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Ferdinando Auricchio - One of the best experts on this subject based on the ideXlab platform.
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A class of shape memory alloy constitutive models based on a new set of internal variables
2010Co-Authors: J. Arghavani, Ferdinando Auricchio, Saeed SohrabpourAbstract:In this paper we use the set of internal variables recently proposed by the authors to introduce a class of constitutive models for shape memory alloys. Such a class is based on the thermodynamics of irreversible processes with internal variables. A measure of Martensite Fraction and a measure of the preferred direction of variants are used as internal variables, describing thermo-elastic reversible martensitic phase transformation and stress-induced Martensite reorientation, respectively. We identify some constitutive models available in the literature and show that they belong to the introduced class of models. Moreover, we compare three constitutive models with two sets of experimental data available in the literature.
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A 1D rate-dependent viscous constitutive model for superelastic shape-memory alloys: formulation and comparison with experimental data
Smart Materials and Structures, 2007Co-Authors: Ferdinando Auricchio, Davide Fugazza, Reginald DesrochesAbstract:Experimental investigations on superelastic shape-memory alloys (SMAs) show a dependence of the stress–strain relationship on the loading–unloading rate. This feature is of particular importance when utilizing SMA materials for seismic applications, since the loading rate may affect the structural response. Motivated by this observation and by the fact that there exist relatively few studies on the material modelling of SMAs in earthquake engineering, the present work addresses a uniaxial constitutive equation able to describe the rate-dependent behaviour of superelastic SMAs. The formulation of the model is based on two scalar internal variables, the static Martensite Fraction and the dynamic Martensite Fraction, for which three different types of evolutionary equations in rate form are proposed. Moreover, the model takes into account the different elastic properties between austenite and Martensite. Finally, after discussing two possible approaches for the solution of the corresponding time-discrete framework, the ability of the model to simulate experimental data obtained from uniaxial tests performed on SMA wires and bars at frequency levels of excitation typical of earthquake engineering is assessed. (Some figures in this article are in colour only in the electronic version)
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Numerical and Experimental Evaluation of the Damping Properties of Shape-Memory Alloys
Journal of Engineering Materials and Technology, 2006Co-Authors: Ferdinando Auricchio, Davide Fugazza, Reginald DesrochesAbstract:This paper presents and compares two different uniaxial constitutive models for superelastic shape-memory alloys (SMAs), suitable to study the dependence of the stress-strain relationship on the loading-unloading rate. The first model is based on the inclusion of a direct viscous term in the evolutionary equation for the Martensite Fraction and it shows how the material response is bounded between two distinct rate-independent models. The second model is based on a rate-independent evolutionary equation for the Martensite Fraction coupled with a thermal balance equation. Hence, it considers mechanical dissipation as well as latent heat and includes the temperature as a primary independent variable, which is responsible of the dynamic effects. The ability of both models to reproduce the observed reduction of damping properties through the modification of the hysteresis size is discussed by means of several numerical simulations. Finally, the capacity of the constitutive equations to simulate experimental data from uniaxial tests performed on SMA wires and bars of different size and chemical composition is shown.
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Three-dimensional modeling of shape-memory materials
Le Journal de Physique IV, 2001Co-Authors: Ferdinando AuricchioAbstract:The paper describes a model able to reproduce through a phenomenologic al approach some of the main macroscopic features of shape-memory materials for three-dimensional states of stress. In particular, we consider in details the case of superelastic response, giving insights on how extending the model to include the shape-memory effect. The model is framed on a large deformation context and it based on the introduction of a scalar internal variable - the single-variant Martensite Fraction - and on a tensorial internal variable - measuring the single-variant Martensite orientation.
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A uniaxial model for shape-memory alloys
International Journal of Solids and Structures, 1997Co-Authors: Ferdinando Auricchio, Jacob LublinerAbstract:Abstract We present a uniaxial model for shape-memory alloys, cast within the generalized plasticity framework, previously developed. The model is based on two internal variables (the single-variant Martensite Fraction and the multiple-variant Martensite Fraction), for which evolution equations in rate form are proposed. The model reproduces the shape-memory effect and the superelastic behavior; moreover, for loading-unloading cycles, without completion of the phase transition, it presents a cyclic response with internal loops.
