Modeling of the Mechanical Behavior of Shape Memory Alloys under Cyclic Loading Considering Detwinning-induced Plasticity and Transformation-induced Plasticity

, Ph.D. Dissertation Sharif University of Technology Ebrahimi Estahbanati, Parvin (Author) ; Naghdabadi, Reza (Supervisor) ; Sohrabpour, Saeid (Supervisor) ; Arghavani Hadi, Jamal (Co-Supervisor) ; McGarry, Patrick (Co-Supervisor)

Abstract

The main goal of the current study is to incorporate the effect of microstructural deformation mechanisms, such as detwinning-induced plasticity, into constitutive and computational modeling of NiTi shape memory alloys. Therefore, based on thermodynamic considerations a new inelastic mechanism, detwinning-induced plasticity (DIP), is proposed for modelling the response of NiTi SMAs to cyclic loading. DIP is incorporated into a constitutive framework that also includes other well-established inelastic mechanisms of phase transformation, transformation-induced plasticity, residual martensite and detwinning. The model is constructed at the single crystal scale using the framework of...

On the effect of detwinning-induced plasticity in compressive cyclic loading of NiTi shape memory alloys

, Article Mechanics of Materials ; Volume 148 , 2020 Ebrahimi, P ; Arghavani, J ; Naghdabadi, R ; McGarry, J. P ; Sharif University of Technology

Elsevier B.V 2020

Abstract

A new inelastic mechanism, detwinning-induced plasticity (DIP), is proposed to model the response of NiTi SMAs to cyclic loading, based on thermodynamic considerations. DIP is incorporated into a constitutive framework for NiTi SMA. The constitutive framework also includes well-established inelastic mechanisms of phase transformation, transformation-induced plasticity, residual martensite, and detwinning. The model is constructed at the single crystal scale using the framework of thermodynamics and a crystal plasticity formulation. An explicit scale-transition rule is adopted for the simulation of polycrystalline materials, allowing direct comparison of the model predictions with published...

Advances in heuristic signal processing and applications

, Book ; Chatterjee, Amitava ; Nobahari, Hadi ; Siarry, Patrick

Springer 2013

Abstract

There have been significant developments in the design and application of algorithms for both one-dimensional signal processing and multidimensional signal processing, namely image and video processing, with the recent focus changing from a step-by-step procedure of designing the algorithm first and following up with in-depth analysis and performance improvement to instead applying heuristic-based methods to solve signal-processing problems. In this book the contributing authors demonstrate both general-purpose algorithms and those aimed at solving specialized application problems, with a special emphasis on heuristic iterative optimization methods employing modern evolutionary and swarm...

739 observed NEAs and new 2-4 m survey statistics within the EURONEAR network

, Article Planetary and Space Science ; Volume 85 , September , 2013 , Pages 299-311 ; 00320633 (ISSN) Vaduvescu, O ; Birlan, M ; Tudorica, A ; Popescu, M ; Colas, F ; Asher, D. J ; Sonka, A ; Suciu, O ; Lacatus, D ; Paraschiv, A ; Badescu, T ; Tercu, O ; Dumitriu, A ; Chirila, A ; Stecklum, B ; Licandro, J ; Nedelcu, A ; Turcu, E ; Vachier, F ; Beauvalet, L ; Taris, F ; Bouquillon, L ; Pozo Nunez, F ; Colque Saavedra, J. P ; Unda-Sanzana, E ; Karami, M ; Khosroshahi, H. G ; Toma, R ; Ledo, H ; Tyndall, A ; Patrick, L ; Föhring, D ; Muelheims, D ; Enzian, G ; Klaes, D ; Lenz, D ; Mahlberg, P ; Ordenes, Y ; Sendlinger, K ; Sharif University of Technology

2013

Abstract

We report follow-up observations of 477 program Near-Earth Asteroids (NEAs) using nine telescopes of the EURONEAR network having apertures between 0.3 and 4.2 m. Adding these NEAs to our previous results we now count 739 program NEAs followed-up by the EURONEAR network since 2006. The targets were selected using EURONEAR planning tools focusing on high priority objects. Analyzing the resulting orbital improvements suggests astrometric follow-up is most important days to weeks after discovery, with recovery at a new opposition also valuable. Additionally we observed 40 survey fields spanning three nights covering 11 square degrees near opposition, using the Wide Field Camera on the 2.5 m...