Engineering Commons^™

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.

An 8052 Ah - Basic, Based Development System, Suresh Vishwanath Leley

Theses

This project exploits the latest in microcontrollers-an entire environment for developing and prototyping a microcontroller application. With one key chip, a little glue, and a Dumb terminal a powerful system is achieved at a vanishingly small cost. This "one chip" system is adequate for realizing a wide range of applications calling for a small computer or an embedded processor.

Besides economy of system cost, the turn around time from concept to functioning application can be extremely short, even when the development engineer is not particularly well acquainted with traditional assembly language and microprocessor development practices. This economy is achieved by …

An Analysis Of Minimum Shift Keying From The Viewpoints Of Quadrature Multiplexed And Multi-H Continuous Phase Modulation Signaling, Alfred Anthony De Seta

Theses

Minimum Shift Keying (MSK) is a bandwidth efficient modulation scheme which offers superior performance over Quadrature Phase Shift Keying (QPSK) and Offset Quadrature Phase Shift Keying (OQPSK). This paper discusses these modulation techniques from a quadrature multiplexed signaling viewpoint and compares them in terms of error performance, bandwidth properties and bandlimiting and hardlimiting effects. MSK is also considered as a special case of a multi-h Continuous Phase Modulation (CPM) signal and the Viterbi algorithm is presented as an optimal detection scheme for this class of signals. A computer simulation is performed with the VA as the detection mechanism for an …

A Computer Aided Manufacturing System For Small Quantity Prototype Board Production, Santiago Garcia-Perez

Theses

A matrix addressed manufacturing tool has been built, tested, and integrated in a system aimed to exploit wire-wrap wiring technology for protoboard production in small quantities. Extensive software exploits the power and economy of the personal computer as a superb manufacturing tool and documentation system. Computer graphics are used as a visual aid that takes advantage of the cognitive capabilities of the human mind and eliminates the boredom and high costs involved with heavy automation achieving instead a tolerable level of human engagement with significantly increased efficiency. The approach presented is new and delivers substantial gains in productivity. The software …

Modelling Of Pile Load Tests In Weak Rock, Daniel Walter Caruso

Theses

The purpose of this thesis was to investigate the loss of load capacity of relaxed pile groups driven into weak bedrock. This was accomplished in the laboratory using a dynamic driving apparatus equipped with a static load testing system. The static load testing system applied loads hydraulically, and the load settlement behavior was monitored using an electronic load cell and a linear variable differential transducer (LVDT).

Tests were performed using 1" diameter steel pipe piles driven in a five pile group pattern at spacings of two diameters and four diameters. Piles were driven into a simulated rock mass consisting of …

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.

Realization And Implementation Of A Recursive Digital Convolution Algorithm In Cmos, Lik Tang Cheng

Theses

This thesis describes the implementation of a digital convolver. A recursive digital convolution algorithm was realised and implemented by using CMOS circuitry. This thesis also gives a technical overview of current CMOS processing technologies as well as various novel CMOS logic circuit techniques.

Design And Applications Of A Graphics Package For The Hp1000 Computer., Hsiao-Chih George Lee

Electronic Theses and Dissertations

The objective of this thesis is to develop the FORTRAN subroutine PLOTER which is a general-purpose plotting tool to plot charts on a Hewlett Packard plotter. The programs RESP and INVLAP which can plot the frequency and time responses of system functions are modified to adopt the PLOTER subroutine and are stored of the HP1000-A900 minicomputer whose software, the GRAPHICS/1000, supports the graphics ability of PLOTER. This thesis describes the theories, functions, software techniques and operations of the PLOTER subroutine and the application programs RESP and the INVLAP. It also provides program listings and example plots.

Aerating Butterfly Valves To Suppress Cavitation, R. Ted Davis

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Proper aeration of cavitating hydraulic equipment can greatly reduce cavitation intensity, noise, and damage. This thesis quantifies the benefit, in terms of damage and noise, from aerating six inch butterfly valve. The incipient damage level of cavitation was obtained for both aerated and non-aerated conditions. The level is defined as one pit per square inch of a soft aluminum test specimen per one minute of operation. A description of the cavitation pits that occurred plus where they appeared is presented. A graph showing the aerated and non-aerated limits of incipient damage is given along with a table showing the percent …

Analysis Of Compliant Pins Subjected To Plastic Deformation, Lincoln Miller

Theses

An experimental/numerical analysis of two types of compliant pins is presented: dynamic retention pins and cantilever pins. It is shown that there is a trade-off between the performances of both types of pins. For the same range of retention force, the cantilever pin, with a smaller stiffness, is more forgiving and gives a broader range of deflection. The dynamic retention pin is shown to be more reliable with time and replacement frequency, since it exhibits less plastic deformation for the same range of retention force.

Clostridium Perfringens: An Adjunctive Indicator In Nonpoint Pollution, Steven G. Eberl

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Clostridium perfringens (CP) was evaluated as an additional indicator in assessing impacts and sources of microbial pollution in the Idaho-Utah Cache Valley. Point, nonpoint, river water, and animal fecal samples were analyzed for CP, total coliforms, fecal collforms, and fecal streptococci.