Katsuyuki Kinoshita - One of the best experts on this subject based on the ideXlab platform.
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Evaluation of magnetic properties in ferromagnetic Martensite particle using type 304 stainless steel wire
AIP Advances, 2020Co-Authors: Katsuyuki KinoshitaAbstract:In this study, the magnetic properties of a single Martensite particle were investigated using type 304 stainless wire, which can reduce the number of crystal grains per unit area. First, the magnetization curve of wire specimens with different Martensite Fractions was measured by a SQUID magnetic flux meter. Then, the coercivity and susceptibility parameters were evaluated from the magnetization curve and factors contributing to these parameters were discussed. It was found that the coercivity values along the long and short axes of wire specimens with a diameter of 0.4 mm increased and subsequently decreased with an increase in the Martensite Fraction. Further, the susceptibility values of the same specimen along the long axis increased and along the short axis decreased with increasing Martensite Fractions. The results indicate that the coercivity and susceptibility of a Martensite particle are affected by the size of variant clusters and the shape anisotropy of the Martensite particle.In this study, the magnetic properties of a single Martensite particle were investigated using type 304 stainless wire, which can reduce the number of crystal grains per unit area. First, the magnetization curve of wire specimens with different Martensite Fractions was measured by a SQUID magnetic flux meter. Then, the coercivity and susceptibility parameters were evaluated from the magnetization curve and factors contributing to these parameters were discussed. It was found that the coercivity values along the long and short axes of wire specimens with a diameter of 0.4 mm increased and subsequently decreased with an increase in the Martensite Fraction. Further, the susceptibility values of the same specimen along the long axis increased and along the short axis decreased with increasing Martensite Fractions. The results indicate that the coercivity and susceptibility of a Martensite particle are affected by the size of variant clusters and the shape anisotropy of the Martensite particle.
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Influence of tensile stress on permeability properties of type 304 stainless steel
Journal of Applied Physics, 2015Co-Authors: Katsuyuki KinoshitaAbstract:The permeability properties of type SUS304 stainless steel (SUS304 steel) were evaluated under different values of tensile stress using the electromagnetic impedance method. The impedance–magnetic-field curve of SUS304 steel, which corresponds to the permeability–magnetic field-curve, was measured under tensile stresses of 0, 70, and 140 MPa for specimens subjected to prestrains of 5% to 40% to change the Martensite Fraction. The impedance curves were measured in the length (tensile) direction and the width direction. The results showed that the tensile direction was the magnetic hard axis of the Martensite phase in SUS304 steel. The applied stress sensitivity of the permeability in SUS304 steel was affected by the volume Fraction, residual stress, stress distribution according to the orientation angle of the Martensite phase, and their interactions.
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variation of the magnetic properties of the Martensite phase of sus304 steel due to tensile deformation
International Journal of Applied Electromagnetics and Mechanics, 2014Co-Authors: Katsuyuki Kinoshita, Ryo Nakazaki, Eiji MatsumotoAbstract:In order to be able to develop a deterioration sensor based on the inherent magnetic phase in type 304 stainless steel (SUS304 steel), the relationships between the magnetic properties of SUS304 steel and the Martensite structure induced in it by tensile deformation were investigated using the electromagnetic impedance (EMI) method, optical microscopy, and the equivalent inclusion method. The results showed that the Martensite Fraction and internal stress had the greatest effect on the magnetic properties of SUS304 steel in the low tensile strain range. On the other hand, in the high tensile strain region, the changes in the shape and orientation of the Martensite particles owing to tensile deformation had the most significant effect on the magnetic properties of SUS304 steel.
