Modeling of 3D Magnetostrictive Systems with Application to Galfenol and Terfenol-D Actuators

2012 ◽  
Vol 77 ◽  
pp. 11-28
Author(s):  
Marcelo J. Dapino ◽  
Suryarghya Chakrabarti
Keyword(s):  
Finite Element ◽  
Time Integration ◽  
Three Dimensional ◽  
Nonlinear Dynamic System ◽  
Element Model ◽  
Implicit Time ◽  
Integration Scheme ◽  
Modeling Framework ◽  
Time Integration Scheme ◽  
Parametric Analyses

This work presents a unified approach to model three dimensional magnetostrictive transducers. Generalized procedures are developed for incorporating nonlinear coupled constitutive behavior of magnetostrictive materials into an electro-magneto-mechanical finite element modeling framework. The finite element model is based on weak forms of Maxwell's equations for electromagnetics and Navier's equations for mechanical systems. An implicit time integration scheme is implemented to obtain nonlinear dynamic system responses. The model is implemented into a finite element (FE) solver and applied to two case studies, a Galfenol unimorph actuator and a magnetohydraulic Terfenol-D actuator for active engine mounts. Model results are compared with experiments, and parametric analyses are conducted which provide guidelines for optimization of actuator design.

scholarly journals IMPACT: an implicit time integration scheme for chemical species and families

2000 ◽  
Vol 18 (3) ◽  
pp. 337-346 ◽  
Author(s):  
G. D. Carver ◽  
P. A. Stott
Keyword(s):  
Middle Atmosphere ◽  
Time Integration ◽  
Three Dimensional ◽  
Chemical Species ◽  
Atmospheric Composition ◽  
Implicit Time ◽  
Integration Scheme ◽  
Implicit Time Integration ◽  
Time Integration Scheme ◽  
Complex Chemistry

Abstract. The implicit time integration scheme of Stott and Harwood (1993) was proposed as an efficient scheme for use in three-dimensional chemical models of the atmosphere. The scheme was designed for chemistry schemes using `chemical families', in which species with short lifetimes are grouped into longer-lived families. Further study with more complex chemistry, more species and reactions showed the scheme to be non-convergent and unstable under certain conditions; particularly for the perturbed chemical scenarios of polar stratospheric winters. In this work the scheme has been improved by revising the treatment of families and the convergence properties of the scheme. The new scheme has been named IMPACT (IMPlicit Algorithm for Chemical Time-stepping). It remains easy to implement and produces simulations that compare well with integrations using more accurate higher order schemes.Key words: Atmospheric composition and structure (middle atmosphere - composition and chemistry; lioposphere - composition and chemistry; instruments and techniques)

Dynamic Behaviour of Delaminated Composite Plate Under Blast Loading

2017 ◽  
Author(s):  
Chetan Kumar Hirwani ◽  
Subrata Kumar Panda ◽  
Siba Sankar Mahapatra ◽  
Sanjib Kumar Mandal ◽  
Apurba Kumar De
Keyword(s):  
Finite Element ◽  
Composite Plate ◽  
Degrees Of Freedom ◽  
Dynamic Behaviour ◽  
Time Integration ◽  
Blast Loading ◽  
Element Model ◽  
Continuity Condition ◽  
Integration Scheme ◽  
Time Integration Scheme

In the present article, the dynamic behaviour of the delaminated composite plate subjected to blast loading has been investigated. For the investigation, a general finite element model using higher-order mid-plane kinematics has been developed. The model has been discretised using nine noded isoparametric Lagrangian elements having nine degrees of freedom at each node. The continuity in the laminated and delaminated section has been established using the intermittent continuity condition. The final governing equation has been solved by applying Newmark’s time integration scheme in conjunction with finite element steps. Further, the said responses have been evaluated by developing an in-house MATLAB code based on the proposed model. In order to illustrate the consistency and accuracy of the present model, convergence and comparison study has been conducted i.e. the responses are evaluated for different mesh sizes and compared them with those of responses of earlier published literature. Finally, various examples have been solved to illustrate the influence of the size and position of debonding, side to thickness ratio, aspect ratio and end condition on the dynamic response of composite structure and discussed in detail.

