Exact Solution for Bending of Shape Memory Alloy Superelastic Beams

2011 ◽  
Author(s):  
Ahmadreza Eshghinejad ◽  
Mohammad Elahinia
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
Finite Element ◽  
Numerical Methods ◽  
Shape Memory ◽  
Cross Section ◽  
Analytical Approach ◽  
Thermomechanical Behavior ◽  
Linear Distribution ◽  
Mode Of Application

Bending is a common mode of application and operation of shape memory alloys (SMA). So far the coupled thermomechanical behavior of these alloys have been modeled with numerical methods such as finite element. The issue in developing exact solutions for a SMA beam in bending is because of the distributed and hysteric stress-strain profile. In this paper an analytical approach is developed to find the exact solution for the displacement due to the applied force on the SMA superelastic beam. The approach is based on the assumption of linear distribution of strain along the height of a cross section in the beam. The solution is validated by experimental data and the results of the solution for a superelastic beams for different cases are illustrated.

scholarly journals Evaluation of Pile’s Buckling Under Axial Load by B-Spline Method and Comparison With Finite Element Method and Exact Solution

2018 ◽  
Vol 8 (2) ◽  
pp. 29-34
Author(s):  
A. Moghaddam ◽  
A. Nayeri ◽  
S.M. Mirhosseini
Keyword(s):  
Finite Element Method ◽  
Exact Solution ◽  
Finite Element ◽  
Numerical Methods ◽  
High Volume ◽  
Spline Method ◽  
B Spline ◽  
Volume Calculations ◽  
Reaction Coefficient ◽  
Element Method

Abstract Although various analytical and numerical methods have been proposed by researchers to solve equations, but use of numerical tools with low volume calculations and high accuracy instead of other numerical methods with high volume calculations is inevitable in the analysis of engineering equations. In this paper, B-Spline spectral method was used to study buckling equations of the piles. Results were compared with the calculated amounts of the exact solution and finite element method. Uniform horizontal reaction coefficient has been used in most of proposed methods for analyzing buckling of the pile on elastic base. In reality, soil horizontal reaction coefficient is nonlinear along the pile. So, in this research by using B-Spline method, buckling equation of the pile with nonlinear horizontal reaction coefficient of the soil was investigated. It is worth mentioning that B-Spline method had not been used for buckling of the pile.

scholarly journals Application of classical numerical methods in the calculation of solidification modes of a continuous ingot

2020 ◽  
pp. 41-47
Author(s):  
V. I. Timoshpolsky ◽  
E. I. Marukovich ◽  
I. A. Trusova
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Numerical Methods ◽  
Continuous Casting ◽  
Computational Analysis ◽  
The Finite Element Method ◽  
Casting Technology ◽  
Continuous Ingot ◽  
Continuously Cast

This paper presents approaches to the computational analysis of solidification and cooling processes of continuously cast billets in order to improve and develop technological modes in the conditions of modern continuous casting machines using FEM.The application of modern numerical methods for solidification and cooling of workpieces on continuous casting machines is considered. The use of the finite element method is justified when using computational and experimental data for the development and improvement of casting technology.

Three-Dimensional Numerical Simulation of Thermomechanical Constitutive Model for Shape Memory Polymers With Application to Morphing Wing Skin

2013 ◽  
Author(s):  
Olaniyi A. Balogun ◽  
Changki Mo ◽  
A. K. Mazher ◽  
John C. Brigham
Keyword(s):  
Numerical Simulation ◽  
Finite Element ◽  
Constitutive Model ◽  
Shape Memory ◽  
Three Dimensional ◽  
Shape Memory Polymers ◽  
Thermomechanical Behavior ◽  
One Dimensional ◽  
Simulation Results ◽  
Wing Skin