L. C. Brinson - One of the best experts on this subject based on the ideXlab platform.
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Phase diagram based description of the hysteresis behavior of shape memory alloys
Acta Materialia, 1998Co-Authors: A. Bekker, L. C. BrinsonAbstract:Abstract In this paper, we develop a consistent mathematical description of Martensite Fraction evolution during athermal thermoelastic phase transformation in a shape memory alloy (SMA) induced by a general thermomechanical loading. The global kinetic law is based on an experimentally defined stress–temperature phase diagram, transformation functions for a one-dimensional SMA body and a novel vector hysteresis model. The global kinetic law provides the phase Fraction history given a loading path on the stress–temperature phase diagram and an initial value of Martensite Fraction. The phase transformation is considered to occur only within transformation strips on the phase diagram and only on loading path segments oriented in the transformation direction. The developed procedure can be used to model a range of different SMA transformation behaviors depending on the choice of transformation functions and local kinetic law algorithms. The phase Fraction evolution is examined for a number of characteristic examples, including cyclic loading resulting in oscillatory transformation paths, and internal loops of partial transformation with associated attractor loops. Differences between the various local kinetic law algorithms used in the overall framework are highlighted. The simulation results using a cosine transformation function are found to be in excellent agreement with experimental data.
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Temperature-induced phase transformation in a shape memory alloy: Phase diagram based kinetics approach
Journal of the Mechanics and Physics of Solids, 1997Co-Authors: A. Bekker, L. C. BrinsonAbstract:In this article we develop a general framework to model the one dimensional thermomechanical behavior of shape memory alloys (SMAs) based on phase diagram kinetics and a phenomenological constitutive law with Martensite Fraction as an internal variable. As part of this framework, we construct a consistent mathematical description for Martensite Fraction evolution to be used in conjunction with an experimentally defined phase diagram; the kinetics formalism is illustrated with examples of isostress and isothermal cycling. As an application, we consider the thermo-induced Martensite transformation of a 1D prestressed SMA polycrystalline body which proceeds by migration of the austenite-Martensite two-phase zone from the cooled boundary, converting the SMA body from an austenite (A) to a detwinned Martensite (M) state. The mathematical model for the two-phase zone migration is based on the nonstationary equation of energy balance and the quasistationary approximation for the linear momentum equation and utilizes a quasistatic kinetic law, a macroscale constitutive law and an incompressibility constraint. To close the formulated system of equations, the internal energy of an A/M mixture in the two-phase zone is heuristically derived. The mixed initial-boundary value problem is then solved numerically and compared to analytical results for a simplified model. The results stress the significance of the stress dependency in the kinetic law and the transformation heat to the progress of transformation.
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One Dimensional Constitutive Behavior of Shape Memory Alloys.
1993Co-Authors: L. C. BrinsonAbstract:A one-dimensional constitutive model for the thermomechanical behavior of shape memory alloys is developed based on previous work by Liang and Tanaka. An internal variable approach is used to derive a comprehensive constitutive law for shape memory alloy materials from first principles without the assumption of constant material functions. This constitutive law is of such a form that it is well suited to further practical engineering applications and calculations. A separation of the Martensite Fraction internal variable into temperature-induced and stress-induced parts is presented and justified which then allows the derived constitutive law to accurately represent both the pseudoelastic and shape memory effects at all temperatures. Several numerical examples are given which illustrate the ability of the constitutive law to capture the unique thermomechanical behavior of shape memory alloys due to their internal phase transformations with stress and temperature.
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Constitutive Behavior of Shape Memory Alloys: One dimensional thermomechanical derivation with non-constant material functions and redefined Martensite internal variable.
1992Co-Authors: L. C. BrinsonAbstract:A one-dimensional constitutive model for the thermomechanical behavior of shape memory alloys is developed based on previous work by Liang and Tanaka. An internal variable approach is used to derive a comprehensive constitutive law for shape memory alloy materials from first principles without the assumption of constant material functions. This constitutive law is of such a form that it is well suited to further practical engineering applications and calculations. A separation of the Martensite Fraction internal variable into temperature-induced and stress-induced parts is presented and justified which then allows the derived constitutive law to accurately represent both the pseudoelastic and shape memory effects at all temperatures. Several numerical examples are given which illustrate the ability of the constitutive law to capture the unique thermomechanical behavior of shape memory alloys due to their internal phase transformations with stress and temperature.