scholarly journals An investigation of stress inaccuracies and proposed solution in the material point method

2019 ◽  
Vol 65 (2) ◽  
pp. 555-581 ◽  
Author(s):  
José Leόn González Acosta ◽  
Philip J. Vardon ◽  
Guido Remmerswaal ◽  
Michael A. Hicks
Keyword(s):  
Shape Function ◽  
Time Integration ◽  
Three Dimensional ◽  
Constitutive Models ◽  
Material Point Method ◽  
Material Point ◽  
Point Method ◽  
Implicit Time ◽  
Integration Scheme ◽  
Time Integration Scheme

AbstractStress inaccuracies (oscillations) are one of the main problems in the material point method (MPM), especially when advanced constitutive models are used. The origins of such oscillations are a combination of poor force and stiffness integration, stress recovery inaccuracies, and cell crossing problems. These are caused mainly by the use of shape function gradients and the use of material points for integration in MPM. The most common techniques developed to reduce stress oscillations consider adapting the shape function gradients so that they are continuous at the nodes. These techniques improve MPM, but problems remain, particularly in two and three dimensional cases. In this paper, the stress inaccuracies are investigated in detail, with particular reference to an implicit time integration scheme. Three modifications to MPM are implemented, and together these are able to remove almost all of the observed oscillations.

A Finite Element Analysis for Unbonded Flexible Risers Under Axial Tension

2008 ◽  
Author(s):  
Ali Bahtui ◽  
Hamid Bahai ◽  
Giulio Alfano
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Time Integration ◽  
Element Model ◽  
Integration Scheme ◽  
Element Analysis ◽  
Time Integration Scheme ◽  
Flexible Risers ◽  
Benchmark Solutions ◽  
The Finite Element Model

Recent developments on the numerical analysis of detailed finite element models of unbonded flexible risers using ABAQUS are presented. Several analytical methods are studied and combined together, and their results are compared with those obtained in the finite element model for two different tests, the second one involving cyclic loading. In the finite element model all layers are modeled separately and contact interfaces are placed between each layer. A fully explicit time-integration scheme was used on a 16-processor cluster. The very good agreement found from numerical and analytical comparisons validates the use of our numerical model to provide benchmark solutions against which further detailed investigation will be made.

A Non-Linear Aeroelasticity Analysis of a Fan Blade Using Unstructured Dynamic Meshes

1996 ◽  
Vol 210 (6) ◽  
pp. 549-564 ◽  
Author(s):  
M Vahdati ◽  
M Imregun
Keyword(s):  
Time Integration ◽  
Three Dimensional ◽  
Leading Edge ◽  
Element Model ◽  
Mode Shapes ◽  
Implicit Time ◽  
Integration Scheme ◽  
Central Difference ◽  
Basic Fluid ◽  
Fan Blade

The main objective of this paper is to present a methodology for the three-dimensional aeroelasticity analysis of turbomachinery blades using an unstructured compressible Navier-Stokes solver for the fluid and a modal model for the structure. The basic fluid solver is constructed in the form of a central difference scheme with explicitly added artificial dissipation which is based upon the fourth- and second-order differences of the solution. The temporal discretization uses an implicit time integration scheme based on a Jacobi relaxation procedure. The structural modes of vibration are determined via a finite element model and the mode shapes are interpolated on to the fluid mesh in a manner that is consistent with general unstructured tetrahedral grids. A spring analogy algorithm that can move the mesh according to the instantaneous shape of a deforming blade has been developed for the accurate tracking of the solid boundaries without creating excessive grid distortions. The performance of the resulting system was examined by considering the aeroelastic behaviour of NASA Rotor 67 fan blade and predictions were compared to experimental results wherever possible. Using a three-dimensional cyclic symmetry model, the tip leading edge time histories were predicted under peak-efficiency and near-stall conditions, and the corresponding aeroelastic natural frequencies and aerodynamic damping values were determined. The blade was found to be stable in all cases considered.

