Application of a Density-Elastic Modulus Equation Developed for the Distal Ulna to Multiple Forearm Positions: A Finite Element Study

2011 ◽  
Author(s):  
Mark A. C. Neuert ◽  
Rebecca L. Austman ◽  
Cynthia E. Dunning
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Material Properties ◽  
Experimental Studies ◽  
Strain Gauges ◽  
Stress And Strain ◽  
Distal Ulna ◽  
Strain Measurements ◽  
Multiple Loading ◽  
Element Study

Compared to experimental studies using strain gauges, finite element (FE) models are not limited to strain measurements at discrete locations and can be used to examine the continuous strain and stress field throughout bone. As such, they can be a useful tool for biomechanical investigations interested in stress and strain changes as a result of multiple loading conditions, implant designs, etc. Critical to their development is the assignment of material properties.

scholarly journals Effect of Fiber Geometry and Representative Volume Element on Elastic and Thermal Properties of Unidirectional Fiber-Reinforced Composites

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Siva Bhaskara Rao Devireddy ◽  
Sandhyarani Biswas
Keyword(s):  
Thermal Conductivity ◽  
Finite Element ◽  
Thermal Properties ◽  
Elastic Modulus ◽  
Cross Section ◽  
Representative Volume Element ◽  
Material Properties ◽  
Volume Element ◽  
Unidirectional Fiber ◽  
Representative Volume

The aim of present work is focused on the evaluation of elastic and thermal properties of unidirectional fiber-reinforced polymer composites with different volume fractions of fiber up to 0.7 using micromechanical approach. Two ways for calculating the material properties, that is, analytical and numerical approaches, were presented. In numerical approach, finite element analysis was used to evaluate the elastic modulus and thermal conductivity of composite from the constituent material properties. The finite element model based on three-dimensional micromechanical representative volume element (RVE) with a square and hexagonal packing geometry was implemented by using finite element code ANSYS. Circular cross section of fiber and square cross section of fiber were considered to develop RVE. The periodic boundary conditions are applied to the RVE to calculate elastic modulus of composite. The steady state heat transfer simulations were performed in thermal analysis to calculate thermal conductivity of composite. In analytical approach, the elastic modulus is calculated by rule of mixture, Halpin-Tsai model, and periodic microstructure. Thermal conductivity is calculated analytically by using rule of mixture, the Chawla model, and the Hashin model. The material properties obtained using finite element techniques were compared with different analytical methods and good agreement was achieved. The results are affected by a number of parameters such as volume fraction of the fibers, geometry of fiber, and RVE.

Limit Load Evaluation Using the mα-Tangent Multiplier in Conjunction With Elastic Modulus Adjustment Procedure

2013 ◽  
Vol 135 (5) ◽  
Author(s):  
S. L. Mahmood ◽  
R. Seshadri
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Satisfactory Agreement ◽  
Limit Load ◽  
Stress And Strain ◽  
Limit Loads ◽  
Adjustment Procedure ◽  
Tangent Method ◽  
Load Evaluation ◽  
Number Of Iterations

In this paper, the mα-tangent multiplier is used in conjunction with the elastic modulus adjustment procedure (EMAP) for limit load determination. This technique is applied to a number of mechanical components possessing different kinematic redundancies. By specifying spatial variations in the elastic modulus, numerous sets of statically admissible and kinematically admissible stress and strain distributions are generated, and limit loads for practical components are then determined using the mα-tangent method. The procedure ensures sufficiently accurate limit loads within a reasonable number of iterations. Results are compared with the inelastic finite element results and are found to be in satisfactory agreement.

MICRO-CONSTITUENT BASED VISCOELASTIC FINITE ELEMENT ANALYSIS OF BIOLOGICAL CELLS

2010 ◽  
Vol 02 (02) ◽  
pp. 229-249 ◽  
Author(s):  
F. CHENG ◽  
G. U. UNNIKRISHNAN ◽  
J. N. REDDY
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Reaction Force ◽  
Experimental Studies ◽  
Viscoelastic Model ◽  
Material Model ◽  
Outer Cortex ◽  
Element Analysis ◽  
Actin Cortex

A viscoelastic analysis of the biological cell considering the microcellular material properties is carried out in this work. Three separate regions of the cell: the actin cortex, cytoplasm and nucleus are considered. The outer cortex and cytoplasm are modeled using standard linear viscoelastic model (SLS) and standard neo-Hookean viscoelastic solid, and a linear elastic material model is considered for the nucleus. The effect of the material properties of cytoplasm and actin cortex on the derivable parameters from three major experimental studies of magnetic twisting cytometry (MTC) and atomic force microscopy (AFM) and micropipette aspiration (MPA) are analyzed using the finite element method. The bead center displacement for the MTC, reaction force for AFM, and aspiration length ratio for the MPA are the major quantities derived from the finite element analysis. A number of parametric studies are also conducted and it is observed that SLS and SnHS models predict nearly identical results for the material constants.