This paper presents three-dimensional numerical simulation of thermomechanical constitutive model for shape memory polymers. Shape memory polymers (SMPs) are a class of smart materials with high potential for application to automotive, aerostructures, and medical devices, which can benefit from its intrinsic shape changing properties. In particular, looking at its application to aerospace substructure such as morphing wings, thermomechanical behavior of the SMPs needs to be well established and predicted. In order to predict the thermomechanical behavior of SMPs structures, a one-dimensional rheological thermomechanical constitutive model was adopted and a numerical simulation of this model was developed using a commercial finite element analysis package ABAQUS. The particular one-dimensional model was selected due to its potential to represent the key material behaviors of SMP with a relatively low number of required material constants, which is practical for engineering industrial applications. The model was expanded to a three-dimensional isotropic model and then incorporated into the finite element method by means of an ABAQUS user-defined subroutine (UMAT). The methods of three-dimensional expansion and numerical implementation are presented in this work. A time evolution of the analysis was conducted by making use of the backward difference method, which was applied to all quantities within the model including the material properties. A comparison of the numerical simulation results was carried out with the available experimental data. Numerical simulation results clearly exhibit the thermomechanical properties of the material, which include shape fixity, shape recovery, and recovery stress. Finally, a preliminary set of predictions for an unmanned aerial vehicle (UAV) morphing wing skin are also presented.

scholarly journals Mechanical Behavior of Steel Pipe Bends: An Overview

2016 ◽  
Vol 138 (4) ◽  
Author(s):  
Spyros A. Karamanos
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Mechanical Behavior ◽  
Cross Section ◽  
Steel Pipe ◽  
Buried Pipelines ◽  
Cross Sectional ◽  
Out Of Plane ◽  
Bending Capacity ◽  
Bending Loading

An overview of the mechanical behavior of steel pipe (elbows) is offered, based on previously reported analytical solutions, numerical results, and experimental data. The behavior of pipe bends is characterized by significant deformations and stresses, quite higher than the ones developed in straight pipes with the same cross section. Under bending loading (in-plane and out-of-plane), the main feature of the response is cross-sectional ovalization, which influences bending capacity and is affected by the level of internal pressure. Bends subjected to cyclic in-plane bending exhibit fatigue damage, leading to base metal cracking at the elbow flank. Using advanced finite-element tools, the response of pipe elbows in buried pipelines subjected to ground-induced actions is also addressed, with emphasis on soil–pipeline interaction. Finally, the efficiency of special-purpose finite elements for modeling pipes and elbows is briefly discussed.

Finite Element Analysis on the Behavior of Laminated Composite Shells With Embedded Shape Memory Alloy Wires

2007 ◽  
Author(s):  
H. K. Cho
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Shape Memory Alloy ◽  
Shape Memory ◽  
Laminated Composite ◽  
Thermomechanical Behavior ◽  
Nonlinear Finite Element ◽  
Constitutive Law ◽  
Composite Shells ◽  
Laminated Composite Shells

Motivated by needs such as those in the aerospace industry, this paper demonstrates the thermomechanical characteristics of static and dynamic (frequency) behaviors of laminated composite shells with embedded shape memory alloy (SMA) wire subjected to temperature environments. Numerical analysis for SMA fiber reinforced composite laminates is performed by synergizing finite element method with Brison’s model [1,2] of SMA constitutive law. A nonlinear finite element procedure with respect to shape memory alloy hybrid composite (SMAHC) shell has been developed which incorporates a thermodynamically derived constitutive law for SMA behavior. Present illustrative applications involve rectangular laminated panels clamped along one side, although the method is applicable to more complicated laminates, geometries and boundary conditions. Panel geometry is discretized into specially-developed 3D degenerated eight-node laminated composite shell elements. General shell theory, involving incremental nonlinear finite element equilibrium that includes large deformations with Green-Lagrange strains, is employed. Several test cases which depend on volume fraction of SMA, temperature and ply angles are presented to illustrate the thermomechanical behavior of SMAHC. The results of numerical analysis show the ability of the suggested procedure to compute the thermomechanical behavior of SMAHC due to SMA’s internal phase transformations with stress and temperature.

