Mechanical Engineering Commons^™

Evaluation Of Numerical Inversion Of Laplace Transformed Solutions, Yu-Chwin Lin

Theses

Here, some linear physical systems are analyzed by using the standard Numerical Laplace Transformation and Inversion method, including undamped and damped systems:

1. Undamped system: A bar clamped at one end and at one end free.

2. Damped system: Viscously damped linear discrete system.

The advantage of the Numerical Laplace Transformation method is that it reduces the inversion of the Laplace transformed solution to numerical integration; it makes the problem much easier to solve. In the present work, we also studied a new Numerical Laplace Transformation Inversion method by Wilcox (App.0 and Ref.l). The merit of this new method is …

Analyze3d, A Structural Analysis Program Employing Membrane And Solid Finite Elements, James Mendham Gathercole

Theses

The purpose of this thesis is to describe the addition of an 8 and 20-node isoparametric brick element to the finite element program ANALYZE, permitting three-dimensional analysis. The reason for the addition is that even though Analyze is a relatively simple program, its simplicity makes it a good educational tool for finite element courses. The added brick element expands the use of the program for educational purposes.

In its original form, Analyze is a finite element package for static structural analysis developed at Wright Patterson Air Force Base. The program consists of four finite elements: (1) bar, (2) membrane triangle, …

Theoretical Investigation Of Submerged Turbulent Jet, Talal N. Hindi

Theses

A theoretical investigation concerning the flow characteristics velocity distribution of a circular submerged turbulent axisymetricic water jet impinging on a flat plate was carried out. Starting with the use of the available data and equations obtained by previous investigators and found room for improvement. By solving these equations for the velocity distribution and comparing them to the experimental results is was found out where improvements of the analysis were were necessary. Then taking Tollwien's solution for the velocity distribution and changing the reference axis to see whether or not the equations would give better results for velocity calculations. With certain …

A Tracheoesophageal Puncture Voice Prosthesis, Georghios Makris

Theses

A voice prosthesis was developed that allows verbal communication of laryngectomised patients. The prosthesis requires a superiorly directed tracheoesophageal puncture in which the periscope mounted on the tracheal stoma vent is introduced. The prosthesis is operated by air injection through the periscope. Air injection is achieved by pulmonary pressure after the occlusion of the stoma vent. Stoma vent occlusion can be achieved either by the patient's finger or by the designed cover valve mounted on the prosthesis. The cover valve allows free breathing, hand-free prosthesis use, and it can release excess pressure during coughing. Periscope valve air resistance tests have …

Modal Analysis Of A Cantilever Plate, Ohseop Song

Theses

This thesis discusses the vibration of a thin, flat cantilever aluminum plate. Results are based on both an analytical finite element method using the ANSYS program and an experimental analysis using a digital Fast Fourier Transform (FFT) analyzer. The FFT analyzer permits extraction of modal parameters (natural frequency, damping, mode shape) for the plate.

Substructuring Analysis For Impact Dynamics Using Ansys Finite Element Package, Chang Ho Cho

Theses

This thesis is intended to serve as an introductory guide to ANSYS finite element package for the analysis of impact dynamics. Substructuring technique has been used to reduce the degrees of freedom.

Finite element method is essentially a numerical technique to calculate elastic deformations. However, by introducing some techniques like gap element, the technique can be easily extended to rigid body dynamic analysis. To solve the equation of motion both for rigid body and elastic deformations, direct integration technique is used in this thesis, i.e., Houbolt method.

ANSYS is a large scale general purpose computer program for finite element analysis. …

Circular Plate Analysis Using Finite Element Method, Shyh-Rong Chiu

Theses

The ANSYS computer program is the application of finite element methods to large-scale engineering problems. In this work the ANSYS program has been employed to solve the circular plate under uniformly loaded with various boundary conditions as follows: (1) clamped along entire edge, (2) simply supported along entire edge, (3) clamped at several points along the boundary, (4) simply supported at several points along the boundary, and (5) simply supported 36 points with 4 points clamped..

The results obtained from the ANSYS program illustrated that the finite element method has no boundary conditions constraints and presents good approximations to the …

Introductory Guide To Bridgeport Series I Cnc Milling, Drilling And Boring Machine, Apurva Vinodchandra Doshi

Theses

This thesis is intended to serve as an easy introductory guide on how to work with Bridgeport Series I CNC Milling, Drilling and Boring machine. An attempt has been made to make the subject matter simpler to give the reader a good start in programming and operating this machine

The spectrum of technological implementation of CNC machine tools is extremely broad,. Companies utilizing advanced technologies such as computer graphics, DNC and Group Technology are in this field for some time. Even small shops are getting equipped with CNC machine tools. The present CNC systems, which are less costly, more reliable …

Pressure Drop In A Strainer Element By The Finite Element Method, Wei-Long Chen

Theses

The pressure drop in a strainer element which consists of a channel and a diffuser has been investigated by the finite element method and the semi-empirical analysis.

