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A three-dimensional phenomenological constitutive model for porous shape memory alloys including plasticity effects
, Article Journal of Intelligent Material Systems and Structures ; Volume 27, Issue 5 , 2016 , Pages 608-624 ; 1045389X (ISSN) ; Arghavani, J ; Naghdabadi, R ; Auricchio, F ; Sharif University of Technology
SAGE Publications Ltd
2016
Abstract
Porous shape memory alloys are a class of very interesting materials exhibiting features typical of porous metals and of shape memory alloys. In contrast to dense shape memory alloys, considerable plastic strain accumulates in porous shape memory alloys even during phase transformation. Moreover, due to the microstructure of porous materials, phase transformation and plasticity phenomena are significantly pressure-dependent. In this article, we propose a three-dimensional phenomenological constitutive model for the thermomechanical behavior of porous shape memory alloys able to predict shape memory effect, pseudo-elastic behavior and plastic behavior under proportional as well as...
Thermomechanical Constitutive Modeling and Numerical Implementation of Porous Shape Memory Alloys Considering Irrecoverable Strain
, Ph.D. Dissertation Sharif University of Technology ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeed (Supervisor) ; Arghavani, Jamal (Co-Advisor)
Abstract
Porous shape memory alloys (SMAs) were fabricated by many researchers in the last decade and have been initially utilized as bone implants. Also, due to hysteresis in superelastic behavior, and the porous structure, porous SMAs can be used in energy absorbing applications. Such applications call for efficient constitutive modeling of porous SMAs. Moreover, porous SMAs with a wide range of porosity ratios and mechanical properties have been produced in the recent years; therefore, it is necessary to improve the available models and carefully study porous SMA behavior. Different approaches have been utilized for modeling porous SMA behavior. Most of the researchers used homogenization approach...
Air pressure dependence of natural-convection heat transfer
, Article World Congress on Engineering 2010, WCE 2010, London, 30 June 2010 through 2 July 2010 ; Volume 2 , 2010 , Pages 1444-1447 ; 9789881821072 (ISBN) ; Abardeh, R. H ; Sharif University of Technology
2010
Abstract
Heat transfer is one of the prevalent concepts with many usages in different fields of science, industry and so on. In different applications we need more or less to know about this phenomenon. Control of this phenomenon is too important in some cases and we should be aware how to control it. The importance of heat transfer rate and effect of various parameters on it, is a reason of performing this research. Because of changes of air pressure in different applications, we need to know how heat transfer affected by air pressure. In different places air pressure is higher or lower than atmospheric pressure and we can't use more of experimental equations (e.g. Morgan or Churchill-Chu for a...
A theory for coupled lithium insertion and viscoplastic flow in amorphous anode materials for Li-ion batteries
, Article Mechanics of Materials ; Volume 152 , 2021 ; 01676636 (ISSN) ; Arghavani, J ; Naghdabadi, R ; Brassart, L ; Sharif University of Technology
Elsevier B.V
2021
Abstract
Amorphous lithium metal alloys (LixM, with M=Si, Ge, Sn, …) are attractive anode materials for lithium-ion batteries owing to their high energy-storage capacity and safety characteristics. However, repeated insertion of lithium often leads to chemo-mechanical degradation of the alloy, which can severely reduce the battery capacity and cycle life. Better understanding of the chemo-mechanical response of lithium alloys is needed to guide the design of damage-resistant anode microstructures. In this work, we propose a constitutive theory that couples large, viscoplastic deformations to the insertion and extraction of lithium in amorphous electrode materials. The theory relies on the concept of...
A 3-D constitutive model for pressure-dependent phase transformation of porous shape memory alloys
, Article Journal of the Mechanical Behavior of Biomedical Materials ; Volume 42 , 2015 , Pages 292-310 ; 17516161 (ISSN) ; Arghavani, J ; Naghdabadi, R ; Sohrabpour, S ; Sharif University of Technology
Abstract
Porous shape memory alloys (SMAs) exhibit the interesting characteristics of porous metals together with shape memory effect and pseudo-elasticity of SMAs that make them appropriate for biomedical applications. In this paper, a 3-D phenomenological constitutive model for the pseudo-elastic behavior and shape memory effect of porous SMAs is developed within the framework of irreversible thermodynamics. Comparing to micromechanical and computational models, the proposed model is computationally cost effective and predicts the behavior of porous SMAs under proportional and non-proportional multiaxial loadings. Considering the pressure dependency of phase transformation in porous SMAs, proper...