Article
Mechanics
B. Staber, S. Forest, M. Al Kotob, M. Maziere, T. Rose
Summary: This study investigates the impact of non-smooth yield functions on material instabilities, showing that they can lead to early failure prediction compared to commonly used von Mises criterion based on structural computations. An explicit expression of the subdifferential of the non-smooth yield function is obtained, expanding upon existing results for the Tresca and Mohr-Coulomb criteria.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2021)
Article
Optics
Mohamed Yessine Jedidi, Valery Valle
Summary: This study aims to determine the plastic deformation of CP-Ti sheets during metal forming processes at room temperature, using experimental tests and digital image correlation (DIC) and Heaviside-DIC (H-DIC) techniques. The forming limit diagrams (FLDs) of CP-Ti sheets in different strain paths are determined, and the localized deformation of the sheets' materials and its impact on ductility during forming processes are investigated.
OPTICS AND LASERS IN ENGINEERING
(2023)
Article
Nanoscience & Nanotechnology
Chandra Sekhar Meduri, Jerzy Blawzdziewicz, Golden Kumar
Summary: With decreasing sample size and testing temperature, the fracture morphology of metallic glass specimens transitions from vein-pattern to completely smooth fracture surface to necking.
The size-temperature equivalence in the entire length scale can be described by considering the thermal effects in shear localization of metallic glasses.
Plastic deformation in nanoscale samples is spatially localized in embryonic shear bands, which do not mature to the propagation stage due to lack of heat content.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Chandra Sekhar Meduri, Jerzy Blawzdziewicz, Golden Kumar
Summary: The study revealed that the fracture morphology of metallic glass specimens changes with size and temperature, possibly due to thermal effects. An empirical model based on shear band heating and velocity formulations can qualitatively describe the effects of size and temperature on fracture morphology. Plastic deformation in nanoscale samples is spatially localized and does not progress to the propagation stage due to lack of heat content.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
X. Yuan, D. Sopu, J. Eckert
Summary: The local stress state in metallic glasses can be modulated without affecting their structure, leading to enhanced ductility and strain hardening during loading. The stress heterogeneity in metallic glasses results in shear band multiplication, ultimately enhancing their macroscopic ductility. Additionally, residual compressive stress significantly increases the strength of the glass and contributes to observed strain hardening.
Article
Mechanics
Hanul Hwang, Wai Hong Ronald Chan, Suhas S. Jain, Snezhana I. Abarzhi
Summary: This study systematically investigates three-dimensional Rayleigh-Taylor instability with time-varying acceleration in a finite domain, using group theory to analyze the instabilities and derive universal forms of solutions in linear and nonlinear regimes. By considering scale-dependent dynamics, different behaviors in single scale and multiscale are shown in the two regimes, with special solutions identified for bubbles and spikes from a one-parameter family of solutions. Domain confinement is found to affect velocity, curvature, and shear, while the theory provides predictions for flow field and interfacial behavior of RTI.
Article
Mechanics
Quoc Tuan Pham, Thi Bich Mac, Young-Suk Kim, Duc Toan Nguyen
Summary: This study provides a comparison of four theoretical FLC criteria for sheet metal formability evaluation and proposes an empirical suggestion to improve the accuracy of the theoretical FLC. Quantitative comparisons are made to evaluate the performance of these criteria for commonly used materials in the automotive industry, and the advantages and limitations of each model are discussed from a physical perspective.
MECHANICS BASED DESIGN OF STRUCTURES AND MACHINES
(2023)
Article
Engineering, Mechanical
Yuan Li, Guoliang Qin, Xinyi Wang, Yazhao Zhang, Zhihao Zhang
Summary: Accurately estimating the carrying capacity of pipe elbows is crucial for reducing inspections and replacements, saving time and costs. By studying the effects of defects and using plastic failure criteria, formulas for calculating the ultimate internal pressure load under various influencing factors were obtained, providing guidance for evaluating the residual strength of large-diameter elbows with defects.
ENGINEERING FAILURE ANALYSIS
(2021)
Review
Engineering, Mechanical
Khalid Zhani, Michel Darrieulat, Ahmed Chenaoui
Summary: This work investigates the behavior and instability of cold-deformed single crystals at large strains. The study demonstrates the effectiveness of Rice's criterion in predicting what happens within the grains, through the integration of theoretical calculations and experimental data.
JOURNAL OF THE BRAZILIAN SOCIETY OF MECHANICAL SCIENCES AND ENGINEERING
(2022)
Article
Nanoscience & Nanotechnology
L. Fu, C. Yang, R. Wei, X. Pei, J. Teng, D. Kong, Y. Lu, Y. Guo, T. Liu, Y. Hu, B. Yin, Z. Zhang, A. Li, L. Wang, X. Han
Summary: This study investigated the atomic-scale deformation process of AuCu nanowires with a size of 16 nm for the first time, revealing superplasticity and high strength at room temperature. The observed superplasticity was found to originate from continuous full dislocation activities and other factors, differing from previous studies on pure metals.
MATERIALS TODAY NANO
(2021)
Article
Engineering, Manufacturing
Gauri Mahalle, Nitin Kotkunde, Amit Kumar Gupta, Swadesh Kumar Singh
Summary: This study emphasizes the importance of accurately predicting the fracture limits of high strength superalloys during sheet-metal stretch forming processes. Experimental results show that the forming and fractured limits of IN718 alloy are significantly influenced by variations in processing temperatures, with higher fracture limits observed in the entire deformation region. Seven different ductile fracture models are formulated to predict the fracture loci of IN718 in EPS vs. triaxiality space, with the Oh model showing the best predictability and least average absolute error at all temperatures.