An existing finite element program, FEM2D using the penalty parameter model, was employed. It was found that the range of Reynolds numbers in the strainer element was 0.193 to 4.824. For the pressure drop in the channel, the finite element method is in agreement with the analytical solution. For flow in the diffuser, the finite element method failed to give satisfactory results due to flow separation.

A Closed Form Image Force Function For Deposition Of Particles In A Cylindrical Tube, Hsi-Chung Chiou

Theses

This study investigated the behavior of charged particles suspended in a laminar steady incompressible flow in a cylindrical tube under the influences of image , inertia , viscous and gravitational forces. A new expression for the image force was obtained by introducing an approximate potential energy function. The velocity profiles employed in the analysis were uniform and parabolic.

The governing equations derived were based on Newton's second law of motion and were solved by a Runge-Kutta numerical method. The results were obtained for different values of Q, a dimensionless inertia-charge parameter. For a value of Q equal to zero the …

On Torsional Spring Constants At The Juncture Of Piping-Nozzle, Shean-Juinn Chiou

Theses

Numerical results of torsional spring constants at the juncture of piping-nozzle are studied in this thesis by using the "ANSYS" program and run on VAX computer. These results are presented in tabulated form for a piping-nozzle vessel with constant thickness of 0.375 in. Plot for the torsional spring constants in terms of beta (nozzle radius/pipe radius), gamma (pipe radius/thickness) and alpha (pipe length/radius) are also presented in this thesis. These data are under zero piping internal pressure with beta ranging from 0.1 to 0.8, and gamma ranging from 10 to 150. A numerical example with verification is also given.

Thermal Energy Storage Using Phase Change Material With Multi - Melting Temperatures, Christakis Christodoulou

Theses

Three different models are developed in this investigation, for the study of thermal energy storage, using a phase change material with multi-melting temperatures. Using Model B as the basis, the developed partial differential equations are numerically solved by a finite difference method. Two computer programs were written based on that solution, one for the charging mode and one for discharging. Finally, using the computer programs, a set of results was obtained for both charging and discharging, utilizing calcium chloride hexahydrate as the phase change material with constant and multi-melting temperatures.

Isoparametric Finite Elements For Axisymmetric Solids, Ramanand R. Shetty

Theses

The finite element formulation of axisymmetric plane stress analysis is used to develop a computer program for numerical implementation. The basic relations used to derive the finite element equations for a solid continum are reviewed in the thesis. The programming organization is summarized and program list is given in Appendix.

The program portion for isoparametric elements are borrowed from Numerical Methods in Finite Element Analysis by K. J. Bathe and E. L. Wilson, and various other subroutines are used from Mr. Huang's thesis on Micropolar elasticity analysis. Mr. Huang's computer program is based on the work done by Dr. Nakamura …

On Radial And Rotational Spring Constants Of Piping With Square Tubing Attachment, Hson-Chih Sun

Theses

Numerical values and analytical expressions for spring constant in the radial direction, and rotational spring constants in the circumferential and longitudinal directions of piping with square structural tubing attachment are presented.

Following Bijlaard's approach, the double Fourier series solution for the thin shell equation are used to express these spring constants as a function of internal pressure, q, and pipe-structural tubing parameters, such as alpha (piping length/radius), beta (tube size/pipe dia.), gamma (pipe radius/thickness) and thickness of the structural tubing. Numerical results of these spring constants are presented in tabulated form. These Tables include a set of eight standard square …

The Stress Distribution Of The Frp Pressure Vessel By Using Ansys Program, Lung-John Tsai

Theses

The objective of this paper is to take advantage of a general purpose finite element computer program, called ANSYS, to analyze the surface stress distribution of a fiber reinforced plastic (FRP) laminated composite pressure vessel. The vessel is subjected to internal pressure, which is assumed to be constant over the interior surfaces.

In this paper, the material is assumed to be orthotropic, and the stress-strain relationship linear.

A FRP pressure vessel subjected to an Internal pressure, 6.895 MPa (1000 psi), is taken as an example. The results show that this approach compares well with a theoretical solution.

Plate Stress Analysis By The Finite Element Method, Wen-Jung Chuang

Theses

The finite element formulation of plate elasticity is presented and is employed in the development of the formulation of element stiffness equations. The programming structures are also summarized.

