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A new crystal plasticity model incorporating precipitation strengthening to simulate tensile deformation behavior of AA2024 alloy

Singh Lakhwinder, Ha Sangyul, Vohra Sanjay, Sharma Manu

Archives of Civil and Mechanical Engineering

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2023

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Vol. 23, no. 3

art. no. e155, 2023

EN

In this work, a constitutive model is developed by incorporating precipitation strengthening into a dislocation-density-based crystal plasticity (CP) model to simulate the mechanical properties of 2024 aluminium alloy (AA). The proposed model considers the contributions of solid solution strengthening and strengthening from dislocation–precipitate interactions into the total slip resistance along with the forest hardening due to dislocation–dislocation interactions. A term accounting for the multiplication of dislocations due to their interactions with the non-shearable precipitates in the alloy is incorporated in the hardening law. The developed precipitation strengthening-based CP model is implemented into the crystal plasticity finite element method (CPFEM) for simulating the macroscopic mechanical behavior of AA2024-T3 alloy for uniaxial tension over various strain rates. The macroscopic response of the polycrystal representative volume element (RVE) used for simulations is computed using computational homogenization. The effect of meshing resolution on the RVE response is studied using four different mesh discretizations. Predictions of the macroscopic behavior by the developed model are in good agreement with the experimental findings. Additionally, the contribution of model parameters to the total uncertainty of the predicted stress has been assessed by conducting a sensitivity analysis. A parametric analysis with different precipitate radii and volume fractions has been done for finding the effect of precipitates on the macroscopic and localized deformation.

2

Application of crystal plasticity model for simulation of polycrystalline aluminum sample behavior during plain strain compression test

Wajda W., Madej Ł., Paul H.

Archives of Metallurgy and Materials

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2013

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Vol. 58, iss. 2

493--496

EN

Capabilities of crystal plasticity finite element (CPFE) model in application to modeling polycrystalline aluminum sample behavior during plain strain compression test are discussed within the present work. To simplify analysis of material behavior during plain strain compression the aluminum specimen is composed of only three grains, both in experiment and numerical simulation. To reconstruct appropriate grains morphology a digital material representation (DMR) technique is used. The predicted/calculated values of loads and pole figures are compared with the experimental data. Calculated results remain in good agreement with experimental data what highlight predictive capabilities of the proposed approach in modeling material behavior under loading conditions. The conclusions regarding model capabilities and possible improvements during further work are also drawn in the paper.

PL

W artykule przedstawiono możliwości opisu zachowania umocnieniowego, polikrystalicznej próbki aluminiowej ściskanej w płaskim stanie odkształcenia, z wykorzystaniem modelu plastyczności kryształu i Metody Elementów Skończonych. Ściskana próbka składała się z trzech ziaren, co ułatwiło analizę jej zachowania umocnieniowego oraz weryfikacje wyników numerycznych. Zastosowanie modelu plastyczności kryształów do symulacji zachowania odkształceniowego próbek polikrystalicznych wymaga odwzorowania rzeczywistej (mikro)struktury próbki, do czego wykorzystano koncepcje Cyfrowej Reprezentacji Materiału (DMR - ang. Digital Material Representation). Metoda DMR umożliwia rekonstrukcje morfologii oraz określenie początkowej orientacji ziaren w symulacji. Wyniki obliczeń w postaci figur biegunowych oraz naprężenia w funkcji odkształcenia zostały porównane z wynikami doświadczalnymi. Obliczone wyniki wykazują dobra zgodność z doświadczeniem. W artykule omówiono wyniki porównania oraz przedstawiono wnioski głównie dotyczące kierunku udoskonalenia modelu w dalszej pracy.

3

A new approach to the analysis of polycrystal plasticity

Peng X., Fan J.

Archives of Mechanics

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2000

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Vol. 52, nr 1

103-125

EN

When a polycrystal is subjected to inelastic deformation, there inevitably exist residual microstress fields in a polycrystalline material due to its nonhomogeneous morphology. The energy stored in these microstress fields may partly be released and influence the material behavior during subsequent inelastic deformation. Correspondingly, a simple mechanical model is introduced to formulate the constitutive equation for a slip system and the hardening law for single crystal. The corresponding approach for the analysis of polycrystalline materials is obtained based on KBW's self-consistent theory. The proposed approach employs no yield criterion and the corresponding numerical analysis is greatly simplified because it involves no additional process for determination of the activation of slip systems and slip direction. A mixed averaging approach is used in polycrystalline plasticity analysis. The response of 316 stainless steel subjected to typical biaxial nonproportional plastic strain cycling is described and the validity of the proposed approach is demonstrated by the satisfactory agreement between the calculated result and experimental observation.