Article
Engineering, Mechanical
K. C. Kincaid, D. W. MacPhee, G. G. Stubblefield, J. B. Jordon, T. W. Rushing, P. G. Allison
Summary: In this study, a finite volume simulation framework developed, validated, and employed the Additive Friction Stir Deposition (AFSD) process. The simulation showed excellent agreement between the predicted and measured temperature data and provided a good qualitative prediction of the overall build layer morphology. Further analysis revealed the temperature variation in the build direction and determined the relative importance of various modes of heat input and cooling.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Materials Science, Multidisciplinary
Sandipan Paul, Alan D. Freed
Summary: In this study, a constitutive model for elastic-plastic materials is developed using scalar, conjugate, stress-strain, base pairs in a finite deformation setting. The alternative QR decomposition of the deformation gradient allows for direct measurement of Laplace stretch and its plastic contributions. This model has implications for the construction of constitutive models for a wider class of materials.
JOURNAL OF THE MECHANICS AND PHYSICS OF SOLIDS
(2021)
Article
Chemistry, Physical
Maciej Wedrychowicz, Wladyslaw Papacz, Janusz Walkowiak, Adam Bydalek, Andrzej Piotrowicz, Tomasz Skrzekut, Jagoda Kurowiak, Piotr Noga, Miroslaw Kostrzewa
Summary: This article discusses the possibility of obtaining a solid plate from waste cable sheaths through mechanical recycling, specifically grinding, plasticising and pressing. The experiment shows that the resulting solid plate does not significantly differ from the input material in terms of mechanical strength, indicating the successful application of this promising waste cable processing method in industrial practice.
Review
Chemistry, Physical
Maciej Wedrychowicz, Jagoda Kurowiak, Tomasz Skrzekut, Piotr Noga
Summary: Civilization and technical progress rely on energy, with electricity demand increase driving the need for cable recycling. There are currently vast possibilities and scientific efforts to recycle cables, aligning with global climate policies.
Article
Engineering, Mechanical
Mattia Utzeri, Ajay Bhagavatam, Edoardo Mancini, Guru Dinda, Marco Sasso, Golam Newaz
Summary: This study investigated the compression behavior of Inconel 625 fabricated by LMD, proposing a modified mechanical model to describe its specific mechanical properties, and used multiple models to represent the effects of strain rate and temperature on material properties.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Engineering, Mechanical
Saibal Kanchan Barik, R. Ganesh Narayanan, Niranjan Sahoo
Summary: This study focused on evaluating failure strain and fracture pattern during shock tube impact forming of 1.5 mm thick AA 5052-H32 sheet through numerical and experimental methods. The modified Johnson-Cook model showed better flow stress predictability, and combining Cockcroft-Latham, Brozzo, and Freudenthal failure models with Johnson-Cook and modified Johnson-Cook flow stress models led to fair agreement with experimental data in predicting failure strain and necking location.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2021)
Article
Mechanics
Sandipan Paul, Alan D. Freed, Laszlo Szabo
Summary: In this paper, the Eshelby energy-momentum tensor is studied using QR kinematics, which is obtained by upper-triangular decomposition of the deformation gradient. The paper introduces the relationship between driving force attributes and dissipative strain attributes, and proposes a method for constitutive formulation. Furthermore, a classical plasticity model is derived to illustrate the role of driving force attributes.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Engineering, Mechanical
C. Santus, T. Grossi, L. Romanelli, M. Pedranz, M. Benedetti
Summary: The study proposes an optimization method based on fitting the global properties of the cyclic curves to experimental data to determine the stress-strain behavior of materials under multiaxial cyclic loadings. The method provides an accurate description of the material behavior at a low computational cost. Experimental tests on various materials demonstrate the effectiveness of the proposed method.
INTERNATIONAL JOURNAL OF PLASTICITY
(2023)
Article
Materials Science, Multidisciplinary
Xuli Liu, Yidong Wu, Yansong Wang, Jinbin Chen, Rui Bai, Lei Gao, Zhe Xu, William Yi Wang, Chengwen Tan, Xidong Hui
Summary: This study presents a new type of NiCoFeCrMoW high entropy alloys (HEAs) with enhanced deformability and strength. The phase structure, quasi-static tensile, dynamic compression, and deformation mechanism of these HEAs were systematically investigated. The results show that FCC or FCC + mu dual phases were formed in the HEAs, depending on the content of Mo and W and the annealing temperature. The HEAs exhibited excellent quasi-static tensile and dynamic compression properties, and the dynamic deformation mechanism was attributed to the regulation of stacking fault energy and Peierls barrier, leading to the formation of abundant nanoscale deformation twins and microbands during high strain rate compression. The synergistic microbanding and twinning effectively contributed to the enhanced dynamic deformability and strengthening effect.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Stephanie A. Pitts, Wen Jiang, Davide Pizzocri, Erin I. Barker, Hussein M. Zbib
Summary: In this study, a continuum dislocation density (CDD) crystal plasticity model is proposed to capture the embrittlement mechanism of RPV steels under radiation. The model successfully captures the interactions among dislocations and the stress response. Experimental results demonstrate the accurate prediction of the mechanical behavior of alpha-iron using this model.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2022)
Article
Multidisciplinary Sciences
Yugen Li, Huimei Zhang, Min Chen, Xiangzhen Meng, Yanjun Shen, Hui Liu, Yani Lu
Summary: This study theoretically assessed the effect of initial stress and structure on the mass damage of rock mass under load. A multi-factor coupling damage constitutive model and a jointed rock mass strength criterion were established to accurately predict damage characteristics and strength. The results showed that the joint angle, minimum principal stress, volume stress, shear stress, and joint dip angle influenced the strength of the rock mass. Compared to other methods, this approach better reflected the strength and influencing factors of jointed rock mass.