The finite element program PLATE cited from Prof. J. N. Reddy's " An Introduction to the Finite Element Method " has been used to solve the plate bending problems with quadrilateral elements. The problems solved are:

(1) deflections and stresses in a circular plate with all edges simply supported under uniform load.

(2) deflections and stresses in a circular plate with all edges clamped under uniform load.

each case including four different …

An Analysis Of Different Desalination Processes, Vahe Garabed Hovsepian

Theses

The object of this thesis is to study the various modes of desalination and analyze the energy and economic requirements. The desalination methods discussed are, single stage desalination, Long tube vertical Evaporator, Multistage Flash distillation, Solar Energy method, Freezing method, Reverse osmosis & Electrodialysis.

It was found that for vapor reheat process at 350°F input 639 ft-lbs/lb product required 2.01 kw-hr/100gal. product and the total cost 51.6c/1000gal.

Not one process is best for everyone. In countries close to the equator, the solar energy method is the best. Most other countries depend on flash distillation process, etc. So we can't draw …

Computational Method For Robot Manipulator Dynamics Based On The Gibbs-Appell Equations, Kwang Bok Kim

Theses

Industrial robots are open-loop multi-degree of freedom mechanisms whose dynamic characteristics are described by nonlinear differential equations. The computations of forces and torques required at each joint of robot manipulator are crucial step for real time control of robot manipulators.

Vukobratovic developed a new computational method for rigid body articulated open-loop mechanisms based on the Gibbs -Appell equations to generate differential equations of motion for spatial open - chain mechanisms. To solve these equations, he introduced the recursive kinematic transformation matrices that represent the motion of each linkage with respect to the base linkage.

Computer programs are developed in this …

Laminar Flow In A Porous Pipe With One Plugged End, Pyne-Hwa Ku

Theses

A steady laminar flow through a co-cylinder porous pipe with one plugged end was investigated theoretically to obtain velocity, pressure and shear stress distributions.

An integral momentum equation and the Darcy's law for flow through the porous wall were solved numerically by the Runge-kutta method.

As the fluid is injected from the outer wall into the porous tube, the fluid in the inner tube is accelerated from rest at the plugged end to a fully-developed velocity profile at the exit of the porous tube. It was found that the coefficient of the wall shear stress and the dimensionless pressure drop …

Stress Analysis Of A Pressure Vessel By The Finite Element Method, Hsin-Te Liao

Theses

The objective of this paper is to take a finite element program, called ANSYS, to analyze the surface stress distribution of a thin-wall pressure vessel with a spherical head.

The computer program ANSYS, which primarily applies the principle of virtual work in solid continuum, has been used to solve shell problems with quadrilateral element. Problems solved are: <1> hoop stress <2> meridional stress (<)3) maximum shear stress.

In this paper, the theoretical finite element formulation of axisymmetric elasticity of the ANSYS program is presented.

Finally, some numerical examples of shells with spherical heads of various radius are given. The solution obtained from ANSYS is very …

Discontinuity Stresses Analysis In Pressure Vessel, Jan-Joo Liu

Theses

In this paper, the ANSYS general purpose finite element computer aided design program was used to perform a series of stress analyses for shells with heads of various shapes.

The analysis included maximum discontinuity stresses, stress contours and displacements induced in axisymmetrical shells subjected to internal pressure loading; especially at the junction of the cylinder and heads of various shapes.

CONICAL SHELL finite elements and TWO-DIMENSIONAL ISOPARAMETRIC finite elements were used in the analysis. The results of the analyses compared very favorably with solutions derived from membrane and bending theory solutions for pressure vessels.

The effect of longitudinal and hoop …

Chebyshev Approximate Solution For Stiff Problems, Kwo-En Hoh

Theses

Chebyshev polynomial and collocation methods are adapted to solve general ordinary differential equations ( initial-value problems and boundary-value problems ). Approximate solutions of initial-value problems are obtained in step-by-step fasion. the solutions have minimax absolute error in the interval and correct values at the end points. The approximate solutions of boundary-value problem will be continuous on the whole domain and have piecewise Chebyshev approximation characteristics in each subinterval of the chosen partition.

Implementation Of Finite Element Method On A Microcomputer, Chi-Yuang Huang

Theses

A finite-element program FEM2D has been implemented on a PHILIPS microcomputer. The program has a generation preprocessor and thus makes finite-element analysis on a microcomputer considerably easier than before, since it allows models to be created and edited much faster than by manual method. The interactive program FEM2D prompts the user to input data directly from the screen. It is convenient for the user, both in teaching and learning.

