scholarly journals Constitutive Modelling and Numerical Implementation of SMA Material with Internal Loops

2018 ◽  
Vol 64 (4) ◽  
pp. 211-232 ◽  
Author(s):  
A. Zbiciak ◽  
K. Wasilewski
Keyword(s):  
Shape Memory ◽  
Three Dimensional ◽  
Martensite Phase ◽  
Constitutive Modelling ◽  
Historical Buildings ◽  
Dynamic Simulations ◽  
Dynamic Excitation ◽  
Dimensional Finite Element ◽  
Internal Loops ◽  
Three Dimensional Finite Element

AbstractThe article presents a constitutive model for Shape Memory Alloys (SMA) along with result of dynamic simulations of SMA model. The applications of devices incorporating SMA in civil engineering focus mostly on mitigation of the seismic hazard effects in new-build and historical buildings or improvement of fatigue resilience. The unique properties of SMA, such as shape memory effect and superelasticity give promising results for such applications. The presented model includes additional phenomenon of SMA – internal loops. The paper shows the method of formulation of physical relations of SMA based on special rheological structure, which includes modified Kepes’s model. This rheological element, introduced as dual-phase plasticity body, is given in the context of martensite phase transformation. One of the advantages of such an approach is a possibility of formulation of constitutive relationships as a set of explicit differential equations. The application of the model is demonstrated on example of dynamic simulations of three dimensional finite element subjected to dynamic excitation.

Gear Meshing Noise of the Closed Gearbox

2014 ◽  
Vol 607 ◽  
pp. 527-530
Author(s):  
Fu Zhong Chen ◽  
Yong Jun Shi ◽  
Lei Yan Yu
Keyword(s):  
Finite Element ◽  
Boundary Element Method ◽  
Boundary Element ◽  
Three Dimensional ◽  
Power Measurement ◽  
Sound Power ◽  
Gear Mesh ◽  
Dynamic Excitation ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

The dynamic excitation and the noise of meshing gears were analyzed quantitatively using the three-dimensional finite element contact analysis and the boundary element method. The distribution and variation roles of the gear mesh noise were obtained. The simulation result was verified by sound power measurement. The main excitation was determined additionally. It provides the theory basis for the control of the gearbox noise.

Analytical model for a superelastic Timoshenko shape memory alloy beam subjected to a loading–unloading cycle

2018 ◽  
Vol 29 (20) ◽  
pp. 3902-3922 ◽  
Author(s):  
Nguyen Van Viet ◽  
Wael Zaki ◽  
Rehan Umer
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Analytical Model ◽  
Solid Phase ◽  
Three Dimensional ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

We propose a new analytical model for a superelastic shape memory alloy prismatic cantilever beam subjected to a concentrated force at the tip. The force is gradually increased and then removed and the corresponding distribution of phase transformation fields in the beam is determined, analytically, in both the transverse and longitudinal directions. Analytical moment–curvature and shear force–shear strain relations are also derived during loading and unloading of the beam. The proposed model is validated against an exact numerical beam model as well as a three-dimensional finite element analysis model for the same beam, with very good agreement in each case. Moreover, an experiment is proposed and carried out to characterize the load–deflection response of a shape memory alloy beam under the same boundary conditions as those considered in deriving the model. The obtained response is in good agreement with the analytical model as well as three-dimensional finite element analysis simulations. The analytical method provides a direct mathematical way for describing the material and structural properties of the beam and the distribution of the different solid phase regions as they change under the influence of an applied load and allows the determination of details such as the boundaries of solid phase regions immediately and accurately using equations. The same would require postprocessing at possibly significant computational cost and personal effort if finite element analysis or similar numerical methods are used.

Bending analysis of soft core sandwich plates with embedded shape memory alloy wires using three-dimensional finite element method

2012 ◽  
Vol 226 (3) ◽  
pp. 186-202 ◽  
Author(s):  
Mohammad M Kheirikhah ◽  
Mahdi Khadem ◽  
Peyman Farahpour
Keyword(s):  
Finite Element Method ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Sandwich Plate ◽  
Three Dimensional ◽  
Shear Stresses ◽  
Sandwich Plates ◽  
Dimensional Finite Element ◽  
Transverse Shear Stresses ◽  
Three Dimensional Finite Element

In this article, bending behavior of the sandwich plates with embedded shape memory alloy wires in their face sheets is studied. Three-dimensional finite element method is used for constructing and analyzing the sandwich plates with flexible core and two stiff face sheets. Some important points such as continuity conditions of the displacements, satisfaction of inter-laminar transverse shear stresses, conditions of zero transverse shear stresses on the upper and lower surfaces and in-plane and transverse flexibility of the soft core are considered for the accurate modeling of the sandwich plate. Solutions for bending analysis of shape memory alloy wire-reinforced sandwich plates under various transverse loads are presented and the effects of plate dimensions, shape memory alloy wires diameter, boundary conditions and shape memory alloy wires embedding positions are studied. Comparison of the present results in special case with those of the three-dimensional theory of elasticity and some plate theories confirms the accuracy of the proposed model. According to the obtained numerical results, the local behavior of the sandwich plate in bending against various loading conditions was significantly improved by employing the shape memory alloy wires in the face sheets.

