Article
Crystallography
Ji He, Yishuang Feng
Summary: This paper proposes a new method based on the bifurcation phenomenon in strain evolution to detect the onset of localized necking through DIC measurements, eliminating the need for derivative calculation. The method provides satisfactory forming limit results and can be used as an alternative method to determine the forming limit diagram (FLD).
Article
Engineering, Manufacturing
Mitsutoshi Kuroda
Summary: This article describes the fundamentals and importance of the yield surface vertex effects in plastic flow localization predictions. The theoretical significance, experimental evidence, and modeling strategies of the yield surface vertices are presented. Previous studies on plastic flow localization analyses incorporating the yield surface vertex effects are reviewed. The article also highlights the limitations of conventional plasticity theories in predicting shear bands and discusses recent developments in gradient-enhanced vertex-type plasticity and crystal plasticity theories.
INTERNATIONAL JOURNAL OF MATERIAL FORMING
(2022)
Article
Mathematics, Applied
Pedro Parra-Rivas, Alan R. Champneys, Fahad Al Saadi, Damia Gomila, Edgar Knobloch
Summary: This study provides a unified explanation for the bifurcation diagrams of localized structures in various contexts, such as nonlinear optics, fluid mechanics, and mathematical biology. The study reveals a singularity structure that exhibits a rich bifurcation pattern of localized structures, including nested periodic patterns generated by standard homoclinic snaking and collapsed snaking structure of stationary domains embedded in homogeneous solutions.
SIAM JOURNAL ON APPLIED DYNAMICAL SYSTEMS
(2023)
Article
Materials Science, Multidisciplinary
K. E. N'souglo, K. Kowalczyk-Gajewska, M. Marvi-Mashhadi, J. A. Rodriguez-Martinez
Summary: In this paper, the effect of initial texture on multiple necking patterns in ductile metallic rings subjected to rapid radial expansion was investigated using finite element calculations. The material behavior was modeled using the elasto-viscoplastic single crystal constitutive model developed by Marin specialIntscript. The polycrystalline microstructure of the ring was generated using random Voronoi seeds. The results showed that the spatial distribution of grains, grain size, and initial texture have significant effects on the formation of necks.
MECHANICS OF MATERIALS
(2023)
Article
Mathematics, Interdisciplinary Applications
Jose Lara, Paul Steinmann
Summary: It is common practice to use visco-plastic regularization to approximate rate-independent behavior in computational investigations of plasticity. However, there is a numerical limit to the regularization parameter, which may be exacerbated by complex material models and critical values of material parameters. Insufficient regularization can introduce artificial rate-dependency and lead to behavior that is mistakenly attributed to the material model. In this study, the problem of an infinite strip under shear loading is numerically solved using a visco-plastic regularized gradient crystal plasticity formulation. The required accuracy of the rate-dependent approximation is found to vary with the type of loading.
COMPUTATIONAL MECHANICS
(2023)
Article
Automation & Control Systems
Muhammad Waqar Nasir, Hocine Chalal, Farid Abed-Meraim
Summary: The aim of this study is to develop a numerical tool for the theoretical prediction of forming limit diagrams. The proposed tool is based on the Marciniak and Kuczynski imperfection approach and the Gurson-Tvergaard-Needleman damage model, implemented in MATLAB under plane-stress conditions. The results show that the forming limit diagram obtained using the bifurcation theory provides an upper bound compared to the predictions of the Marciniak and Kuczynski imperfection approach. Additionally, the predicted ductility limits decrease as the magnitude of initial imperfection increases, with the most significant decrease observed for balanced biaxial tension.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Civil
Wen-Feng Chen, Yao-Peng Liu, Zuo-Lei Du, Rui Bai, Siu-Lai Chan
Summary: A new consistent analytical model for second-order direct analysis of steel structures with tapered members is proposed in this paper, considering both symmetric and asymmetric variations. The model takes into account initial geometrical imperfections and residual stress, eliminating the need for the traditional effective length method. The proposed method provides a safer and more economical design for tapered structures without the assumption of effective length factor.