SCIENTIFIC REPORTS
(2022)
Article
Mechanics
Shijie Xie, Zhenyu Han, Hang Lin
Summary: In this study, an exponential model based on the effective medium theory is proposed to describe the influence of the crack closure effect on the constitutive relation of rock materials. The crack deformation is characterized by natural strain, and the model can simulate the stress-strain curves of rocks under different compression conditions.
INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES
(2022)
Article
Computer Science, Interdisciplinary Applications
Yizhao Gao, Qingshuo Hao, Peng Yu, Yuzhen Yu, He Lv
Summary: This study proposes a new constitutive model for granular soils, considering two types of volume variations and the state dependency of material density. The model includes compression and unloading curves considering grain crushing, and can accurately describe the stress-dilatancy relation under different experimental conditions.
COMPUTERS AND GEOTECHNICS
(2023)
Article
Engineering, Mechanical
Janos Plocher, Vito L. Tagarielli, Ajit Panesar
Summary: In this study, lattice structures with uniform and graded relative density are manufactured using three-dimensional printing. The elastic-plastic compressive response of these structures is measured, and finite element simulations are used to analyze the relationship between their constitutive response and relative density. The findings can be utilized in topology optimization to enhance the performance of 3D-printed FGL components.
JOURNAL OF ENGINEERING MATERIALS AND TECHNOLOGY-TRANSACTIONS OF THE ASME
(2023)
Article
Engineering, Geological
Yixing Yuan, Andrew J. Whittle
Summary: This paper presents a novel elastoviscoplastic constitutive model, MIT-SR, which is capable of describing a wide range of time-dependent characteristics observed in clays. The key component of the model is an evolution equation that attributes viscoplastic deformations to an internal strain rate state variable, driven by external straining actions. The model showcases versatility in representing time-dependent behavior and promising capability in describing rate-effects under cyclic shear.
INTERNATIONAL JOURNAL FOR NUMERICAL AND ANALYTICAL METHODS IN GEOMECHANICS
(2021)
Article
Materials Science, Multidisciplinary
G. Ranjbari, A. Doniavi, M. Shahbaz, R. Ebrahimi
Summary: The study utilizes finite element analysis and response surface methodology to investigate the effects of geometrical parameters in vortex extrusion die design on strain inhomogeneity and processing load in Al-Mg-Si alloy.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
M. Shahbaz, N. Pardis, J. Moon, R. Ebrahimi, H. S. Kim
Summary: Vortex extrusion uses a novel designed stationary die to impose intense strain to materials, resulting in torsional deformation and reduction in area. By utilizing a streamline approach to design the VE die, processed samples exhibit a higher fraction of high-angle grain boundaries and significantly improved tensile properties compared to conventional extrusion methods.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Materials Science, Multidisciplinary
S. Hadi, F. Rahimzadeh Lotfabad, M. H. Paydar, R. Ebrahimi
Summary: In this study, a mathematical analysis using the slab method was used to derive a formula for calculating the average hydrostatic pressure in the compressive stage of the HPT process. Experimental results confirmed the accuracy of the analytical calculations, showing that with appropriate selection of sample volume and consideration of equipment capacity, the desired average hydrostatic pressure can be achieved.
METALS AND MATERIALS INTERNATIONAL
(2021)
Article
Mathematics
Ramin Ebrahimi, Alireza Nasr-Isfahani
Summary: This article proves that the category of finitely presented functors mod-M modulo the subcategory of effaceable functors mod(0)-M in a small n-abelian category M has an n-cluster tilting subcategory which is equivalent to M.
INTERNATIONAL MATHEMATICS RESEARCH NOTICES
(2022)
Article
Chemistry, Physical
F. Khodabakhshi, O. Ekrt, M. Abdi, A. P. Gerlich, M. Mottaghi, R. Ebrahimi, M. Nosko, G. Wilde
Summary: An advanced SPD method called accumulative fold-forging was used to produce layered nanostructured MgNi alloys with superior hydrogen storage capacity. Adjusting the structure can control hydrogen uptake and release characteristics, while refining the grain structure to the nano-scale range can further enhance hydrogen absorption capacity.
INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
(2022)
Article
Materials Science, Multidisciplinary
M. Abdi, R. Ebrahimi
Summary: In this study, multi-step processing of an as-cast AZ91 alloy using twin parallel channel angular extrusion was investigated. The results showed that processing for three passes at temperatures of 340, 300, and 250 degrees C resulted in the most uniform and fine microstructure with reduced grain size and dislocation density. The average hardness value also significantly improved compared to the initial value.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2022)
Article
Engineering, Mechanical
Ramin Ebrahimi, Faraz Rahimzadeh Lotfabad
Summary: This study presents a comprehensive mathematical analysis of the bulge test, focusing on addressing potential misinterpretations of the test results by users. The consistency between experimental data and mathematical models confirms the accuracy of this method.
IRANIAN JOURNAL OF SCIENCE AND TECHNOLOGY-TRANSACTIONS OF MECHANICAL ENGINEERING
(2022)
Article
Polymer Science
Maryam Ghobadi, Faraz Rahimzadeh Lotfabad, Seyed Mojtaba Zebarjad, Ramin Ebrahimi
Summary: The main focus of this investigation is to quantitatively analyze the opposing effect of filler on the desired properties of fabricated composite specimens. Through experiments, HDPE-BN composites with different proportions of BN were prepared, and their density and thermal conductivity were measured. The multi-objective optimization method was used to determine the optimal BN content, and the relative importance of these properties was evaluated using the entropy method. The study found that density has a more determinative role in the efficiency of a particular filler in circumstances where both thermal conductivity and density have practical importance.
POLYMERS FOR ADVANCED TECHNOLOGIES
(2022)
Article
Chemistry, Physical
Keyvan Mirzaee Fashalameh, Zahra Sadeghian, Ramin Ebrahimi
Summary: In this study, a planar multi-layer solid oxide fuel cell (SOFC) was successfully fabricated using slurry-based 3D printing. The results showed that the use of hierarchically macromesopores structure can increase power density, and electrochemical performance can be improved by modifying the geometry of the layers.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Review
Materials Science, Multidisciplinary
Ramin Ebrahimi, Faraz Rahimzadeh Lotfabad
Summary: Simple shear extrusion is a severe plastic deformation technique designed in 2009 to obtain ultrafine-grained materials. Extensive research has been conducted to introduce and explore the characteristics of this technique, as well as investigate its potential for industrialization.
MATERIALS SCIENCE AND TECHNOLOGY
(2023)
Article
Crystallography
Mohammad Abdi, Ramin Ebrahimi, Ebad Bagherpour
Summary: In this study, the developed SPD processing technique of Twin Parallel Channel Angular Extrusion (TPCAE) was utilized to enhance the hydrogen storage properties of AZ91 cast alloy. By conducting hydrogen absorption and desorption tests kinetically at different temperatures, it was found that TPCAE processing significantly improved the absorption kinetic and desorption rate of the alloy.
Review
Medicine, General & Internal
Ali Emadi Torghabe, Ramin Ebrahimi, Zohreh Pishevar Feizabad
Summary: We report a rare case of synovial sarcoma of the prostate in a 30-year-old male patient, who presented with advanced metastasis at diagnosis and had a poor prognosis.
CLINICAL CASE REPORTS
(2022)
Article
Mathematics
Ramin Ebrahimi
Summary: This article investigates the invertibility condition of the natural map qiX,A: ExtiA(X, A) to ExtiA/C(q(X), q(A)) for every object X and A, and every i in {0, 1, ..., k} in a essentially small abelian category A with a given Serre subcategory C. An application of the main theorem is also provided.
JOURNAL OF ALGEBRA
(2023)
Article
Engineering, Mechanical
Zahra Ramezani Anbaran, Faraz Rahimzadeh Lotfabad, Ramin Ebrahimi, Habib Danesh Manesh
Summary: In this investigation, a previously proposed phenomenological model is generalized in terms of its mathematical form and the yield function used. The Al 1050 material is chosen as the model material, and its tensile properties and forming limit curve (FLC) are obtained through annealing and tests. The constants of the generalized model are obtained by curve fitting, and the model's accuracy is improved at the cost of losing a single mathematical expression for both branches of the FLC. The study also shows that using the Hosford yield criterion yields better predictions compared to using the von Mises yield criterion.
JOURNAL OF STRAIN ANALYSIS FOR ENGINEERING DESIGN
(2023)
Meeting Abstract
Immunology
S. Cox, E. Grebe, A. Kintu, Y. Shao, F. Matova Kiweewa, Z. Lukyamuzi, F. Kiweewa, S. Facente, R. Ebrahimi, C. Carter, C. Callebaut, J. Baeten, M. Das
JOURNAL OF THE INTERNATIONAL AIDS SOCIETY
(2022)
