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large-plastic-deformation
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Modelling of powder forming processes in transient-dynamic analysis of large plastic deformations
, Article Advanced Materials Research, 13 July 2011 through 16 July 2011 ; Volume 445 , July , 2012 , Pages 362-367 ; 10226680 (ISSN) ; 9783037853467 (ISBN) ; Biabanaki, S. O. R ; Parvaneh, S. M ; Turkish Airlines; TTNET; Gedik Holding; Istanbul Development Agency ; Sharif University of Technology
2012
Abstract
In this paper, a transient-dynamic analysis is presented for large deformation of powder forming process. The technique is employed using the contact friction algorithm and plasticity behavior of powder. The contact algorithm is applied by imposing the contact constraints and modifying the contact properties of frictional slip through the node-to-surface contact algorithm. A double-surface cap plasticity model is used for highly nonlinear behavior of powder. In order to predict the non-uniform density and stress distributions during powder die-pressing, the numerical schemes are examined for accuracy and efficiency in modeling of a set of powder components
3D dynamic modeling of large plastic deformations in powder die-pressing
, Article Proceedings of the 10th International Conference on Technology of Plasticity, ICTP 2011, 25 September 2011 through 30 September 2011, Aachen ; September , 2011 , Pages 1010-1015 ; 9783514007840 (ISBN) ; Biabanaki, S. O. R ; Parvaneh, S. M ; Sharif University of Technology
2011
Abstract
In this paper, a computational algorithm is presented in three-dimensional dynamic modeling of powder compaction processes. The contact node-to-surface algorithm is employed to impose the contact constraints in large deformation frictional contact, and the contact frictional slip is modified by the Coulomb friction law to simulate the frictional behavior between the rigid punch and the work-piece. The 3D nonlinear contact friction algorithm is employed together with a double-surface cap plasticity model within the framework of large FE deformation in order to predict the non-uniform relative density distribution during the dynamic simulation of powder die-pressing. Finally, the performance...
X-FEM modeling of large plasticity deformation; A convergence study on various blending strategies for weak discontinuities
, Article European Journal of Computational Mechanics ; Volume 24, Issue 3 , 2015 , Pages 79-106 ; 17797179 (ISSN) ; Vahab, M ; Ehsani, H ; Rafieerad, M ; Sharif University of Technology
Taylor and Francis Ltd
2015
Abstract
In the extended finite element method (FEM), the transition elements between the enriched and standard elements, which are generally referred as the blending, or partially enriched elements, are often crucial for a good performance of the local partition of unity enrichments. In these elements, the enrichment function cannot be reproduced exactly due to the lack of a partition of unity, and blending elements produce unwanted terms into the approximation that cannot be compensated by the standard final element part of the approximation. In this paper, some optimal X-FEM-type methods reported in literature are employed to study the performance of blending elements in large plastic deformation...
Modeling of moving boundaries in large plasticity deformations via an enriched arbitrary Lagrangian-Eulerian FE method
, Article Scientia Iranica ; Volume 17, Issue 2 A , 2010 , Pages 141-160 ; 10263098 (ISSN) ; Khoei, A. R ; Sharif University of Technology
2010
Abstract
In this paper, a new computational technique is presented for the modeling of moving boundaries in large plastic deformations based on an enriched arbitrary Lagrangian-Eulerian finite element method. An Arbitrary Lagrangian-Eulerian (ALE) technique is employed to capture the advantages of both Lagrangian and Eulerian methods and alleviate the drawbacks of mesh distortion in Lagrangian formulation. An enriched finite element method is implemented based on the extended FEM technique to capture the arbitrary interfaces independent of element boundaries. The process is accomplished by performing a splitting operator to separate the material (Lagrangian) phase from the convective (Eulerian)...
3D contact modelling of large plastic deformation in powder forming processes
, Article International Journal of Material Forming ; Volume 5, Issue 2 , 2012 , Pages 163-173 ; 19606206 (ISSN) ; Biabanaki, S. O. R ; Taheri Mousavi, S. M ; Vafa, A. R ; Parvaneh, S. M ; Sharif University of Technology
2012
Abstract
In this paper, the three-dimensional large frictional contact deformation of powder forming process is modeled using a node-to-surface contact algorithm based on the penalty and augmented-Lagrange approaches. The technique is applied by imposing the normal and tangential contact constraints and modifying the contact properties of frictional slip. The Coulomb friction law is employed to simulate the friction between the rigid punch and the work piece. It is shown that the augmented-Lagrange technique significantly improves imposing of the constraints on contact surfaces. In order to predict the non-uniform relative density and stress distributions during the large deformation of powder...
