Viscoelastic Finite-Element Modelling of Neutrophil Deformation in a Tapered Micropipette

2008 ◽  
Author(s):  
Soo Kng Teo ◽  
Kim H. Parker ◽  
K.-H. Chiam
Keyword(s):  
Finite Element ◽  
Computational Modeling ◽  
Equilibrium State ◽  
Finite Element Model ◽  
Rheological Properties ◽  
Finite Element Modelling ◽  
Element Model ◽  
Temporal Variations ◽  
Quantitative Information ◽  
Element Modelling

In this paper, we discuss the results arising from using a viscoelastic, axisymmetric finite-element model [1] to study the aspiration of neutrophils into a tapered micropipette [2]. The key feature of our model is that we take into account the experimentally observed temporal variations in the rheological properties of deforming neutrophils [3]. We show that our model successfully reproduces the equilibrium state reached by a neutrophil subjected to a constant step pressure [2]. We are also able to extract quantitative information about the rate at which the rheological properties of the neutrophil change. Such information may be difficult to obtain directly from the experiments themselves. Thus, our approach illustrates the usefulness of computational modeling as a complement to experiments.

scholarly journals Validation of a wide plate finite element model using digital image correlation

2011 ◽  
Vol 2 (3) ◽  
pp. 416-423
Author(s):  
K. De Keyser ◽  
F. Van Acker ◽  
Stijn Hertelé ◽  
Matthias Verstraete ◽  
Wim De Waele ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modelling ◽  
Element Model ◽  
Image Correlation ◽  
Defect Tolerance ◽  
Plastic Deformations ◽  
Test Setup ◽  
Element Modelling ◽  
Weld Defect

To investigate the influence of global plastic deformations on girth weld defect tolerance inpipelines, a parametric finite element model has been developed. This paper provides an experimentalvalidation of the model. It describes the test setup and instrumentation used for the evaluation of plasticstrain fields around a notch in a tension loaded non-welded X65 mini wide plate. LVDT measurements anddigital image correlation (DIC) results are compared to each other and to the results of finite elementsimulations. Whereas some deviation is observed owing to unavoidable experimental uncertainties andlimitations of finite element modelling, the overall correspondence is more than satisfying.

scholarly journals Comparison of Meshing Strategies in THR Finite Element Modelling

Materials ◽  
2019 ◽  
Vol 12 (14) ◽  
pp. 2332 ◽  
Author(s):  
Alessandro Ruggiero ◽  
Roberto D’Amato ◽  
Saverio Affatato
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modelling ◽  
Internal Surface ◽  
Element Model ◽  
Computational Effort ◽  
Von Mises Stress ◽  
Acetabular Cup ◽  
Element Modelling ◽  
Multibody Model

In biomechanics and orthopedics, finite element modelling allows simulating complex problems, and in the last few years, it has been widely used in many applications, also in the field of biomechanics and biotribology. As is known, one crucial point of FEM (finite element model) is the discretization of the physical domain, and this procedure is called meshing. A well-designed mesh is necessary in order to achieve accurate results with an acceptable computational effort. The aim of this work is to test a finite element model to simulate the dry frictionless contact conditions of a hip joint prosthesis (a femoral head against an acetabular cup) in a soft bearing configuration by comparing the performances of 12 common meshing strategies. In the simulations, total deformation of the internal surface of the cup, contact pressure, and the equivalent von Mises stress are evaluated by using loads and kinematic conditions during a typical gait, obtained from a previous work using a musculoskeletal multibody model. Moreover, accounting for appropriate mesh quality metrics, the results are discussed, underlining the best choice we identified after the large amount of numerical simulations performed.

Crystal Plasticity Finite Element Modelling of BCC Deformation Texture in Cold Rolling

2008 ◽  
Vol 32 ◽  
pp. 251-254 ◽  
Author(s):  
Hei Jie Li ◽  
Jing Tao Han ◽  
Zheng Yi Jiang ◽  
Hua Chun Pi ◽  
Dong Bin Wei ◽  
...  
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Crystal Plasticity ◽  
Finite Element Modelling ◽  
Rolling Texture ◽  
Element Model ◽  
Deformation Texture ◽  
Type Model ◽  
Element Modelling ◽  
Crystal Plasticity Finite Element

Taylor-type and finite element polycrstal models have been embedded into the commercial finite element code ABAQUS to carry out the crystal plasticity finite element modelling of BCC deformation texture based on rate dependent crystal constitutive equations. Initial orientations measured by EBSD were directly used in crystal plasticity finite element model to simulate the development of rolling texture of IF steel under various reductions. The calculated results are in good agreement with the experimental values. The predicted and measured textures tend to sharper with an increase of reduction, and the texture obtained from the Taylor-type model is much stronger than that by finite element model. The rolling textures calculated with 48 {110}<110>, {112}<111> and {123}<111> slip systems are close to the EBSD results.