Numerical and Analytical Modeling of Unbonded Flexible Risers

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
A. Bahtui ◽  
H. Bahai ◽  
G. Alfano
Keyword(s):  
Finite Element ◽  
Time Integration ◽  
Computational Cost ◽  
Element Model ◽  
Integration Scheme ◽  
Element Analysis ◽  
Axial Tension ◽  
External Pressures ◽  
Time Integration Scheme ◽  
Flexible Risers

This paper presents an analytical formulation and a finite element analysis of the behavior of multilayer unbonded flexible risers. The finite element model accurately incorporates all the fine details of the riser that were previously considered to be important but too difficult to simulate due to the significant associated computational cost. All layers of the riser are separately modeled, and contact interaction between layers has been accounted for. The model includes geometric nonlinearity as well as frictional effects. The analysis considers the main modes of flexible riser loading, which include internal and external pressures, axial tension, torsion, and bending. Computations were performed by employing a fully explicit time integration scheme on a parallel 16-processor cluster of computers. Consistency of simulation results was demonstrated by comparison with those of the analytical model of an identical structure. The close agreement gives confidence in both approaches.

Transonic Flow Computations in Cascades Using Finite Element Method

1981 ◽  
Vol 103 (4) ◽  
pp. 657-664 ◽  
Author(s):  
H. U. Akay ◽  
A. Ecer
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Transonic Flow ◽  
Method Development ◽  
Time Integration ◽  
Integration Scheme ◽  
Complex Flow ◽  
Time Integration Scheme ◽  
Naca 0012 ◽  
Element Method

Analysis of transonic flow through a cascade of airfoils is investigated using the finite element method. Development of a computational grid suitable for complex flow structures and different types of boundary conditions is presented. An efficient pseudo-time integration scheme is developed for the solution of equations. Modeling of the shock and the convergence characteristics of the developed scheme are discussed. Numerical results include a 45 deg staggered cascade of NACA 0012 airfoils with inlet flow Mach number of 0.8 and angles of attack 1, 0, and −1 deg.

Numerical Analysis of Solute Segregation in Directional Solidification under Static Magnetic Field

2011 ◽  
Vol 312-315 ◽  
pp. 253-258 ◽  
Author(s):  
Sabrina Nouri ◽  
Mouhamed Benzeghiba ◽  
Ahmed Benzaoui
Keyword(s):  
Magnetic Field ◽  
Static Magnetic Field ◽  
Time Integration ◽  
Magnetic Field Effect ◽  
Computer Code ◽  
Thermosolutal Convection ◽  
Implicit Time ◽  
Integration Scheme ◽  
Dimensional Solution ◽  
Time Integration Scheme

This paper addresses the effect of thermosolutal convection in the formation of defects in directionally solidified alloys. The numerical model is based on a bi-dimensional solution consisting of an implicit time integration scheme to couple thermal and solutal fields, which is supported by a finite volume numerical modeling technique. In this article, the macrosegregation phenomenon under a static magnetic field effect is analyzed numerically by a computer code developed and validated with experimental data. The numerically obtained results have been widely discussed in dependence of the characteristic parameters of the studied problem.

Time Integration of Impact Phenomena in Solid Mechanics: A One-Dimensional Model Problem

1996 ◽  
Author(s):  
V. Chawla ◽  
T. A. Laursen
Keyword(s):  
Finite Element ◽  
Solid Mechanics ◽  
Exact Analytical Solution ◽  
Time Integration ◽  
Dynamic Contact ◽  
Momentum Conservation ◽  
Integration Scheme ◽  
Mass System ◽  
Element Discretization ◽  
Time Integration Scheme

Abstract 1D impact between two identical bars is modeled as a simple spring-mass system as would be generated by a finite element discretization. Some commonly used time integrators are applied to the system to demonstrate defects in the numerical solution as compared to the exact analytical solution. Using energy conservation as the criterion for stability, a new time integration scheme is proposed that imposes a persistency condition for dynamic contact. Finite element simulation with Lagrange multipliers for enforcing the contact constraints shows exact energy and momentum conservation.

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