A Study of the Dynamic Behavior of Elastomeric Materials Using Finite Elements

1996 ◽  
Vol 118 (4) ◽  
pp. 503-508 ◽  
Author(s):  
G. E. Vallee ◽  
Arun Shukla
Keyword(s):  
Finite Element ◽  
Dynamic Behavior ◽  
Split Hopkinson Pressure Bar ◽  
Material Model ◽  
Element Model ◽  
Material Behavior ◽  
Hopkinson Pressure Bar ◽  
Material Models ◽  
Finite Element Program ◽  
Elastomeric Materials

A numerical method is described for determining a dynamic finite element material model for elastomeric materials loaded primarily in compression. The method employs data obtained using the Split Hopkinson Pressure Bar (SHPB) technique to define a molecular constitutive model for elastomers. The molecular theory is then used to predict dynamic material behavior in several additional deformation modes used by the ABAQUS/Explicit (Hibbitt, Karlsson, and Sorenson, 1993a) commercial finite element program to define hyperelastic material behavior. The resulting dynamic material models are used to create a finite element model of the SHPB system, yielding insights into both the accuracy of the material models and the SHPB technique itself when used to determine the dynamic behavior of elastomeric materials. Impact loading of larger elastomeric specimens whose size prohibits examination by the SHPB technique are examined and compared to the results of dynamic load-deflection experiments to further verify the dynamic material models.

Numerical Analysis of the Influence of Material Model on Response of Compressed Imperfect Thin-Walled Channel

2014 ◽  
Vol 611 ◽  
pp. 188-193 ◽  
Author(s):  
Vladimír Ivančo ◽  
Gabriel Fedorko ◽  
Ladislav Novotný
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Model Selection ◽  
Finite Element Model ◽  
Material Model ◽  
Element Model ◽  
Material Models ◽  
Geometric Imperfections ◽  
Walled Channel ◽  
Thin Walled

In the paper, the influence of material model selection on the behaviour of Finite Element model of a compressed thin-walled channel is studied. Results of three material models of channels of two different lengths and two types of geometric imperfections are compared and discussed.

Finite Element Analysis of Synchronous Belt Tooth Failure

1993 ◽  
Vol 207 (2) ◽  
pp. 145-153 ◽  
Author(s):  
K W Dalgarno ◽  
A J Day ◽  
T H C Childs
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Model ◽  
Element Model ◽  
Element Analysis ◽  
Finite Element Program ◽  
Interface Elements ◽  
Dimensional Finite Element ◽  
Element Program ◽  
Critical Strains

This paper describes a finite element analysis of a synchronous belt tooth under operational loads and conditions with the objective of obtaining a greater understanding of belt failure by tooth root cracking through an examination of the strains within the facing fabric in the belt. The analysis used the ABAQUS finite element program, and was based on a two-dimensional finite element model incorporating a hyperelastic material model for the elastomer compound. Contact between the belt tooth face and the pulley groove was modelled using surface interface elements which allowed only compression and shear forces at the contact surfaces. It is concluded that the critical strains in the facing fabric of the belt, and therefore the belt life, are largely determined by the tangential loading condition on the belt teeth.

Implementation of the Nonlocal Microplane Concrete Model Within an Explicit Dynamic Finite Element Program

1992 ◽  
Vol 45 (3S) ◽  
pp. S132-S139 ◽  
Author(s):  
William F. Cofer
Keyword(s):  
Finite Element ◽  
Strain Tensor ◽  
Material Model ◽  
Material Behavior ◽  
Concrete Material ◽  
Finite Element Program ◽  
Dynamic Finite Element ◽  
Weighted Integral ◽  
Element Program ◽  
Explicit Dynamic

The microplane concrete material model is based upon assumptions regarding the behavior of the material components. At any point, the response to the strain tensor on arbitrarily oriented surfaces is considered. Simple, softening stress-strain relationships are assumed in directions perpendicular and parallel to the surfaces. The macroscopic material behavior is then composed of the sum of the effects. The implementation of this model into the explicit, nonlinear, dynamic finite element program, DYNA3D, is described. To avoid the spurious mesh sensitivity that accompanies material failure, a weighted integral strain averaging approach is used to ensure that softening is nonlocal. This method is shown to be effective for limiting the failure zone in a concrete rod subjected to an impulse loading.

Finite Element Modeling of Tire With Validation Using Tensile and Frequency Response Testing

2014 ◽  
Author(s):  
Jennifer M. Bastiaan ◽  
Amir Khajepour
Keyword(s):  
Finite Element ◽  
Uniaxial Tension ◽  
Material Model ◽  
Element Model ◽  
Test Results ◽  
Material Models ◽  
Modal Damping ◽  
Hyper Elastic ◽  
Response Testing ◽  
Tread Rubber