Finite Element Modelling Of Compartment Fire Using ABAQUS

2015 ◽  
Vol 74 (4) ◽  
Author(s):  
Mariyana A. A. K. ◽  
A. S. M. Abdul Awal ◽  
Mahmood Md. Tahir
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Elevated Temperature ◽  
Finite Element Model ◽  
Finite Element Modelling ◽  
Fire Test ◽  
Element Model ◽  
Compartment Fire ◽  
Element Modelling ◽  
The Finite Element Model

This paper presents finite element modelling (FEM) of a reinforced concrete (RC) frame subjected to elevated temperature. The work presented is part of the UK-India Education and Research Initiative (UKIERI) project. In this project, an experimental test of sub-assemblage frame with elevated temperature has been performed at Indian Institute of Technology (IIT) Roorkee, India. The finite element model using ABAQUS software has been used to validate the increased in temperature distribution on reinforced concrete frame exposed to fire. The idea of this study is to design a compartment fire, and determination of emissivity value at different height. And composition of hot gases was calculated. Gas temperatures used was based on the average temperature-curve obtained in the fire test. The validity of the finite element model was established by comparing the predicted values from the FEM with test data direct from fire test results. The results obtained indicate that suggested FEM analysis procedure is capable of modelling temperature in compartment fires.  

Impact Analysis of an Oxygen Mask Locking Panel of Aircraft Using Finite Element Modelling

2014 ◽  
Vol 657 ◽  
pp. 735-739 ◽  
Author(s):  
Emilian Ionut Croitoru ◽  
Gheorghe Oancea
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Impact Analysis ◽  
Element Model ◽  
Composite Panel ◽  
Cad Model ◽  
Stress Variation ◽  
Element Modelling ◽  
Oxygen Mask ◽  
The Impact

This paper presents a method of finite element modelling used for the impact analysis of a composite panel. In this research, the composite panel consists of an oxygen mask locking panel of an aircraft. This panel is loaded with one concentrated abuse loading and three uniform distributed abuse loading cases and the stress variation within the composite panel for each load case is determined. In order to assess the impact analysis on the oxygen mask panel of the aircraft, a finite element model is created using Patran as the main application for pre/post-processing and Nastran as the main processor. The paper also presents a comparison between results obtained using the same finite element modelling of the composite panel CAD model of the panel with four load cases with different material types. The results are used to determine the most capable material stresswise.

Finite-Element Modelling of Ballistic Impact of Plain-Woven Aramid Fabric

2014 ◽  
Vol 553 ◽  
pp. 769-773 ◽  
Author(s):  
E.A. Flores-Johnson ◽  
J.G. Carrillo ◽  
R.A. Gamboa ◽  
Lu Ming Shen
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modelling ◽  
Permanent Deformation ◽  
Element Model ◽  
Ballistic Impact ◽  
Elastic Model ◽  
Numerical Predictions ◽  
Aramid Fabric ◽  
The Finite Element Model

In this work, a 3D finite-element model of the ballistic impact of a multi-layered plain-woven aramid fabric style 720 (Kevlar®129 fibre, 1420 denier, 20×20 yarns per inch) impacted by a 6.7-mm spherical projectile was built at the mesoscale in Abaqus/Explicit by modelling individual crimped yarns. Material properties and yarn geometry for the model were obtained from reported experimental observations. An orthotropic elastic model with a failure criterion based on the tensile strength of the yarns was used. Numerical predictions were compared with available experimental data. It was found that the finite-element model can reproduce the physical experimental observations, such as the straining of primary yarns and pyramidal-shaped deformation after perforation. The permanent deformation of fabric targets predicted by the numerical simulations was compared with available experimental results. It was found that the model fairly predicted the permanent deformation with a difference of about 21% when compared with experiments.

A wheel passing a crossing nose: Dynamic analysis under high axle loads using finite element modelling*

2012 ◽  
Vol 226 (6) ◽  
pp. 603-611 ◽  
Author(s):  
Martin Pletz ◽  
Werner Daves ◽  
Heinz Ossberger
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Element Model ◽  
Contact Forces ◽  
Element Modelling ◽  
Multiple Contacts ◽  
Load Train ◽  
Proposed Model ◽  
Train Speed ◽  
Axle Loads

A finite element model for the process of a wheel passing a crossing is presented. In the dynamic model, one wheel, the wing rails and the crossing nose (frog) are modelled. The bogie, the complete wheel set and the support of the crossing are represented as a system consisting of masses, springs, dampers and friction-generating elements. The rolling/sliding behaviour between the wheel and crossing is studied using the proposed model. Due to the conical shape of the wheel tread and multiple contacts between the wheel and the crossing parts, sliding occurs during the transition of the wheel from the wing rail to the crossing nose or vice versa. At the same time, an impact occurs that produces high contact forces. The parameters of the model are the train speed and passing direction, the wheel and the crossing geometry, the axle load and the support of the crossing. In this paper, the crossover process is studied for high axle loads and compared with results of simulations using a normal axle load. Further parameters are three train velocities, both directions of passing and different crossing materials. The loading of the crossing nose is calculated for all cases (axle load, train speed and direction) and materials.