Monthly river samples consistently contained < 20 CP/100 mL, but concentrations of the other indicators varied significantly by location and date. Two sample stations consistently had CP concentrations greater than 20/100 mL. One of these stations was influenced by an upstream wastewater discharge. Chlorinated effluent from this trickling filter plant contained greater than 10³ CP/100 mL, but met a 400 FC/100 mL discharge standard. A consistent decrease in CP concentrations in samples taken downstream from this wastewater source were found, despite significant impact from adjacent nonpoint pollution. Lagoon and oxidation ditch wastewater effluents sampled contained < 20 CP/100 mL.

Nonpoint sources sampled (e.g., cattle feedlot runoff) contained < 20 CP/100 mL and 10²-10⁴/100 …

The Vertical Distribution Of Salts In A Soil Profile During The Drainage Process, Adel Taha Yassin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to develop a model to predict water extraction patterns and therefore salt distribution patterns in a one dimensional homogeneous soil profile for a specified root distribution.

Water extraction was simulated as a function of the total potential and the root density at any level of the profile.

Salt redistribution caused by irrigation was simulated by assuming a partial and proportional displacement of the water in each soil layer.

A computer program was written for the model in Fortran language and implemented on the Vax. To evaluate the performance of the model, test studies were …

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 …

Reactions Of Chlorocarbon Species With Hydrogen Over Palladium On Alumina Catalyst And Zeolite Catalyst-Development Of Deactivation Models, Yuh-Der Yang

Dissertations

Four catalytic dechlorination reactions were studied experimentally using a fixed-bed reactor at atmosphere pressure. Reaction mechanisms were proposed, and the kinetics modelled.

The first reaction is 1,2-dichloroethane with hydrogen over zeolite catalyst. Catalyst deactivation models were examined.

The second reaction was between 1,2-dichloroethane and hydrogen over palladium catalyst on alumina support. Formation of two intermediates on the catalyst surface is proposed, which then produced ethane, ethylene, and ethyl chloride. Higher conversion to ethane and ethylene was observed at temperatures above 218°C while conversion to chloroethane is higher at temperatures below 218°C. The activation energy was found to be 15 Kcal/gm-mole. …

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 …

Free-Form Deformations In A Constructive Solid Geometry Modeling System, Scott R. Parry

Theses and Dissertations

No one will question that computers are revolutionizing the design industry. It is pointed out in [Bezier84] that before CAD/CAM, a surface was defined by tracing cross sections on a drawing and then carving these sections in wood, plastic or metal. The final model was determined by someone interpolating between the sections. This labor intensive art is being replaced by techniques of computer aided geometric design.

A Non-Linear Vortex Panel Method For Wings With Edge Separation, Vijay Kalburgi

Mechanical & Aerospace Engineering Theses & Dissertations

A global nodal vortex panel method is developed to predict steady aerodynamic loads on rectangular lifting surfaces with side edge separation. The lifting surface and free shear layers are modeled by bound and free vortex sheets respectively, which are then discretized into triangular bound and free vortex panels respectively. On each triangular panel, a linear distribution of vorticity is defined in terms of the global components of vorticity at its nodes. The velocity field induced by any triangular vortex panel is obtained in closed form. The vortex core of the side edge vortex is modeled by a concentrated core of …

An Investigation Of High Strength To Weight Corrugated Compression Panels With Non-Load Carrying Webs, Charles Thomas Lee Mills

Mechanical & Aerospace Engineering Theses & Dissertations

An investigation of the weight saving potential of corrugated compression panel concepts using curved elements and non-load carrying webs was performed. The concepts investigated were corrugated panels with flat and curved caps with beaded webs. These concepts utilize a beaded web that carries negligible axial load but is very stiff in the transverse direction. Therefore the web substantially stabilizes the load carrying caps to produce a high weight-strength efficient structure.

The optimum geometry parameters were determined using an iterative solution method employing simplified buckling assumptions. The results were checked with a non-linear optimization program coupled to a rigorous buckling analysis. …

Deterministic Linear Predictors For Bit Rate Improvement, Dhanvant H. Goradia

Electrical & Computer Engineering Theses & Dissertations

This thesis addresses the application of deterministic linear predictor s for telemetry based systems. Deterministic linear predictors are considered as a viable alternative to block transform coding in order to achieve bit rate reduction. A method of calculating the predictor coefficients of a deterministic linear predictor is presented. The system model is developed parametrically with respect to the bandwidth, polynomial order, signal class and predictor length. Two classes of signals, deterministic and random are analyzed and bounds on the performance of the deterministic linear predictor are established. A family of six pole Butterworth filters are used as presample filters in …

Laser Pump And Probe Excited State Absorption Measurements, Shawpin Jong

Electrical & Computer Engineering Theses & Dissertations

A pump and probe technique was used to investigate triplet-triplet excited state absorption in solutions of the scintillators 2,5 diphenyloxazole (PPO) and 2,1 naphthyl,5 phenylzole (a-NPO) in several solvents.