A physical testing program is performed in support of finite element model creation for a 50-series passenger car tire. ABAQUS finite element analysis software is used along with its standard material models. Uniaxial tension testing of tire samples cut from the tread composite, tread rubber and sidewall composite is performed in order to obtain material properties. Hyper-elastic material coefficients for tread rubber are fit using uniaxial tension test data. Results show that the Arruda-Boyce hyper-elastic material model fits the test data well and it predicts reasonable overall behavior in uniaxial tension and uniaxial compression. Most other hyperelastic material models are found to predict unrealistic behavior in uniaxial compression for the tire samples, especially in the 0 to 20% compressive strain range. Frequency response testing of two inflated passenger car tires of different sizes, makes and models is also performed to assist in defining the viscoelastic material model for tread rubber. Test results show that tire modal damping is in the 2 to 4% range for most modes below 200 Hz, and the response curves, modal density and modal damping are remarkably similar for the two tires tested. The tire finite element model with updated material properties is simulated for nine combinations of air inflation pressure and vertical load in order to calculate static loaded radius. The analysis results are compared with physical test results and the analysis results are found to deviate at most by 3% compared to the tests.

The Parametric Studies of Brain Materials in the Analysis of Head Impact

2006 ◽  
Author(s):  
Dalong Li ◽  
Mariusz Ziejewski ◽  
Ghodrat Karami
Keyword(s):  
Finite Element ◽  
Dynamic Response ◽  
Dynamic Behavior ◽  
Material Properties ◽  
Material Behavior ◽  
Material Models ◽  
Material Parameters ◽  
Multiple Materials ◽  
The Brain ◽  
Brain Tissues

Crash analysis and head injury biomechanics are very important fields in biomedical research due to the devastating consequences of traumatic brain injuries (TBI). Complex geometry and constitutive models of multiple materials can be combined with the loading conditions in finite element head model to study the dynamic behavior of brain and the TBI. In such a modeling, the proper regional material properties of brain tissues are important. Brain tissues material properties have not been finally determined by experiments, and large variations in the test data still exist and the data is very much situation-dependent. Therefore, parametric analysis should be performed to study the relationship between the material properties and the brain response. The main purpose of presenting this paper is to identify the influence of material constitutive properties on brain impact response, to search for an improved material model and to arrive at a better correlation between the finite element model and the cadaver tests data. In this paper a 3-D nonlinear finite element method will be used to study the dynamic response of the human head under dynamic loading. The finite element formulation includes detailed model of the skull, brain, cerebral-spinal fluid (CSF), dura mater, pia mater, falx and tentorium membranes. The brain is modeled as linear viscoelastic material, whereas linear elastic material behavior is assumed for all the other tissue components. The proper contact and compatibility conditions between different components have been implemented in the modeling procedure. The results for the direct frontal impacts will be shown for three groups of material parameters. The parametrical analysis of tissue material models allows to examines the accuracy of three different set of material parameters for brain in a comparison with the prediction of the head dynamic response of Nahum's human cadaver direct impact experiment. Three sets of suggested material parameters are examined. It is concluded that although all three groups of material models will follow the dynamic behavior of the head and brain behavior, but the parametric data considered in this paper have a closer resemblance to the experimental behavior.

scholarly journals Dynamic Behavior of Advanced Ti Alloy under Impact Loading: Experimental and Numerical Analysis

2011 ◽  
Vol 70 ◽  
pp. 207-212
Author(s):  
Murat Demiral ◽  
Anish Roy ◽  
Vadim V. Silberschmidt
Keyword(s):  
Numerical Analysis ◽  
Strain Rate ◽  
High Strain ◽  
Split Hopkinson Pressure Bar ◽  
Three Dimensional ◽  
Element Model ◽  
Industrial Applications ◽  
Material Behavior ◽  
Hopkinson Pressure Bar ◽  
Strain And Strain Rate

Industrial applications of Ti-based alloys, especially in aerospace, marine and offshore industries, have grown significantly over the years primarily due to their high strength, light weight as well as good fatigue and corrosion-resistance properties. A combination of experimental and numerical studies is necessary to predict a material behavior of such alloys under high strain-rate conditions characterized also by a high level of strains accompanied by high temperatures. A Split Hopkinson Pressure Bar (SHPB) technique is a commonly used experimental method to characterize a dynamic stress-strain response of materials at high strain rates. In a SHPB test, the striker bar is shot against the free end of the incident stress bar, which on impact generates a stress pulse propagating in the incident bar towards the specimen sandwiched between the incident and transmitted bars. An experimental study and a numerical analysis based on a three-dimensional finite element model of the SHPB experiment are performed in this study to assess various features of the underlying mechanics of deformation processes of the alloy tested at high-strain and -strain-rate regimes.

Experimental and numerical analysis of stress wave propagation in polymers and the role of interfaces in armour systems

2012 ◽  
Vol 2 (4) ◽  
Author(s):  
Chandragupt Gorwade ◽  
Ian Ashcroft ◽  
Vadim Silberschmidt ◽  
Foz Hughes ◽  
Gerry Swallowe
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Split Hopkinson Pressure Bar ◽  
Polymeric Materials ◽  
Element Model ◽  
Stress Wave Propagation ◽  
Hopkinson Pressure Bar ◽  
Impedance Mismatch ◽  
Stress And Deformation

AbstractAdvanced polymeric materials are finding an increasing range of industrial and defence applications. These materials have the potential to improve combat survivability, whilst reducing the cost and weight of armour systems. In this paper the results from a split Hopkinson pressure bar (SHPB) test of a high density polyethylene (HDPE) sample involving multiple stress waves is discussed with aid of a finite element model of the test. It is seen that the phenomenon of impedance mismatch at interfaces plays an important role in the levels of stress and deformation seen in the sample. A multi-layer armour system is then investigated using the finite element model. This case study illustrates the role of impedance mismatch and interface engineering in the design and optimisation of armour solutions.

