the formation of a crack. The FT is averaged over several potential crack paths within each grain defined by the intersection between a given slip plane and the plane of the model thus accounting for both the lattice orientation and morphology of the grain. Several fatigue simulations at various stress amplitudes are conducted using a sub-modeling technique for the attribution of boundary conditions on the polycrystalline aggregate models including an elliptic defect. The influence of the microstructure attributes and stress level on the location and amplitude of the PIP are then quantified and discussed.

【 授权许可】

Free