Fabrication of AZ31/Al2O3 nanocomposites by friction STIR processing
, Article Reviews on Advanced Materials Science ; Volume 28, Issue 1 , 2011 , Pages 85-89 ; 16065131 (ISSN) ; Kim, H. S ; Kokabi, A. H ; Abachi, P ; Shahraki, B. K ; Sharif University of Technology
2011
Abstract
The aim of this paper is to fabricate AZ31/Al2O3 nanocomposites by friction stir processing (FSP). Due to severe plastic deformation, dynamic recrystallization, and grain growth retardation by nanoparticles during the FSP processing, ultrafine grained microstructures with homogeneous distribution of the nanoparticles were produced. With increasing rotational speed, as a result of the increased plastic deformation and heat generation, increased grain size of the matrix, and simultaneously shattering effect of rotation cause a uniform nanoparticle distribution. By the large plastic deformation, texture of the matrix evolved and especially the (0002) basal plane was developed
Adiabatic shear banding in an Al-Mg-Si alloy processed by equal channel angular pressing
, Article Materials Science Forum, 2 August 2010 through 6 August 2010, Cairns, QLD ; Volume 654-656 , 2010 , Pages 1014-1017 ; 02555476 (ISSN) ; 0878492550 (ISBN) ; Taheri, A. K ; Yoo, J. H ; Joo, S. H ; Kim, H. S ; Sharif University of Technology
2010
Abstract
Equal channel angular pressing is an outstanding method for imposing large plastic deformation to metallic materials without any decreasing in cross section area of as processed samples. In this paper, the effect of working temperature, ram speed and the number of passes on the formation of adiabatic shear bands in Al6061 during equal channel angular pressing was investigated. Billets of the alloy were processed up to four passes via route BC from room temperature to 200°C with two ram speeds using a die that imparts an effective strain of ∼1.1 per pass. The results have demonstrated that the onset of the adiabatic shear banding in this alloy strongly depends on the ram speed: more...
Integration of physically based models into FE analysis: Homogeneity of copper sheets under large plastic deformations
, Article Computational Materials Science ; Volume 48, Issue 1 , 2010 , Pages 166-173 ; 09270256 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
2010
Abstract
In this paper, an integration approach consists of implementation of true internal state variables constitutive model to finite element (FE) analysis is presented. From the approach, the deformation homogeneity during severe plastic deformation of sheet (SPD) is investigated. Since there is not any constitutive model for large deformation that based on appropriated physical assumptions, here a new constitutive model is proposed that is entirely based on metallurgical mechanisms. Also, in order to achieve accurate results with low computation time, a new approach for integration of the constitutive model to FE analysis is presented. By coupling the constitutive model and FE analysis, the...
Cell-structure and flow stress investigation of largely strained non-heat-treatable Al-alloys using dislocation based model
, Article Materials Science and Engineering A ; Volume 739 , 2019 , Pages 167-172 ; 09215093 (ISSN) ; Kazeminezhad, M ; Sharif University of Technology
Elsevier Ltd
2019
Abstract
A severe plastic deformation is widely used to improve the mechanical properties of non-heat-treatable alloys. Thus, the investigation and modeling of microstructural evolutions of materials during large straining are of great importance. In this research, substructural evolutions of four different kinds of Al alloys namely Al-1Mn, Al-1Mg, Al-2.77Mg and Al-5Mg, have been studied using a dislocation based model and the mechanical properties of these alloys have been compared considering all microstructural parameters such as dislocation density, subgrain size, cell wall misorientation and the effect of alloying element. As a result, a simplified general equation has been expressed in order to...
Reliability analysis of notched plates under anisotropic damage based on uniaxial loading using continuum damage mechanics approach
, Article International Journal of Engineering, Transactions A: Basics ; Volume 34, Issue 1 , 2021 , Pages 253-262 ; 17281431 (ISSN) ; Gholami, P ; Sharif University of Technology
Materials and Energy Research Center
2021
Abstract
Extensive recent researches have been underway to model the fracture mechanics degradation based on continuum damage mechanics (CDM) technique. CDM theory is a powerful tool for solving problems such as large plastic deformations that the fracture mechanics is unable to solve. This model is derived by means of the thermodynamics internal variable theory and based on the experimental results on material properties. In this paper, the reliability of rectangular plates containing a central circular hole under static tensile load using the CDM approach for ductile fracture has been studied. To investigate the initiation and evolution of damages, anisotropic damage expressed by second order...
Optimum groove pressing die design to achieve desirable severely plastic deformed sheets
, Article Materials and Design ; Volume 31, Issue 1 , 2010 , Pages 94-103 ; 02641275 (ISSN) ; Hosseini, E ; Sharif University of Technology
2010
Abstract
In this paper, considering the problems of common finite element (FE) codes that consider simple constitutive equations, a developed FE code that considers a new constitutive model is used to simulate the behavior of copper sheets under severe plastic deformation (SPD). The new proposed constitutive model, that considers dislocation densities in cell interiors and cell walls of material as true internal state variables, can investigate all stages of flow stress evolution of material during large plastic deformations and also can explain the effects of strain rate magnitude on the mechanical response of material, during room temperature SPD. The proposed FE analysis is used to investigate the...