scholarly journals Informed Finite Element Modelling for Wire and Arc Additively Manufactured Metallics—A Case Study on Modular Building Connections

Buildings ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 5
Author(s):  
Madhushan Dissanayake ◽  
Thadshajini Suntharalingam ◽  
Konstantinos Daniel Tsavdaridis ◽  
Keerthan Poologanathan ◽  
Gatheeshgar Perampalam
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Three Dimensional ◽  
Element Model ◽  
Element Modelling ◽  
Proposed Model ◽  
Dimensional Finite Element ◽  
3D Printed ◽  
Three Dimensional Finite Element

The use of 3D printing in modular building connections is a novel and promising technique. However, the performance of 3D printed steel modular building connections has not been investigated adequately to date. Therefore, this paper presents a three-dimensional finite element model (FEM), using the multi-purpose software Abaqus, to study the effect of different geometrical and material parameters on the ultimate behaviour of modular building connections (herein named 3DMBC) using a wire and arc additive manufacturing (WAAM) method, as part of the UK’s 3DMBC (3D Modular Building Connections) project. The proposed model considers material and geometrical non-linearities, initial imperfections, and the contact between adjacent surfaces. The finite element results are compared with the currently available experimental results and validated to ensure developed FEM can be used to analyse the behaviour of 3DMBC with some adjustments. Case studies were investigated using the validated model to analyse the ultimate behaviour with different nominal and WAAM-produced materials under various loading arrangements. Based on the results, it is recommended to conservatively use the treated or untreated WAAM material properties obtained in θ = 90° print orientation in the finite element modelling of 3DMBCs considering the complex component arrangements and multi-directional loading in the modular connections. It is also noted that the thickness of beams and columns of fully 3D printed connections can be increased to achieve the same level of performance as traditional modular connections. For the 3DMBCs printed using untreated WAAM, the thickness increment was found to be 50% in this study.

Mesh Convergence Studies for Thin Shell Elements Developed by the ASME Task Group on Computational Modeling

2011 ◽  
Author(s):  
Gordon S. Bjorkman ◽  
David P. Molitoris
Keyword(s):  
Finite Element ◽  
Computational Modeling ◽  
Finite Element Model ◽  
Thin Shell ◽  
Element Model ◽  
Task Group ◽  
Plastic Strains ◽  
Shell Elements ◽  
Explicit Dynamics

The ASME Task Group on Computational Modeling for Explicit Dynamics was founded in August 2008 for the purpose of creating a quantitative guidance document for the development of finite element models used to analyze energy-limited events using explicit dynamics software. This document will be referenced in the ASME Code Section III, Division 3 and the next revision of NRC Regulatory Guide 7.6 as a means by which the quality of a finite element model may be judged. One portion of the document will be devoted to a series of element convergence studies that can aid designers in establishing the mesh refinement requirements necessary to achieve accurate results for a variety of different elements types in regions of high plastic strain. These convergence studies will also aid reviewers in evaluating the quality of a finite element model and the apparent accuracy of its results. In this paper the authors present the results of a convergence study for an impulsively loaded propped cantilever beam constructed of LS-DYNA thin shell elements using both reduced and full integration. Three loading levels are considered; the first maintains strains within the elastic range, the second induces moderate plastic strains, and the third produces large deformations and large plastic strains.

scholarly journals Development of Finite Element Model for the Control of Solidification Shrinkage in Al-Si (A8011) Alloy Castings

2020 ◽  
Vol 4 (3) ◽  
Author(s):  
Olusanya Francis Dacosta ◽  
Samuel B Adejuyigbe ◽  
Bayode Olorunfemi ◽  
Adefemi Adekunle
Keyword(s):  
Finite Element ◽  
Finite Element Modelling ◽  
Research Work ◽  
Element Model ◽  
Temperature Profiles ◽  
Threshold Values ◽  
Governing Equations ◽  
Solidification Shrinkage ◽  
Element Modelling ◽  
Alloy Castings

The objective of this research work is to determine a realistic way of minimizing shrinkage in Aluminium-Silicon (Al-Si) alloy castings using finite element modelling. Finite Element method was used to discretize and solve the governing equations developed for the models using the commercial software, Comsol Multi-Physics. The models developed were validated from experimental data obtained from the foundry using six samples which were used to study the temperature profiles and nature of the solidification of the alloys. A comparison of the temperature profiles generated from the experiments and simulations show that in 64% of the processes, there were no significant differences between the experimental and simulated values. In comparing the Niyama values obtained from the experiments and those from the simulations, there were no significant differences in 46% of the processes. Threshold Niyama values of 0.143 (°C-s)1/2/mm was also established. Below these threshold values, it is predicted that shrinkage will occur in castings from these metals.Keywords— Aluminium alloy, Al-Si (A8011), Castings, Finite Element, Shrinkage, Solidification

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