Article
Engineering, Multidisciplinary
Alexander Niehueser, Jorn Mosler
Summary: The challenges of classic rate-independent crystal plasticity models and the determination of active slip systems are still areas of active research. This paper presents a new interior-point algorithm for rate-independent crystal plasticity at finite strains, which effectively solves optimization problems by utilizing interior-point methods. The efficiency and robustness of the algorithm are demonstrated through numerical examples and comparisons with other formulations.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2023)
Article
Mechanics
J. L. Dequiedt, C. Denoual
Summary: The study revealed that the development of plastic strain localization in a stretching tantalum sheet is influenced by grain size, with large grains showing early localization while smaller grains exhibit larger wavelength strain modulations before neck formation.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Article
Nanoscience & Nanotechnology
Bohye Jeon, Min -Su Lee, Tea -Sung Jun, Youngung Jeong
Summary: This study investigated a commercially pure titanium sample using an elasto-visco-plastic self-consistent polycrystal model. The temperature-dependent plastic deformation behavior was described using a dislocation density-based hardening model. The model successfully reproduced various experimental behaviors and provided an in-depth interpretation of the mechanical behavior of alpha-titanium under different temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2024)
Article
Materials Science, Multidisciplinary
C. Senac, J. Hure, B. Tanguy
Summary: Ductile fracture in metallic alloys occurs through the growth and coalescence of cavities. Different forms of coalescence can develop, including internal necking, coalescence in columns, and void sheeting. This study investigates the transition from homogeneous yielding to inhomogeneous yielding modes in anisotropic porous materials, considering plastic anisotropy and void shape effects. Analytical yield criteria obtained through kinematic limit analysis are compared to numerical simulations, showing qualitative agreement. Additionally, a homogenized model for Hill porous materials is developed, incorporating evolution laws for microstructural parameters derived from sequential limit analysis.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2023)
Article
Nanoscience & Nanotechnology
Yilun Xu, Tianhong Gu, Jingwei Xian, Finn Giuliani, T. Ben Britton, Christopher M. Gourlay, Fionn P. E. Dunne
Summary: The mechanical properties and temperature sensitivity of beta-Sn single crystals and polycrystalline beta-Sn-rich alloys have been investigated using a combination of experimental and numerical methods. The results provide insights into the behavior of electronic solders under thermomechanical loading.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Engineering, Multidisciplinary
T. Manik, H. M. Asadkandi, B. Holmedal
Summary: A new stable return-mapping algorithm is proposed for crystal-plasticity solutions, which uses a regularized yield surface with very large exponents. The algorithm achieves good numerical stability and is implemented as a fast and stable implicit method in finite element software for simulations of both single crystals and polycrystalline materials.
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2022)
Article
Engineering, Industrial
Mohamed Ben Bettaieb, Farid Abed-Meraim
Summary: This study investigates the impact of adhering an elastomer substrate to metal sheets on the ductility of the metal layer. Numerical analysis is used to predict the localization of plastic strain within the metal layer. The results show that the ductility limits predicted by the non-associated elasto-plastic model are lower than those determined by an associated plasticity model, and that adhering an elastomer layer can delay the onset of plastic strain localization.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Engineering, Mechanical
Muhammad Waqar Nasir, Hocine Chalal, Farid Abed-Meraim
Summary: This paper investigates the combination of plastic instability criteria based on bifurcation theory with the GTN damage model for predicting diffuse and localized necking. The hierarchical prediction order of different instability criteria is consistent, with the GB criterion providing a lower bound and the LOE criterion representing an upper bound in necking prediction.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Engineering, Mechanical
Mohamed Jebahi, Lei Cai, Farid Abed-Meraim
INTERNATIONAL JOURNAL OF PLASTICITY
(2020)
Article
Mechanics
Hocine Chalal, Farid Abed-Meraim
INTERNATIONAL JOURNAL OF APPLIED MECHANICS
(2019)
Article
Engineering, Mechanical
Jianchang Zhu, Mohamed Ben Bettaieb, Farid Abed-Meraim
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2020)
Article
Engineering, Mechanical
M. Y. Jedidi, M. Ben Bettaieb, F. Abed-Meraim, M. T. Khabou, A. Bouguecha, M. Haddar
INTERNATIONAL JOURNAL OF PLASTICITY
(2020)
Article
Engineering, Industrial
Mohamed Ben Bettaieb, Farid Abed-Meraim
Summary: This study investigates the impact of adhering an elastomer substrate to metal sheets on the ductility of the metal layer. Numerical analysis is used to predict the localization of plastic strain within the metal layer. The results show that the ductility limits predicted by the non-associated elasto-plastic model are lower than those determined by an associated plasticity model, and that adhering an elastomer layer can delay the onset of plastic strain localization.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2021)
Article
Engineering, Multidisciplinary
J. Paux, M. Ben Bettaieb, H. Badreddine, F. Abed-Meraim, C. Labergere, K. Saanouni
COMPUTER METHODS IN APPLIED MECHANICS AND ENGINEERING
(2020)
Article
Computer Science, Interdisciplinary Applications
J. C. Zhu, M. Ben Bettaieb, F. Abed-Meraim
Summary: This paper presents a comparative study of three numerical techniques for computing macroscopic tangent moduli and emphasizes their practical implementations in ABAQUS/Standard finite element code. The reliability, accuracy, and ease of implementation of these techniques are evaluated through numerical examples, and the condensation method is found to be the most reliable and efficient.
