Engineering Commons^™

Teaching Mechanical Design Using The Axiomatic Approach, Lisa E. Hailey

Theses

Many authors on the subject of design state that it cannot be taught, it must be learned through experience. This thesis offers a method in which design can be taught to senior mechanical engineering students. The axiomatic approach to design, authored by Dr. Nam P. Suh of the Massachusetts Institute of Technology, states that all good designs follow two axioms, the independence axiom and the information axiom. By teaching students to use these axioms, and the corollaries and theorems derived from the axioms, educators can teach students the basic concepts of good design.

To show how this approach can be …

Investigation Of Material Erosion By Abrasive Water Jet Cutting, Fang Hu

Theses

This study is concerned with the investigation of material erosion phenomena occurring in the abrasive waterjet (AWJ) cutting process.

A series of scratches were generated by the abrasive waterjet on the polished surface of aluminum samples. The tests were carried out at different traverse speeds, abrasive flow rates, diameters of sapphire nozzles, diameters of carbide tubes and initial abrasive particle sizes. Material volume loss in the erosion zone was measured directly or calculated by the use of the suggested mathematical models. An analysis of experimental results enabled us to introduce a new process criterion, particle distribution density, which determines the …

Simulation Of Random Packing Of Hard Spheres Using Monte Carlo Method, Sung-Ho Park

Theses

A computer based method of generating a random packing of hard spheres is described. Using a Monte Carlo method as employed in the field of Computational Statistical Physics, packing of hard spheres are generated and analyzed.

The mean packing fractions for the present assemblies of 1000 spheres are 0.555±0.015 after pouring and 0.582±0.018 after 10 cycles of shaking. These values are approximately 5 to 6 per cent lower than the experimental results of G.D. Scott[30], but similar with the result of Visscher & Bolsterli [17].

The mean coordination numbers are 5.97 and 6.33 for the pouring and shaking case, respectively. …

An Effective Cube Comparison Method For Discrete Spectral Transformations Of Logic Functions, Ingo SchäFer

Dissertations and Theses

Spectral methods have been used for many applications in digital logic design, digital signal processing and telecommunications. In digital logic design they are implemented for testing of logical networks, multiplexer-based logic synthesis, signal processing, image processing and pattern analysis. New developments of more efficient algorithms for spectral transformations (Rademacher-Walsh, Generalized Reed-Muller, Adding, Arithmetic, multiple-valued Walsh and multiple-valued Generalized Reed- Muller) their implementation and applications will be described.

Expert System For The Material Selection Of Steam Piping, Ayman Mohamedein

Archived Theses and Dissertations

No abstract provided.

Trends In Air Transportation Between The Usa And The Asia/Pacific Region With Particular Consideration Of United Airlines' Acquisition Of The Pan Am Pacific Division, Michael Hanke

Master's Theses - Daytona Beach

This study deals with the development of scheduled passenger traffic between the USA and selected countries in the ICAO Asia/Pacific region from 1977 to 1987. Among the significant trends are the growth in scheduled passenger traffic volume and the increase in both the percentage share of US citizens and foreign flag carriers. This study focuses on United Airlines' acquisition of Pan Am's Pacific Division in 1985. An analysis of selected Pan Am transpacific services in terms of market share and quality of service before 1985 shows a general declining trend. The main reasons for this development include Pan Am's poor …

Thermohydrodynamic Analysis Of A Boiling Water Reactor, Nahed Youssef Morcos

Archived Theses and Dissertations

No abstract provided.

An Expert System For Underground Water Piping Material Selection, Amal Esawi

Archived Theses and Dissertations

No abstract provided.

Knowledge Based Expert System For Flexible Pavement Design In Egypt, Magdy Youssef Mikhail

Archived Theses and Dissertations

No abstract provided.

An Expert System For Underground Under Gravity Sewer Piping Material Selection, Nader Wahib Morcos

Archived Theses and Dissertations

No abstract provided.

