Step Coverage Modeling of Thin Films Deposited by CVD Using Finite Element Method

1991 ◽  
Vol 250 ◽  
Author(s):  
Ching-Yi Tsai ◽  
Seshu B. Desu
Keyword(s):  
Finite Element ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Element Model ◽  
Number Ratio ◽  
Step Coverage ◽  
Model Predictions ◽  
Dimensional Finite Element ◽  
Deposition Processes ◽  
Good Agreement

AbstractA two—dimensional finite element model was developed to study the step coverage of submicron trenches with arbitrary shape under chemical vapor deposition processes. Parameters that characterize the step coverage were found to be the surface Damkohler number, ratio of diffusion coefficients inside and outside of the trench, and aspect ratio of the trench geometry. Efforts were concentrated on studying the step coverage of SiO2 film deposited from SiH4/O2 precursors within rectangular shape trenches. The model predictions were found to be in good agreement with reported experimental results.

Rigid-Plastic Impact of Single Angular Particles

2021 ◽  
Author(s):  
Sandeep Dhar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Orientation Dependence ◽  
Particle Orientation ◽  
Rigid Plastic ◽  
Plastic Model ◽  
Model Predictions ◽  
Good Agreement ◽  
Angular Particles

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.

Finite Element Model of a Heated Wire Catalyst in Cross Flow

2008 ◽  
Author(s):  
Katie Leichliter ◽  
Bob Lounsbury ◽  
Judi Steciak ◽  
Ralph Budwig ◽  
Steve Beyerlein
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Cross Flow ◽  
Element Model ◽  
Trailing Edges ◽  
Dimensional Finite Element ◽  
Fuel Mixtures ◽  
Three Dimensional Finite Element ◽  
Calculated Average ◽  
Good Agreement

Experimentally obtained temperatures of a heated coiled platinum wire in low Reynolds Number cross-flow were compared with a three-dimensional finite element (finite volume) model. The calculated average wire temperature was in good agreement with experimentally obtained values with deviations close to experimental uncertainty bounds at temperatures between 530K and 815K. The model predicted a temperature variation along each coil, with the lowest temperatures along the leading edges of the coil and the higher temperatures at the trailing edges. The rate of heat generated at the wire surface from catalytic reactions was found for the ignition of lean propane/oxygen/nitrogen mixtures. We studied the coiled catalytic wire as part of our efforts to ignite very lean homogeneous air-fuel mixtures in transportation engines under conditions approaching Homogeneous Charge Compression Ignition (HCCI).

Simulation of Step Coverage in Chemical Vapor Deposition Processes

1991 ◽  
Vol 138 (8) ◽  
pp. 2466-2468 ◽  
Author(s):  
K. ‐W. Schröder ◽  
J. Schlote ◽  
S. Hinrich
Keyword(s):  
Chemical Vapor Deposition ◽  
Vapor Deposition ◽  
Chemical Vapor ◽  
Step Coverage ◽  
Deposition Processes

Finite Element Modeling of Shear-Slitting Process

2012 ◽  
Vol 459 ◽  
pp. 3-6 ◽  
Author(s):  
Mang Ding ◽  
Di Ping Wu ◽  
Qin Qin
Keyword(s):  
Finite Element ◽  
Metal Cutting ◽  
Shear Failure ◽  
Element Model ◽  
Failure Criteria ◽  
Mass Scaling ◽  
Dimensional Finite Element ◽  
Material Separation ◽  
Sheet Metal Cutting ◽  
Good Agreement

Shear-slitting is a sheet metal cutting process used for dividing coiled sheet into narrower coils. In this paper, a two-dimensional finite element model was developed for the calculation of the shear-slitting process by using ABAQUS/Explicit. The shear failure criteria and the element-delete method were adopted to model the material separation. Mass scaling was used to reduce the solution time. The effect of clearance on the burr height was investigated. The simulation results show good agreement with experimental results. The critical clearance values was suggested for decreasing the burr.

Effective Parameters on Elastic Modulus of Polymer/Clay Nanocomposites

2011 ◽  
Vol 403-408 ◽  
pp. 4416-4420 ◽  
Author(s):  
M. Saadatfar ◽  
A. Soleimani
Keyword(s):  
Experimental Data ◽  
Finite Element ◽  
Elastic Modulus ◽  
Element Model ◽  
Clay Nanocomposites ◽  
Two Dimensional ◽  
Effective Parameters ◽  
Polymer Clay Nanocomposite ◽  
Dimensional Finite Element ◽  
Good Agreement

In this work a two dimensional finite element model is developed to simulate the fully exfoliated Polymer/Clay nanocomposite behavior and evaluate its’ elastic modulus. The influence of elastic moduls of matrix and clay on the elastic modulus of exfoliated Nylon 66 /clay nanocomposite is investigated with the aid of numerical simulations. Results show good agreement with experimental data from literature.

scholarly journals Rigid-Plastic Impact of Single Angular Particles

2021 ◽  
Author(s):  
Sandeep Dhar
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Element Model ◽  
Orientation Dependence ◽  
Particle Orientation ◽  
Rigid Plastic ◽  
Plastic Model ◽  
Model Predictions ◽  
Good Agreement ◽  
Angular Particles