INTERNATIONAL JOURNAL OF MATERIAL FORMING
(2021)
Article
Mechanics
Lin Yuan, Qiusha Luo, Kelin Chen
Summary: This paper presents an analytical model that predicts the instability strains of bulge tests for anisotropic materials. The model takes into account the effect of radial slipping near the draw-bead, which reduces the instability strains. The accuracy and robustness of the model are validated through numerical and experimental results.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2023)
Article
Engineering, Civil
M. Cacho-Perez, J. Gomez-Carretero
Summary: This work focuses on the limit analysis or plastic calculation of slender beam planar frames using a direct method based on the Virtual Works Principle. By applying the theory of mechanisms, the plastic calculation of the structure has been systematized, leading to automatic generation of equilibrium equations. Compatibility equations for accumulated rotations in plastic hinges are presented, and the search for collapse mechanism is optimized based on energy criteria rather than trial and error.
Article
Engineering, Mechanical
Haibo Wang, Zipeng Wang, Yu Yan, Yuanhui Xu
Summary: The study proposes a modified shear failure criterion based on the original shear instability criterion to improve its accuracy in predicting the forming limit of sheet metals. Theoretical calculations using the modified criterion and different constitutive equations for TRIP780 steel and 5754O aluminum alloy sheet metals are compared with experimental results, showing that the modified criterion can predict the right area of the forming limit more reasonably. The study also analyzes the effects of pre-strain and constitutive equation on the forming limits.
CHINESE JOURNAL OF MECHANICAL ENGINEERING
(2023)
Article
Automation & Control Systems
Yongxiao Wang, Guoqun Zhao, Xiaoxue Chen, Xiao Xu
Summary: This study investigates the problem of surface cracking in the extrusion process of Al-Li alloys, and predicts the cracking position and degree through experiments and simulations. It establishes guidelines for selecting extrusion parameters.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(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
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)
Review
Materials Science, Multidisciplinary
Sunija Sukumaran, Samir Chatbouri, Didier Rouxel, Etienne Tisserand, Frederic Thiebaud, Tarak Ben Zineb
Summary: Energy harvesting using piezoelectric materials, such as PVDF, is a promising avenue for sustainable power sources. Recent research has focused on improving performance through processing methods, materials, and filler loading, as well as designing new structures to enhance piezoelectricity and overall device output. Electronic circuits play a crucial role in efficiently collecting developed charge, and advancements are being made in flexible, biomedical, and hybrid generators based on PVDF polymers.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2021)
Article
Polymer Science
Camille Thevenot, Didier Rouxel, Sunija Sukumaran, Sawsen Rouabah, Brice Vincent, Samir Chatbouri, Tarak Ben Zineb
Summary: This study focused on the flexible ferroelectric films of P(VDF-TrFE) softened by a plasticizer. The plasticizer's lubricant property helped with crystallite orientation, reducing the elastic constant and increasing remanent polarization and piezoelectric coefficient. The decrease in coercive field after annealing and the potential for industrial production make plasticized P(VDF-TrFE) a promising material for biomedical sensor applications.
JOURNAL OF APPLIED POLYMER SCIENCE
(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
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.
Article
Chemistry, Physical
Muhammad Hafiz Hassan, Jamaluddin Abdullah, Gerald Franz
Summary: In recent years, the use of CFRP with titanium and/or aluminum for aircraft construction has become more popular. Existing twist drill bits wear rapidly when drilling composite-metal stack layers, which results in poor surface quality. This study investigates the effect of twist drill geometry on hole quality and establishes correlation models to predict performance indicators.
Article
Materials Science, Multidisciplinary
Sunija Sukumaran, Samir Chatbouri, Laurent Badie, Frederic Thiebaud, Tarak Ben Zineb, Didier Rouxel
Summary: Small-scale energy harvesting for self-powered electronic devices is rapidly advancing. Researchers have proposed a simple and scalable method to combine thermal and mechanical energy harvesting using smart materials, such as the P(VDF-TrFE) piezoelectric polymer coupled with NiTi shape memory alloy (SMA), to harvest both mechanical and thermal energy.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2023)
Article
Mechanics
N. Ulff, C. Bouby, T. Ben Zineb
Summary: This paper investigates the effects of hydrogen presence on the thermo-mechanical behavior of NiTi shape memory alloys. A three-dimensional phenomenological model is formulated and solved using the finite element method. Numerical results show the significant effects of hydrogen presence in NiTi SMA.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Chemistry, Physical
Ihssen Abdelmomen, Marin Vincent, Frederic Thiebaud, Julia Budzinski, Thierry Bastogne, Tarak Ben Zineb, Marc Engels-Deutsch
Summary: Heat treatment improves the flexibility of NiTi-based endodontic files, reducing the risk of failure, ledges, and canal transportation during curved root canal preparation. This study aimed to investigate the influence of each parameter of heat treatment on the flexibility of NiTi wires and endodontic instruments. A full factorial Design of Experiment and a bending-torsion bench following ISO 3630-1 standard were used. Temperature, holding time, and cooling method were selected as contributing factors, while bending moment, hysteresis size, and stiffness during martensitic transformation were measured. Regression analysis showed that wires heated at 425 degrees C for 30 min exhibited the greatest flexibility. Heat treatment temperature was found to be the most critical factor, followed by holding time, while cooling method had a negligible effect. The regression analysis confirmed the effectiveness of the model in predicting the relationship between contributing factors and output variables.
Review
Materials Science, Multidisciplinary
Gerald Franz, Pascal Vantomme, Muhammad Hafiz Hassan
Summary: This paper reviews recent advancements in the high-performance drilling of multi-material stacks, focusing on the challenges and issues faced during the drilling process and the selection of optimized strategies. It also discusses the feasibility of alternative drilling processes for improving the hole quality of hybrid composite stacks.