Crystal plasticity based analysis of crack propagation at microscale by extended finite element method

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2023-1-27

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Yılmaz, Umut

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Crack propagation is conventionally treated by employing analytical methods at macroscale. Investigation of the relations between the crack propagation, dislocation movement and the crystalline grain properties in the material microscale provides better understanding of the crack propagation mechanism. In this work, the crystal plasticity constitutive model is incorporated to a commercial finite element software as an user-defined subroutine to simulate crack propagation in the material microscale. The effects of grain properties and material selection on the crack growth behavior are examined by considering different damage criteria. The extended finite element method (XFEM) is employed to analyze the crack propagation in single crystal and polycrystal structures by constructing multiple models, including pre-cracks. In these analyses, plates made of 316L stainless steel, AA2024 aluminum alloy and nickel-based supper alloy (MD2) materials with face-centered cubic crystal structures are subjected to quasi-static loading. The results of the analyses show that crack propagation behavior is dependent to the grain orientation, grain size and intrinsic material parameters such as hardening property and anisotropic stiffness.

Subject Keywords

Crystal plasticity, Crack propagation, Microstructure, Extended finite element method

URI

https://hdl.handle.net/11511/102048

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Graduate School of Natural and Applied Sciences, Thesis

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Citation Formats

U. Yılmaz, “Crystal plasticity based analysis of crack propagation at microscale by extended finite element method,” M.S. - Master of Science, Middle East Technical University, 2023.