KrF excimer radiation (248 nm) was used to pump the samples under investigation as well as a tunable dye laser which was used as the probe. Time-resolution was obtained by changing the optical path difference between the pump and probe beams.

Transient excited state absorption was measured in a wide spectral region between 330 nm and 600 nm, showing a peak at 400 nm for PPO solutions, and two …

An Evaluation Of A Taylor-Galerkin Algorithm For High Speed Inviscid Flows Using Quadrilateral And Triangular Elements, Kim S. Bey

Mechanical & Aerospace Engineering Theses & Dissertations

The Taylor-Galerkin finite element algorithm is used to obtain solutions to the two-dimensional compressible Euler equations. The mathematical formulation of the algorithm is presented for a typical scalar equation. The derivation results in element equations which are assembled over the entire solution domain to obtain the system of equations that are solved explicitly. The algorithm has the unique feature that the finite element matrices can be evaluated in closed form, avoiding expensive numerical integration. Aspects of vector programming strategies and mesh generation important to an effective analysis procedure are also described. Solutions to supersonic flow problems with exact solutions are …

Convective Heat Transfer From Circular Cylinders Located Within Perforated Cylindrical Shrouds, Kamran Daryabeigi

Mechanical & Aerospace Engineering Theses & Dissertations

The influence of perforated cylindrical shrouds on the convective heat transfer to circular cylinders in transverse flow has been studied experimentally. Geometries studied were similar to those used in industrial platinum resistance thermometers. The influence of Reynolds number, ventilation factor (ratio of the open area to the total surface area of shroud), radius ratio (ratio of shroud's inside radius to bare cylinder's radius), and shroud orientation with respect to flow were studied.

The experiments showed that perforated shrouds with ventilation factors in the range 0.1 to 0.4 and radius ratios in the range 1.1 to 2.1 could enhance the convective …

Erosion Of Yellow Brass And Type 304 Stainless Steel In A Gas Blown Spark Gap, Rakasi Madhava Reddy

Mechanical & Aerospace Engineering Theses & Dissertations

Erosion rates of yellow brass and type 304 stainless steel electrodes were studied in air under pulse discharge conditions at a voltage of 100 kV, a current of 20 kA, and pulse durations of 70 ns. Anodes and cathodes, configured vertically, were fitted with removable hemispherical tips having a diameter of 0.95 cm and a mass of 3 gm. Tests were conducted inside a low speed, high pressure wind tunnel at pressures of 30 and 50 psig and air velocities ranging from 0 to 36 nm/s.

Erosion was studied gravimetrically for several flow velocities. As many as 60,000 discharges were …

Dynamic Analysis Of An Earth-Orbiting Satellite Deploying Hinged Appendages, Kevin Fielding Oakes

Mechanical & Aerospace Engineering Theses & Dissertations

The planar liberational dynamics of an arbitrary spacecraft with deployable hinged appendages is presented here both analytically and numerically. The system model consists of a central rigid satellite moving about the earth in a circular orbit at a uniform orbital rate. Attached to the satellite are two unfolding rigid booms with specified mass and length. Tip masses are included at the ends of each boom and deployment is driven by torsional springs at both frictionless hinge points. The equations of motion are developed for both a single- and double-appendage model through the use of Lagrange's equations. The formulation accounts for …

Computer Application Of Project Planning And Scheduling With Cpm, Mohamed Tarek Abdel-Aziz

Theses

Scheduling is one of the most important tools for project management and control, and the CPM is one of the techniques used in project scheduling.

The primary objective of this thesis is to develop a CPM computer package using a microcomputer. The package is constituted in Basic (Applesoft Basic) for use on Apple II Plus, IIe or IIc.

The package is intended to be available to users without sufficient knowledge about computer. And it consists of two computer programs. The first computer program is the CPM-I which schedules project activities with unlimited resources. The second computer program is the CPM-II …

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 …

Use Of Clay As A Landfill Liner, Mayur B. Desai

Theses

The purpose of this thesis is to study the factors affecting efficient functioning of clay material for containment of landfill materials. The study of liner-leacheate interaction is done from the consolidation and vane shear tests on various clays having different activities, and chemicals that are typically found in a municipal solid waste leachate and a leachate collected from an active landfill.

An effort was made to study the use of Atterberg limits to predict the suitability of a clay as a landfill liner for a given waste environment. The study indicates that there is a decrease in permeability of bentonite …

Analysis And Evaluation Of The Developments In The Use Of Coal, Farid Najib Elkheshen

Theses

This thesis is a survey and evaluation of the developments in the use of coal. It deals with the social, economic, physical, and biological impacts of such a shift. It examines the complete coal system, from extraction to combustion, including the key steps and policy initiatives. The United States, with 6% of the world's population, consumes about 33% of its commerical energy supply - while the available reserve coal is about 80% of total energy in the United States, with coal use representing only 17%, oil and gas about 78% at present.

Technologies under development that might reduce costs, increase …