ENGINEERING WITH COMPUTERS
(2022)
Article
Mechanics
Muhammad Waqar Nasir, Hocine Chalal, Farid Abed-Meraim
Article
Materials Science, Multidisciplinary
J. C. Zhu, M. Ben Bettaieb, F. Abed-Meraim
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2020)
Article
Engineering, Mechanical
Muhammad Waqar Nasir, Hocine Chalal, Farid Abed-Meraim
Summary: This paper investigates the combination of plastic instability criteria based on bifurcation theory with the GTN damage model for predicting diffuse and localized necking. The hierarchical prediction order of different instability criteria is consistent, with the GB criterion providing a lower bound and the LOE criterion representing an upper bound in necking prediction.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Mathematics, Applied
Moncef Aouadi, Mohamed Ben Bettaieb, Farid Abed-Meraim
Summary: This paper studies the qualitative and numerical properties of new equations incorporating the coupled effects of thermal elastic-plastic theory with microtemperatures. It establishes conditions for energy dissipation and proves the well-posedness of the one-dimensional plastic flow problem. The associated C0-semigroup is shown to be non-analytical in general, except for a special case, with solutions maintaining exponential stability. A numerical tool based on the finite element method is developed to validate the model and highlight its capability, with a particular focus on elastoplastic behavior.
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK
(2021)
Article
Automation & Control Systems
Muhammad Waqar Nasir, Hocine Chalal, Farid Abed-Meraim
Summary: The aim of this study is to develop a numerical tool for the theoretical prediction of forming limit diagrams. The proposed tool is based on the Marciniak and Kuczynski imperfection approach and the Gurson-Tvergaard-Needleman damage model, implemented in MATLAB under plane-stress conditions. The results show that the forming limit diagram obtained using the bifurcation theory provides an upper bound compared to the predictions of the Marciniak and Kuczynski imperfection approach. Additionally, the predicted ductility limits decrease as the magnitude of initial imperfection increases, with the most significant decrease observed for balanced biaxial tension.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Mechanical
J. Paux, M. Ben Bettaieb, H. Badreddine, F. Abed-Meraim, C. Labergere, K. Saanouni
Summary: This investigation introduces an advanced phenomenological approach that combines the computational efficiency of classical phenomenological plasticity models with the accuracy and high resolution of multiscale crystal plasticity schemes. The newly developed constitutive framework in ABAQUS/Standard FE code allows for accounting initial and induced plastic anisotropy, isotropic nonlinear hardening, and full coupling with isotropic ductile damage, providing a robust and reliable model for predicting material behavior under different loading conditions.
INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES
(2021)
Article
Mechanics
H. Tian, M. Potier-Ferry, F. Abed-Meraim
Summary: Dealing with the wrinkling of thin structures can be challenging, especially for very thin membranes in a slack state; a new numerical procedure based on a double Taylor series is presented in this paper, which combines path following techniques and discretization methods for evaluation.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Article
Crystallography
Lei Cai, Mohamed Jebahi, Farid Abed-Meraim
Summary: This paper investigates the abilities and limitations of strain gradient crystal plasticity (SGCP) theories in capturing different kinds of localization modes in single crystals. By simulating several single crystal localization problems with different slip system configurations, the study demonstrates the good capabilities of the applied model in regularizing various types of localization bands.