Denis Favier - One of the best experts on this subject based on the ideXlab platform.
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specific forward reverse latent heat and Martensite Fraction measurement during superelastic deformation of nanostructured niti wires
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2020Co-Authors: Henrique Martinni Ramos De Oliveira, Hervé Louche, Estephanie Nobre Dantas Grassi, Denis FavierAbstract:This study analyses the thermomechanical tensile behaviour of a cold drawn Ti-50.9at.%Ni wire submitted to heat treatment at 598 K for 30 min, which is below the recrystallization temperature (623 K). Such low temperature heat treatment induces a superelastic loop without a stress "plateau". However, the absence or weakness of peaks on its differential scanning calorimetry prevents the determination of specific latent heat. This is a common effect of nanostructured materials such as superelastic wires. A method using strain and temperature field measurements was developed and used to determine thermal power and thermal energy during superelastic tensile tests through a heat balance. From these results and using a thermodynamic approach, forward and reverse specific latent heat and the Martensite Fraction are estimated as a function of strain and stress.
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Specific forward/reverse latent heat and Martensite Fraction measurement during superelastic deformation of nanostructured NiTi wires
Materials Science and Engineering: A, 2020Co-Authors: Henrique Ramos De Oliveira, Hervé Louche, Estephanie Nobre Dantas Grassi, Denis FavierAbstract:This study analyses the thermomechanical tensile behaviour of a cold drawn Ti-50.9at.%Ni wire submitted to heat treatment at 598 K for 30 min, which is below the recrystallization temperature (623 K). Such low temperature heat treatment induces a superelastic loop without a stress "plateau". However, the absence or weakness of peaks on its differential scanning calorimetry prevents the determination of specific latent heat. This is a common effect of nanostructured materials such as superelastic wires. A method using strain and temperature field measurements was developed and used to determine thermal power and thermal energy during superelastic tensile tests through a heat balance. From these results and using a thermodynamic approach, forward and reverse specific latent heat and the Martensite Fraction are estimated as a function of strain and stress.
Emin Semih Perdahcioglu - One of the best experts on this subject based on the ideXlab platform.
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strain direction dependency of martensitic transformation in austenitic stainless steels the effect of gamma texture
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2013Co-Authors: P Hilkhuijsen, Emin Semih Perdahcioglu, H J M Geijselaers, T C Bor, Van Den A H Boogaard, Remko AkkermanAbstract:Uniaxial tensile tests on both a non-textured and a highly textured, fully austenitic stainless steel were performed in both the rolling and the transverse directions. Both materials show mechanically induced phase transformation from the austenitic FCC to the martensitic BCC phase. Differences in overall transformation behavior are observed between the two steels. No direction-dependent transformation behavior is present during deformation of the nontextured steel. However, when a strong texture is present, differences in transformation behavior during deformation in different directions can be observed clearly. The ‘stress induced transformation’ theory, in combination with the austenite texture measured before deformation, is used to explain and model the transformation behavior when straining in different directions. The theoretical results of the stress-induced transformation theory compare well with the measured austenitic textures after deformation and the recorded stress vs Martensite Fraction curves.
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influence of stress state and strain path on deformation induced martensitic transformations
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Emin Semih Perdahcioglu, H J M Geijselaers, J. HuetinkAbstract:The mechanically induced transformation behavior of 12Crsingle bond9Nisingle bond 4Mo (ASTM A 564) austenitic stainless steel is investigated in different stress states. This phenomenon is studied experimentally on a plane-stress biaxial test facility. The facility can load a sheet specimen simultaneously in shear and tension which enables us to investigate the effect of stress state on transformation kinetics. The Martensite Fraction is monitored via a magnetic sensor while the strain is measured using a camera and a dot-tracking software.