scholarly journals Finite element analysis relating shape, material properties, and dimensions of taenioglossan radular teeth with trophic specialisations in Paludomidae (Gastropoda)

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Material Properties ◽  
Stress And Strain ◽  
Plant Surface ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Force Volume ◽  
General Size

AbstractThe radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle. The latter was previously simulated for one species (Spekia zonata) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria grandis), covering sand (Cleopatra johnstoni), or attached to plant surface and covering sand (Bridouxia grandidieriana). Since the analysed radulae vary greatly in their general size (e.g. width) and size of teeth between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included S. zonata again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.

scholarly journals Finite Element Analysis Relating Shape, Material Properties, and Dimensions of Taenioglossan Radular Teeth with Trophic Specialisations in Paludomidae (Gastropoda)

2021 ◽  
Author(s):  
Wencke Krings ◽  
Jordi Marcé-Nogué ◽  
Stanislav N. Gorb
Keyword(s):  
Mechanical Properties ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Mechanical Behaviour ◽  
Material Properties ◽  
Stress And Strain ◽  
Plant Surface ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Force Volume

Abstract The radula, a chitinous membrane with embedded tooth rows, is the molluscan autapomorphy for feeding. The morphologies, arrangements and mechanical properties of teeth can vary between taxa, which is usually interpreted as adaptation to food. In previous studies, we proposed about trophic and other functional specialisations in taenioglossan radulae from species of African paludomid gastropods. These were based on the analysis of shape, material properties, force-resistance, and the mechanical behaviour of teeth, when interacting with an obstacle, which was previously simulated for one species (Spekia) by the finite-element-analysis (FEA) and, for more species, observed in experiments. In the here presented work, we test the previous hypotheses by applying the FEA on 3D modelled radulae, with incorporated material properties, from three additional paludomid species. These species forage either on algae attached to rocks (Lavigeria), covering sand (Cleopatra), or attached to plant surface and covering sand (Bridouxia). Since the analysed radulae vary greatly in their size between species, we additionally aimed at relating the simulated stress and strain distributions with the tooth sizes by altering the force/volume. For this purpose, we also included Spekia again in the present study. Our FEA results show that smaller radulae are more affected by stress and strain than larger ones, when each tooth is loaded with the same force. However, the results are not fully in congruence with results from the previous breaking stress experiments, indicating that besides the parameter size, more mechanisms leading to reduced stress/strain must be present in radulae.

3d Reconstruction and Nonlinear Finite Element Analysis of the Embryonic Left Ventricle

2007 ◽  
Author(s):  
Daniela Faas ◽  
Christine Buffinton ◽  
David Sedmera
Keyword(s):  
Finite Element ◽  
Left Ventricle ◽  
3D Reconstruction ◽  
Material Properties ◽  
Pressure Overload ◽  
Passive State ◽  
Stress And Strain ◽  
Element Analysis ◽  
Developing Heart ◽  
Element Technique

Changes in mechanical loading in the developing heart produce changes in morphology and mechanical material properties [1–3]. Understanding the relationship of these changes to mechanical stress and strain in the left ventricle requires a geometrically accurate model of the entire ventricle including the trabecular pattern and material property, boundary condition, and loading specification. A 3D reconstruction and finite element technique were developed to reconstruct the heart from serial confocal sections and calculate stress and strain distributions over the volume for the passive state. Control hearts and two treatments, pressure overload and pressure underload, were modeled. The results show that stresses in the trabeculae are much larger than those in the ventricular walls. Strains in the pressure-overloaded hearts were significantly smaller than in control or underloaded, indicating the stiffer material properties more than compensate for the increased internal pressure.

The Correction Factor in Elastic Modulus Determining by Indentation

2014 ◽  
Vol 887-888 ◽  
pp. 997-1000 ◽  
Author(s):  
P.M. Ogar ◽  
V.A. Tarasov ◽  
D.B. Gorokhov
Keyword(s):  
Finite Element ◽  
Elastic Modulus ◽  
Correction Factor ◽  
Indentation Load ◽  
Hardening Material ◽  
Finite Element Study ◽  
Plastic Hardening ◽  
Elastic Modules ◽  
Displacement Diagram ◽  
Element Study

The expression for the correction factor β, improving the accuracy of elastic modules measurement by sphere indentation is determined. It is shown that to determine β it is necessary determine the exponent in the equation of the loading curve, in additional to the previously determined parameters of the indentation load-displacement diagram. The computed exponent value of the unloading curve is given. It is shown that to analyze β can be used the results of finite element study of the sphere indentation in elastic-plastic hardening material.

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