scholarly journals The effect of along-strike variation in dip on rupture propagation on strike-slip faults

Geosphere ◽  
2021 ◽  
Author(s):  
Julian C. Lozos
Keyword(s):  
Initial Stress ◽  
Large Body ◽  
Three Dimensional ◽  
Strike Slip ◽  
Dynamic Simulations ◽  
Motion Patterns ◽  
Geometrical Complexity ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element

Strike-slip faults can be nonplanar in both their strike and dip dimensions. While a large body of work has investigated the effects of changes in strike on earthquake rupture and arrest, no previous studies have investigated the role of along-strike variations in dip on strike-slip ruptures. Here, I use the three-dimensional finite-element method to conduct dynamic simulations of ruptures on strike-slip faults with linear surface traces and changes in dip along strike. I experiment with the amount of dip change as well as the abruptness of that change under a variety of initial stress conditions. In all of my initial stress cases, I find that a change in dip along strike can cause rupture to stop, and that larger dip changes over shorter distances are more likely to do so. This is largely due to the change in strike at depth that inherently comes from changing the dip; the majority of these behaviors are a result of the rupture front being forced to change direction mid-rupture. While some dip-slip movement does occur on the nonvertical parts of the model fault, it does not have a significant effect on rupture extent. However, linear-surface-trace, nonvertical-dip faults do produce different surface slip, stress, and ground motion patterns compared to corresponding nonlinear-strike, vertical-dip faults. Together, my results show that changes in dip along strike-slip faults do considerably impact the rupture process, suggesting that this type of geometrical complexity should be considered in rupture forecasts and hazard assessments.

Modeling of a Shape Memory Alloy Circular Bar Under Combined Axial-Torsional Loading

2012 ◽  
Author(s):  
Masood Taheri Andani ◽  
Amin Alipour ◽  
Ahmadreza Eshghinejad ◽  
Mohammad Elahinia
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Constitutive Relations ◽  
Three Dimensional ◽  
Torsional Loading ◽  
Equilibrium Equations ◽  
Dimensional Finite Element ◽  
Loading And Unloading ◽  
Circular Bar ◽  
Three Dimensional Finite Element

In this paper, a semi-analytical analysis of the pseudoelastic response of shape memory alloy rods and tubes subjected to combined axial and torsional loading is proposed. A three-dimensional phenomenological SMA constitutive model is simplified to obtain the corresponding two-dimensional constitutive relations. The rod is partitioned into a finite number of narrow annular regions and the equilibrium equations are found in each annular region for both loading and unloading paths. Several numerical examples are presented to demonstrate the efficiency of the proposed method, and the results are compared with three-dimensional finite element simulations.

Bending Analysis of Textured Polycrystalline Shape Memory Alloy Beams

2012 ◽  
Author(s):  
Reza Mirzaeifar ◽  
Reginald DesRoches ◽  
Arash Yavari ◽  
Ken Gall
Keyword(s):  
Shape Memory Alloy ◽  
Shape Memory ◽  
Crystallographic Texture ◽  
Three Dimensional ◽  
Transformation Strain ◽  
Element Model ◽  
Crystal Orientations ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Bending Response

In this paper a micro-mechanical model that incorporates single crystal constitutive relationships is used for studying the pseudoelastic response of polycrystalline shape memory alloy beams subjected to bending. In the micro-mechanical framework, the stress-free transformation strains of all the 24 correspondence variant pairs (CVPs) obtained from the crystallographic data of NiTi are used, and the overall transformation strain is obtained by defining a set of martensitic volume fractions corresponding to active CVPs during a phase transformation. A three-dimensional finite element model is used and a polycrystalline beam is modeled based on Voronoi tessellations. The effect of crystallographic texture and the tension-compression asymmetry on the bending response of superelastic beams is studied. The results of texture measurements are used to assign appropriate crystal orientations to the grains in the model. By considering various combinations of crystal orientations, the effect of preferred crystallographic texture on the bending response is studied. The size effect is also studied by considering two polycrystal structures with different number of grains.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

Tire Modeling by Finite Elements

1992 ◽  
Vol 20 (1) ◽  
pp. 33-56 ◽  
Author(s):  
L. O. Faria ◽  
J. T. Oden ◽  
B. Yavari ◽  
W. W. Tworzydlo ◽  
J. M. Bass ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Rolling Contact ◽  
Test Problems ◽  
State Behavior ◽  
Normal Contact ◽  
New Developments ◽  
Applied Torque ◽  
Dimensional Finite Element ◽  
Tire Modeling ◽  
Three Dimensional Finite Element

Abstract Recent advances in the development of a general three-dimensional finite element methodology for modeling large deformation steady state behavior of tire structures is presented. The new developments outlined here include the extension of the material modeling capabilities to include viscoelastic materials and a generalization of the formulation of the rolling contact problem to include special nonlinear constraints. These constraints include normal contact load, applied torque, and constant pressure-volume. Several new test problems and examples of tire analysis are presented.

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