The trajectory of an angular particle as it cuts a ductile target is, in general, complicated because of its dependence not only on particle shape, but also on particle orientation at the initial instant of impact. This orientation dependence has also made experimental measurement of impact parameters of single angular particles very difficult, resulting in a relatively small amount of available experimental data in the literature. The current work is focused on obtaining measurements of particle kinematics for comparison to rigid plastic model developed by Papini and Spelt. Fundamental mechanisms of material removal are identified, and measurements of rebound parameters and corresponding crater dimensions of single hardened steel particles launched against flat aluminium alloy targets are presented. Also a 2-D finite element model is developed and a dynamic analysis is performed to predict the erosion mechanism. Overall, a good agreement was found among the experimental results, rigid-plastic model predictions and finite element model predictions.

A Finite Element Analysis of Stress Fields in Vickers Indentation on Brittle Materials

2007 ◽  
Vol 329 ◽  
pp. 403-408 ◽  
Author(s):  
Bing Zhang ◽  
Masato Yoshioka
Keyword(s):  
Finite Element ◽  
Three Dimensional ◽  
Brittle Materials ◽  
Element Model ◽  
Time Dependent ◽  
Stress Fields ◽  
Element Analysis ◽  
Dimensional Finite Element ◽  
Three Dimensional Finite Element ◽  
Good Agreement

A three dimensional finite element model for Vickers indentations on brittle materials is presented in order to analyze the stress distribution. The objective of this paper is to study when and where cracks are most likely to initiate and propagate in the indentation cycle based on the analyzed stresses. Therefore the time-dependent stresses around and below the surface of the contact area during the indentation cycle, especially at the end of loading and at the beginning of unloading phase are investigated in detail. The analytical results are shown to be in good agreement and verified with the experimental results.

Modelling the load–slip behaviour of timber joints with mechanical fasteners

1991 ◽  
Vol 18 (4) ◽  
pp. 607-616 ◽  
Author(s):  
M. A. Erki
Keyword(s):  
Finite Element ◽  
Joint Interface ◽  
Limit States ◽  
Finite Element Approximations ◽  
Axial Tension ◽  
Interface Characteristics ◽  
Model Predictions ◽  
Dimensional Finite Element ◽  
Timber Joints ◽  
Good Agreement

An analytical model of behaviour is presented, which uses one-dimensional finite element approximations to predict the short-term load – slip response of a single fastener joint. The model treats the elastoplastic behaviour of the fastener as well as the nonlinear, nonelastic properties of the wood. It accounts for some of the distinctive behaviour of timber joints such as fastener withdrawal, rotational restraint at the fastener ends, joint interface characteristics, and combined fastener bending and axial tension. Good agreement is obtained between model predictions and test behaviour for single fastener glulam rivet, nail, and bolt joints. The model can be adapted to include the variability in wood and fastener properties, and can be incorporated into a large number of computer simulations in order to predict the fifth fractiles of the populations of joint resistances, which can be used in a limit states design approach. Key words: timber structures, glulam rivet connections, nailed connections, bolted connections, mathematical model, finite element, nonlinear analysis.

Numerical Simulation of Bolted-Steel Plates Strengthened Coupling Beams

2010 ◽  
Vol 163-167 ◽  
pp. 3677-3681
Author(s):  
Yong Zhu ◽  
Yun Zhou ◽  
He Zhu
Keyword(s):  
Finite Element ◽  
Reinforced Concrete ◽  
Element Model ◽  
Steel Plates ◽  
Nonlinear Finite Element Method ◽  
Analysis Model ◽  
Coupling Beams ◽  
Dimensional Finite Element ◽  
Special Ring ◽  
Good Agreement

One reinforced concrete coupling beam and two strengthened reinforced concrete coupling beams by bolted steel plates are analyzed by nonlinear finite element method. Two-dimensional finite element model is employed with material nonlinearities and geometrical nonlinearities. A special ring region, which simulates the slip effect between concrete and steel plates, is developed an incorporated into the numerical analysis model. The load-displacement relationship, cracking/crushing type and steel plates internal are compared and found to be in good agreement with those in test.

Finite Element Analysis of Nonuniformity of Tires with Imperfections5

2007 ◽  
Vol 35 (3) ◽  
pp. 226-238 ◽  
Author(s):  
K. M. Jeong ◽  
K. W. Kim ◽  
H. G. Beom ◽  
J. U. Park
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Three Dimensional ◽  
Element Model ◽  
Radial Force ◽  
Element Analysis ◽  
The Finite Element Analysis ◽  
Dimensional Finite Element ◽  
Force Variation ◽  
Three Dimensional Finite Element

Abstract The effects of variations in stiffness and geometry on the nonuniformity of tires are investigated by using the finite element analysis. In order to evaluate tire uniformity, a three-dimensional finite element model of the tire with imperfections is developed. This paper considers how imperfections, such as variations in stiffness or geometry and run-out, contribute to detrimental effects on tire nonuniformity. It is found that the radial force variation of a tire with imperfections depends strongly on the geometrical variations of the tire.

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