BOUNDARY CONDITIONS IN FINITE ELEMENT MODELING OF STRATIFIED COASTAL CIRCULATION

1988 ◽  
Vol 1 (21) ◽  
pp. 190
Author(s):  
George C. Christodoulou ◽  
George D. Economou
Keyword(s):  
Finite Element ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Coastal Waters ◽  
Stratified Flow ◽  
Element Model ◽  
Numerical Computations ◽  
Element Modeling ◽  
Sponge Layer

The effect of boundary conditions on numerical computations of stratified flow in coastal waters is examined. Clamped, free radiation and sponge layer conditions are implemented in a two-layer finite element model and the results of simple tests in a two-layer stratified basin are presented.

Experimentally validated predictive finite element modeling of the V0-V100 probabilistic penetration response of a Kevlar fabric against a spherical projectile

2018 ◽  
Vol 9 (4) ◽  
pp. 504-524 ◽  
Author(s):  
Gaurav Nilakantan
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Ballistic Impact ◽  
Impact Testing ◽  
Woven Fabric ◽  
Projectile Impact ◽  
Element Modeling ◽  
The Impact

This work presents the first fully validated and predictive finite element modeling framework to generate the probabilistic penetration response of an aramid woven fabric subjected to ballistic impact. This response is defined by a V0-V100 curve that describes the probability of complete fabric penetration as a function of projectile impact velocity. The exemplar case considered in this article comprises a single-layer, fully clamped, plain-weave Kevlar fabric impacted at the center by a 0.22 cal spherical steel projectile. The fabric finite element model comprises individually modeled three-dimensional warp and fill yarns and is validated against the experimental material microstructure. Sources of statistical variability including yarn strength and modulus, inter-yarn friction, and precise projectile impact location are mapped into the finite element model. A series of impact simulations at varying projectile impact velocities is executed using LS-DYNA on the fabric models, each comprising unique mappings. The impact velocities and outcomes (penetration, non-penetration) are used to generate the numerical V0-V100 curve which is then validated against the experimental V0-V100 curve obtained from ballistic impact testing and shown to be in excellent agreement. The experimental data and its statistical analysis used for model input and validation, namely, the Kevlar yarn tensile strengths and moduli, inter-yarn friction, and fabric ballistic impact testing, are also reported.

scholarly journals Three-dimensional finite element modeling for evaluation of laryngomalacia severity in infants and children

2020 ◽  
Vol 48 (6) ◽  
pp. 030006052092640
Author(s):  
Hongming Xu ◽  
Jiali Chen ◽  
Shilei Pu ◽  
Xiaoyan Li
Keyword(s):  
Finite Element ◽  
Soft Tissue ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Three Dimensional ◽  
Element Model ◽  
3D Finite Element ◽  
Element Modeling ◽  
Laryngeal Cartilage ◽  
Computed Tomography Images

This study was performed to investigate the feasibility of using a three-dimensional (3D) finite element model for laryngomalacia severity assessment. We analyzed laryngeal computed tomography images of seven children with laryngomalacia using Mimics software. The gray threshold of different tissues was distinguishable, and a 3D visualization model and finite element model were constructed. The laryngeal structure parameters were defined. The peak von Mises stress (PVMS) value was obtained through laryngeal mechanical analysis. The PVMS values of the laryngeal soft tissue and cartilage scaffolds were independently correlated with disease severity. After stress loading the model, the relationship between laryngomalacia severity and the PVMS value was apparent. However, the PVMS value of laryngeal soft tissue was not correlated with laryngomalacia severity. This study established the efficacy of a finite element model to illustrate the morphological features of the laryngeal cavity in infants with laryngomalacia. However, further study is required before widespread application of 3D finite element modeling of laryngomalacia. PVMS values of the laryngeal cartilage scaffold might be useful for assessment of laryngomalacia severity. These findings support the notion that structural abnormalities of the laryngeal cartilage may manifest as quantifiable changes in stress variants of the supraglottic larynx.

Finite Element Simulation of Track Shoe and Ground Adhesion

2014 ◽  
Vol 644-650 ◽  
pp. 402-405
Author(s):  
Cong Bin Yang ◽  
Liang Gu ◽  
Qiang Li
Keyword(s):  
Finite Element ◽  
Constitutive Model ◽  
Boundary Conditions ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Finite Element Simulation ◽  
Element Model ◽  
Elastic Model ◽  
Element Simulation ◽  
Coulomb Model

Soil constitutive model was established based on elastic model and Mohr-Coulomb model. Simplified common form track shoe was determined for finite element modeling. Loading and boundary conditions were determined based on the actual driving conditions of the vehicle. Meshing was based tetrahedron. Finite element model was compared with experiment to verify the validity.

Patient Specific Finite Element Modeling of a Human Skull

2006 ◽  
Vol 49 ◽  
pp. 227-234 ◽  
Author(s):  
Norio Inou ◽  
Michihiko Koseki ◽  
Koutarou Maki
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Image Data ◽  
Element Model ◽  
Biomechanical Study ◽  
Modeling Method ◽  
Patient Specific ◽  
Human Skull ◽  
Element Modeling

This paper presents automated finite element modeling method and application to a biomechanical study. The modeling method produces a finite element model based on the multi-sliced image data adaptively controlling the element size according to complexity of local bony shape. The method realizes a compact and precise finite element model with a desired total number of nodal points. This paper challenges to apply this method to a human skull because of its intricate structure. To accomplish the application of the human skull, we analyze characteristics of bony shape for a mandible and a skull. Using the analytical results, we demonstrate that the proposed modeling method successfully generates a precise finite element model of the skull with fine structures.