FEM Simulation of a Magnetic Shape Memory Foil Actuator Under Different Loading Conditions

2011 ◽  
Author(s):  
B. Krevet ◽  
M. Kohl ◽  
V. Pinneker
Keyword(s):  
Finite Element ◽  
Shape Memory ◽  
Fem Simulation ◽  
Material Model ◽  
Element Model ◽  
Magnetic Shape Memory ◽  
Finite Element Program ◽  
Model And Simulation ◽  
Element Program ◽  
Mechanical Spring

This paper presents a finite element model and simulation results on the performance of a novel linear actuator using the magnetic shape memory (MSM) effect in a Ni-Mn-Ga foil loaded by a mechanical spring. We present finite element simulations with a material model based on the thermodynamic Gibbs free energy in a finite element program (FEM) using beam elements, which is combined with an integral magnetic solver. The simulations qualitatively describe the observed tensile stress-dependence of magneto strain of a first demonstrator of a MSM foil actuator. We demonstrate that complete reversible cycles of the magnetic field induced strain are possible if the spring is preloaded to induce a prestress in the foil. The effect of inhomogeneous material on variant reorientation and corresponding magneto strain are discussed.

Finite Element Implementation of Anisotropic Quasi-Linear Viscoelasticity Using a Discrete Spectrum Approximation

1998 ◽  
Vol 120 (1) ◽  
pp. 62-70 ◽  
Author(s):  
M. A. Puso ◽  
J. A. Weiss
Keyword(s):  
Finite Element ◽  
Discrete Spectrum ◽  
Soft Tissues ◽  
Transversely Isotropic ◽  
Material Model ◽  
Material Behavior ◽  
Elastic Response ◽  
Test Problems ◽  
Finite Element Program ◽  
Finite Element Implementation

The objective of this work was to develop a theoretical and computational framework to apply the finite element method to anisotropic, viscoelastic soft tissues. The quasi-linear viscoelastic (QLV) theory provided the basis for the development. To allow efficient and easy computational implementation, a discrete spectrum approximation was developed for the QLV relaxation function. This approximation provided a graphic means to fit experimental data with an exponential series. A transversely isotropic hyperelastic material model developed for ligaments and tendons was used for the elastic response. The viscoelastic material model was implemented in a general-purpose, nonlinear finite element program. Test problems were analyzed to assess the performance of the discrete spectrum approximation and the accuracy of the finite element implementation. Results indicated that the formulation can reproduce the anisotropy and time-dependent material behavior observed in soft tissues. Application of the formulation to the analysis of the human femur-medial collateral ligament–tibia complex demonstrated the ability of the formulation to analyze large three-dimensional problems in the mechanics of biological joints.

scholarly journals Integrated Experimental, Atomistic, and Microstructurally Based Finite Element Investigation of the Dynamic Compressive Behavior of 2139 Aluminum

2009 ◽  
Vol 76 (5) ◽  
Author(s):  
K. Elkhodary ◽  
Lipeng Sun ◽  
Douglas L. Irving ◽  
Donald W. Brenner ◽  
G. Ravichandran ◽  
...  
Keyword(s):  
Finite Element ◽  
Density Functional ◽  
Mechanical Response ◽  
Split Hopkinson Pressure Bar ◽  
Density Functional Theory Calculations ◽  
Element Model ◽  
Hopkinson Pressure Bar ◽  
Element Analysis ◽  
Spatial And Temporal Scales ◽  
Orientation Relations

The objective of this study was to identify the microstructural mechanisms related to the high strength and ductile behavior of 2139-Al, and how dynamic conditions would affect the overall behavior of this alloy. Three interrelated approaches, which span a spectrum of spatial and temporal scales, were used: (i) The mechanical response was obtained using the split Hopkinson pressure bar, for strain-rates ranging from 1.0×10−3 s to 1.0×104 s−1. (ii) First principles density functional theory calculations were undertaken to characterize the structure of the interface and to better understand the role played by Ag in promoting the formation of the Ω phase for several Ω-Al interface structures. (iii) A specialized microstructurally based finite element analysis and a dislocation-density based multiple-slip formulation that accounts for an explicit crystallographic and morphological representation of Ω and θ′ precipitates and their rational orientation relations were conducted. The predictions from the microstructural finite element model indicated that the precipitates continue to harden and also act as physical barriers that impede the matrix from forming large connected zones of intense plastic strain. As the microstructural FE predictions indicated, and consistent with the experimental observations, the combined effects of θ′ and Ω, acting on different crystallographic orientations, enhance the strength and ductility, and reduce the susceptibility of 2139-Al to shear strain localization due to dynamic compressive loads.

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