An Expert System For Failure Analysis Of Rotating Steel Shaft, Dalal Eissa Ahmed

Archived Theses and Dissertations

No abstract provided.

Computer Data Acquisition, Control, And Analysis For The University Of Tennessee At Chattanooga's Internal Combustion Engine Labratory, Ahmad Noureddine

Masters Theses and Doctoral Dissertations

For any data acquisition instrumentation, it is essential to have a voltage or current signal output from any transducer that needs to be monitored.Nine OMEGA thermocouples were installed on the Ford engine-Megatech dynamometer system to monitor the temperature of the exhaust gases at different locations and the coolants entering and leaving the dynamometer and the radiator.Those thermocouples have an output signal of O - 55 mv.The TESCOM gas analyzer system measures the concentrations of the different gases present in the exhaust system of the engine and produces an analog output signal (0 - 100 mv) that is used for data …

The Frontal Method For Finite Element Analysis On Ibm-3090 Vector Computer, Chaerul Kamal

Civil & Environmental Engineering Theses & Dissertations

In this report, a Finite Element program based on the Frontal method was implemented on the IBM-3090 to exploit the vector capabilities offered by modern high performance vector computers. The overall computational speed for the Frontal Finite Element program was increased by 30% when the vector instructions were introduced. The Frontal solution for a system of simultaneous linear equations, however, has shown only minor improvement when vector instructions were used. More improvement in computational speed and memory storage can be expected by using the Parallel Frontal method with Substructures.

The Impact Of Birthdate Biorhythms On Aviation Accidents Involving Hellenic Air Force Fighter Pilots, Ioannis Fokas

Master's Theses - Daytona Beach

This study investigated the impact of birthdate biorhythm on aviation accidents involving Hellenic Air Force fighter pilots. A list of names, birthdates, and the dates of accidents was compiled from accidents involving pilots who had flown fighter aircraft and have reacted improperly even though they had sufficient time to implement the proper procedures. The list was acquired from the History Office of the Hellenic Air Force. A computer program was acquired for the specific purpose of tracking the pilot's birthdate biorhythm cycles. The Standardized Statistic Test for Proportion was used for statistical inferences. The results suggest that the date of …

Finite Element Evaluation Of The Elastic-Plastic Fracture Parameters, Ibrahim Medhat Ibrahim Ayoub

Archived Theses and Dissertations

No abstract provided.

An Experimental Study Of An Axisymmetric Turbulent Boundary Layer Disturbed By A Periodic Freestream, Chithrabhanu Koodalattupuram

Mechanical & Aerospace Engineering Theses & Dissertations

Behavior of an axisymmetric equilibrium turbulent boundary layer disturbed by a propeller wake in the freestream was investigated experimentally. Tests were conducted in a low speed wind tunnel and measurements of turbulence quantities were made using an X wire probe and a constant temperature anemometer. The boundary layer flow on a cylindrical body was characterized by measuring its gross parameters and comparing them with classical values. Propeller speed was measured using an electronic circuit whose output signal was also used to trigger hot wire probe. Gross boundary later characteristics of the disturbed boundary layer did not deviate appreciably from the …

Experimental Studies Of Bulk Optically Controlled Gaas Switches Utilizing Fast Infrared Quenching, Michael S. Mazzola

Electrical & Computer Engineering Theses & Dissertations

This dissertation describes some of the properties of copper-compensated, silicon-doped GaAs (Cu:Si:GaAs) with the purpose of demonstrating the feasibility of the Bulk Optically Controlled Switch (BOSS) concept. The BOSS concept involves the excitation of electrons or holes from selected deep centers in the band gap of a bulk Cu:Si:GaAs photoconductor. The conductivity of the Cu:Si:GaAs crystal can be increased or decreased on command by irradiating the crystal with laser light of different wavelengths in the infrared. Photoconductivities as large as 1 (Ω cm^)-1 were measured to persist for microseconds after illumination by a 7 ns laser pulse with wavelength …

Control And Mechanism Interaction For Ground-Based Testing Of Space Structures, Li-Farn Yang

Mechanical & Aerospace Engineering Theses & Dissertations

In the ground-based validation testing, the adverse effect of terrestrial conditions such as a gravitational force interferes with the dynamic behavior of space structures. A suspension system is developed to assess the structural characteristics in a simulated zero-gravity environment. Using a mechanisms approach, the synthesis of a noncircular disk with a torsional spring at its rotational axis is designed to counteract the gravitational force of test structures during the testing.