Finite Element Modeling for Tap Design Improvement in Form Tapping

2005 ◽  
Vol 128 (1) ◽  
pp. 65-73 ◽  
Author(s):  
Curtis Warrington ◽  
Shiv Kapoor ◽  
Richard DeVor
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Design Parameters ◽  
Process Conditions ◽  
Design Improvement ◽  
Element Modeling ◽  
Form Tapping

The form tapping process typically yields unfinished threads known as split crests. Thread quality can be greatly improved by reducing the size and severity of split crest formation. This paper develops a finite element model to simulate form tapping with an eye towards the reduction of split crests. The model is validated against linear scratch experiments, and simulations are compared to actual tapping. The effects of various tap design parameters and tapping process conditions on the formation of split crests are investigated to strive toward an optimal tap design.

scholarly journals Analytical and Finite Element Modeling of the Dynamic Characteristics of a Linear Feeding Stage with Different Arrangements of Rolling Guides

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jyh-Cheng Chang ◽  
Jui-Pin Hung
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Dynamic Characteristics ◽  
Element Model ◽  
Linear Guide ◽  
Element Modeling ◽  
Positioning Stage ◽  
The Finite Element Model

This study was aimed at investigating the dynamic behaviors of the linear driven feeding stage by means of the analytical and finite element modeling approaches. To assess the dynamic characteristics of the stages with different linear guide arrangements, the finite element model of the stages was created, in which the linear components with rolling interface were accurately modeled based on the Hertzian theory. On the other hand, the analytically mathematical model was derived to determine how the linear guide arrangement affects the dynamic characteristics of the stage. Results of the modal analysis show that the vibration behaviors of the positioning stage are dominated by the rigidity of the linear components and the platform. In addition, comparisons of the results from the two approaches further indicate that the platform rigidity is an important factor determining the accuracy of the prediction of the vibration frequencies by the analytically mathematical model. As a conclusion of the study, the analytically mathematical model can approximate well to the finite element model when the linear stage is designed with appropriate structure rigidity.

Finite Element Modeling Method of 3D Braided Composites Based on ICT Technique

2012 ◽  
Vol 236-237 ◽  
pp. 16-20
Author(s):  
Shu Yong Wang ◽  
Jian Fu ◽  
Qian Li Wang
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Composite Materials ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Element Model ◽  
Braided Composites ◽  
Element Modeling ◽  
3D Braided Composites ◽  
The Finite Element Model

A finite element modeling method based on industrial computed tomography (ICT) technique is proposed to address the insufficient accuracy of traditional grinding method for the meso-structure analysis of composite materials. In this method, the slice images of 3D composites are first acquired by ICT technique. And then, the internal meso-structure images of composite materials are obtained through the digital image processing to the slice images. Finally the meso-structure images are converted to vector format and inputted ANSYS to build the finite element model for the analysis of the mechanical properties. The experimental results show that this method can establish the finite element model and reveal the internal structure and the inherent mechanical properties of composite materials. These researches provide a reference for the manufacture processing of 3D braided composites, and the theoretical basis for the optimal design and performance evaluation. It would be of significance for the improvement of the composites mechanical properties.

The Finite Element Modeling and Structure Analysis of Dust Removal Fan

2014 ◽  
Vol 1061-1062 ◽  
pp. 833-836
Author(s):  
Qian Peng Han ◽  
Bo Peng
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Structure Analysis ◽  
Element Model ◽  
Dust Removal ◽  
Element Modeling ◽  
Nature Frequency

This paper mainly discussed the process to create finite element model of Y4-68 fan,and also analysis the nature frequency and liner static stress.According to the analysis result to determine the optimized parameters,to prepare for the stage of optimization.

Finite Element Modeling of the Response of Long Floating Structures Under Harmonic Excitation

1985 ◽  
Vol 107 (1) ◽  
pp. 48-53 ◽  
Author(s):  
C. Georgiadis
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Finite Element Model ◽  
Finite Element Modeling ◽  
Wave Field ◽  
Element Model ◽  
Harmonic Excitation ◽  
Element Analysis ◽  
Floating Structures ◽  
Element Modeling

The response of long floating structures to a harmonic excitation is the basis for the response calculation in a short-crested wave field. This paper will present consistent formulas for obtaining the nodal loads in a finite element analysis. The accuracy of the method used is compared with the results obtained using a Rayleigh-Ritz approximation of the response with continuous eigenfunctions. The error of using an irrational finite element model is demonstrated for comparison, and to indicate to designers of similar structures the large effects which they may be overlooking.

Determining the Rayleigh damping parameters of flexible pavements for finite element modeling

2021 ◽  
pp. 107754632110267
Author(s):  
Jiandong Huang ◽  
Xin Li ◽  
Jia Zhang ◽  
Yuantian Sun ◽  
Jiaolong Ren
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Natural Frequencies ◽  
Least Squares Method ◽  
Element Model ◽  
Beam Model ◽  
Element Modeling ◽  
Rayleigh Damping ◽  
Damping Matrix

The dynamic analysis has been successfully used to predict the pavement response based on the finite element modeling, during which the stiffness and mass matrices have been established well, whereas the method to determine the damping matrix based on Rayleigh damping is still under development. This article presents a novel method to determine the two parameters of the Rayleigh damping for dynamic modeling in pavement engineering. Based on the idealized shear beam model, a more reasonable method to calculate natural frequencies of different layers is proposed, by which the global damping matrix of the road pavement can be assembled. The least squares method is simplified and used to calculate the frequency-independent damping. The best-fit Rayleigh damping is obtained by only determining the natural frequencies of the two modal. Finite element model and in-situ field test subjected by the same falling weight deflectometer pulse loads are performed to validate the accuracy of this method. Good agreements are noted between simulation and field in-situ results demonstrating that this method can provide a more accurate approach for future finite element modeling and back-calculation.

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