The FEM2D is a two-dimensional finite-element program capable of solving two-dimensional problems, such as plane elasticity, heat transfer and imcompressible fluid flow problems. It is developed with a formulation of a …

Deposition Of Suspensions In Convergent Channels Due To Electrostatic Image Forces, Kwok Wah Hui

Dissertations

The deposition of suspensions for uniform flow in convergent channels under the combined influences of inertia, viscous and electrostatic image forces was studied theorectically. The fluid phase was assumed to be two-dimensional, steady, uniform, incompressible and laminar while the particle phase was assumed to be uniform, steady, dilute and with negligible gravity effects.

Since the image force equations for convergent channels have not been derived, it becomes one of the main purposes of this study to perform the derivation of the image force equations. The lengths of the channels were chosen in a way that the exit area is only …

Deposition Of Particles In Tubes Due To Gravity And Electrostatic Charges, Win-Chung Chen

Dissertations

The deposition of particles in a parallel-plate channel and a circular tube under the influence of inertia, fluid viscosity, gravity and electrostatic image forces was studied by analytical and numerical methods. A laminar flow with uniform and parabolic velocity profiles was investigated with a particle initial velocity of zero as well as that of the local fluid velocity.

The governing equations were solved by the Lagrangian approach to obtain the particle trajectories from which the fraction of deposition was calculated. Closed form solutions for particle trajectory and a complete deposition of particles in a finite length of the flow passage …

Computer Aided Stress Analysis Of Long Bones Utilizing Computed Tomography, Shlomo Asher Marom

Dissertations

A computer aided analysis method, utilizing computed tomography (CT) has been developed, which together with a finite element program determines the stress-displacement pattern in a long bone section. The CT data file provides the geometry, the density and the material properties for the generated finite element model.

A three-dimensional finite element model of a tibial shaft is automatically generated from the CT file by a pre-processing procedure for a finite element program. The developed pre-processor includes an edge detection algorithm which determines the boundaries of the reconstructed cross-sectional images of the scanned bone. A mesh generation procedure then automatically generates …

Two And Three-Dimensional Isoparametric Finite Elements For Axisymmetric Micropolar Elasticity, Fuang-Yuan Huang

Dissertations

Finite element analysis program for isotropic and orthotropic axisymmetric micropolar (Cosserat) elastic solids are developed in this thesis. Isoparametric elements of 8- and 20- node are used to solve general three-dimensional problems, arid both 4- and 8-node elements are used for two-dimensional cases. Three-dimensional finite element formulation for cylindrical coordinate system is derived. Corresponding Fortran programs are then developed. Patch tests are performed for two-dimensional cases to verify the applicability of the finite element method to non-rectangular geometries. Several two-dimensional and three- dimensional problems for micropolar elastic solids are solved to verify the formulations arid computer program.

Good agreements were …

Simulation Of A Microprocessor Controlled Drill Press, Arun J. Ayyagari

Theses

The concept of flexible manufacturing systems has ushered new dimensions into machine tool design. The power of this new technique is that a high degree of flexibility in a machine tool can be easily achieved by developing a software based control system as against conventional hard wired systems in existence.

To demonstrate this point, a microprocessor based control system is developed, in this thesis, to control the automated drill press. The Motorola MC6808 8-bit microprocessor is chosen as an example.

The microprocessor first evaluates the optimum cutting parameters for the given cutter size, work material and operation. It then uses …

Computational Method For Solving The Kinematics Of Mechanisms Using Matrix Methods, Rajat Pardal

Theses

This thesis deals with the computational methods for kinematics of mechanisms using matrix methods. The method is particularly suited to the complex mechanism problems for which hand calculations are difficult. The thesis first reviews the matrix methods on which the program IMP is based. A computer program developed by Ve Tung using the same theory is enhanced in this thesis. By using this revised program, comparison between the non-linear algebraic approach and the matrix methods developed in this thesis has been made by the help of suitable examples. Further, it has been proved that the Integrated Mechanisms Program does not …

Finite Element Analysis Of The Prosthetic Acetabular Region, Katkuri Venkat Rammanohar Reddy

Theses

Femoral component loosening and prosthetic stem fractures have renewed interest in conservative alternatives to conventional total hip replacements. The objective in this study is to get interfacial stresses of a acetabular surface replacement cup. This is done by performing finite element analysis of the model. A solid three - dimensional model with a grid of 3D isoparametric solid elements is generated using ANSYS, a powerful finite element analysis package. The stiffness is considered to be linearly proportional to the stress in the acetabular region. The stresses are determined by performing iterative finite element analysis. Stresses arp computed using two different …