On Power Flow Suppression in Straight Elastic Pipes by Use of Equally Spaced Eccentric Inertial Attachments

2012 ◽  
Vol 134 (4) ◽  
Author(s):  
Sergey Sorokin ◽  
Ole Holst-Jensen
Keyword(s):  
Experimental Data ◽  
Exact Solution ◽  
Cross Section ◽  
Power Flow ◽  
Floquet Theory ◽  
Boundary Integral Equations ◽  
Flow Analysis ◽  
Elastic Beam ◽  
Boundary Integral ◽  
Parametric Studies

The paper addresses the power flow suppression in an elastic beam of the tubular cross section (a pipe) at relatively low excitation frequencies by deploying a small number of equally spaced inertial attachments. The methodology of boundary integral equations is used to obtain an exact solution of the problem in vibrations of this structure. The power flow analysis in a pipe with and without equally spaced eccentric inertial attachments is performed and the effect of suppression of the energy transmission is demonstrated theoretically. These results are put in the context of predictions from the classical Floquet theory for an infinitely long periodic structure. Parametric studies are performed to explore sensitivities of this effect to variations in the number of attachments. The theoretically predicted eigenfrequencies and insertion loss are compared with the dedicated experimental data.

ANALYSIS OF 100-METER RAIL TEMPERATURE FIELD DURING COOLING PROCESS BEFORE STRAIGHTENING BY FEM

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1203-1208 ◽  
Author(s):  
GE LI ◽  
HAIYAN CUI ◽  
LIN CHEN
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Finite Element ◽  
Temperature Field ◽  
Solid State ◽  
Phase Change ◽  
Cross Section ◽  
Physical Parameters ◽  
Cooling Process ◽  
Bending Deformation

The straightness of the 100-meter rail after straightening is directly affected by the bending deformation during cooling before straightening, and the analysis of the temperature field in the cooling process is the basis of studying the bending deformation. By analyzing the heat boundary conditions in the cooling process, the temperature field was calculated and its variable law was analyzed by using the 3-D transient non-liner finite element method. The factors such as the solid-state phase change and the physical parameters with change of the temperature were considered, and the numerical results were coincident with the experimental data. The results show that the velocities of temperature changing at different positions of the rail's cross-section are different in the cooling progress, and the phase change and the irregular cross-section of rail are important influencing factors.

An analytical approach for relating hardness and yield strength for materials with high ratio of yield strength to Young modulus

2004 ◽  
Vol 841 ◽  
Author(s):  
Luc J. Vandeperre ◽  
Finn Giuliani ◽  
William J. Clegg
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Elastic Modulus ◽  
Flow Stress ◽  
Yield Strength ◽  
Analytical Approach ◽  
Young Modulus ◽  
High Ratio ◽  
Finite Element Calculations ◽  
Analytical Expressions

ABSTRACTFor materials with a high ratio of Y to the elastic modulus, E, experimental data show that the ratio of the hardness to the flow stress decreases from 3 toward 1 as Y / E increases. This behaviour is predicted by finite element calculations but to date analytical expressions have not been able to correctly predict the relation between Y and H nor have they been able to show how the geometry of the indenter is important. Therefore, in this paper the correlation between H and Y for such materials is re-examined using an analytical approach to provide a physical interpretation, which explains the trends observed.

Fusion and Breakup Reactions of 17S + 208Pb and 15C + 232ThHalo Nuclei Systems

2015 ◽  
Vol 11 (2) ◽  
pp. 2972-2978
Author(s):  
Fouad A. Majeed ◽  
Yousif A. Abdul-Hussien
Keyword(s):  
Experimental Data ◽  
Cross Section ◽  
Fusion Reaction ◽  
Fusion Cross Section ◽  
Reaction Cross ◽  
Recent Experimental Data ◽  
Barrier Distribution ◽  
Coupled Channel ◽  
Total Fusion ◽  
Full Quantum

In this study the calculations of the total fusion reaction cross section have been performed for fusion reaction systems 17F + 208Pb and 15C + 232Th which involving halo nuclei by using a semiclassical approach.The semiclassical treatment is comprising the WKB approximation to describe the relative motion between target and projectile nuclei, and Continuum Discretized Coupled Channel (CDCC) method to describe the intrinsic motion for both target and projectile nuclei. For the same of comparsion a full quantum mechanical clacualtions have been preforemd using the (CCFULL) code. Our theorticalrestuls are compared with the full quantum mechaincialcalcuations and with the recent experimental data for the total fusion reaction  checking the stability of the distancesThe coupled channel calculations of the total fusion cross section σfus, and the fusion barrier distribution Dfus. The comparsion with experiment proves that the semiclassiacl approach adopted in the present work reproduce the experimental data better that the full quantal mechanical calcautions. 

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