The multibody dynamics of a flexible steel beam carried on a rigid trolley has been investigated. The system is constructed in such a way that the rapid and large-angle slewing …

Analysis And Development Of A Switched Capacitor Power Supply, John Richard Hackworth

Electrical & Computer Engineering Theses & Dissertations

The combination of a switched capacitor network and switching power supply techniques can result in a transformer less regulated DC power supply that is small, relatively simple, and efficient. In addition, the output of such a system could be operated over a wide range of common mode voltages. Multiple switched capacitor supplies could be stacked to achieve voltage multiplication.

Although the output of a system of this type is a continuous function, the internal operation must be analyzed in finite time elements. This numerical analysis will be shown in both a mathematical approach and a computer model.

Diagnostics Software For Concurrent Processing Computer Systems, Robert L. Jones Iii

Electrical & Computer Engineering Theses & Dissertations

Diagnostics software for analyzing ATAMM based concurrent processing systems is presented in this thesis. ATAMM (Algorithm to Architecture Mapping Model) is a new model developed by researchers at Old Dominion University and the NASA-Langley Research Center. ATAMM is capable of modeling the execution of large grain algorithms on distributed data flow architectures. Investigating a real or simulated ATAMM based system requires the aid of software tools. The software tool presented in this thesis can evaluate the behavior and performance of an ATAMM based system. The tool graphically portrays algorithm activities and processor activities. The tool's measurement capabilities indicate computing speed, …

Hydrogenation Effects On Trap Related Conduction In Diamond, Linwood Cleveland Watkins Iii

Electrical & Computer Engineering Theses & Dissertations

In this research work, the results of an experimental investigation on the electrical conduction mechanism in type Ιa and Ilb diamonds are presented. These results are compared with those of previous theoretical studies. The basic physical properties of diamond are discussed. Details of ohmic contact formation on diamond are presented.

The current-voltage characteristics revealed the presence of traps located below the Fermi level. The unfilled trap density was determined. The deep traps were further studied using spectroscopic photoconductivity measurements and the trap energy levels were determined.

The effects of hydrogenation on trap related conduction were studied subsequently. Hydrogenation was carried …

A Systematic Procedure For The Analysis And Design Of Deployable Space Structures, Praveen Kumar

Mechanical & Aerospace Engineering Theses & Dissertations

An integrated graph theory and a symmetry-based approach have been developed for the type synthesis of deployable truss structures. Using this systematic approach, a bay of a deployable structure may be looked upon as being built around an axis or a plane of symmetry, including anti-symmetry. By providing a fictitious joint along this axis, the problem of structural design and analysis can be reduced to the study of one plane or face of the given structure. Each face is considered to be an assemblage of structural links connected by joints which form a closed kinematic chain. The conventional graph representation …

A Detailed Analysis Of Dynamic Robotic Simulation, Lonnie J. Love

Mechanical & Aerospace Engineering Theses & Dissertations

Future space missions may require the utilization of automation technology for assembly, maintenance, repair, and a variety of repetitive or hazardous operations. Many tasks which are likely candidates for robotic or telerobotic execution are either difficult or impossible to duplicate in the laboratory. With an accurate simulation package, many of these tasks can be evaluated by computer simulation before committing the resources required for laboratory experimentation. With this motivation, the ROBSIM robot simulation software has been developed by NASA Langley Research Center in conjunction with the Martin Marietta Corporation. ROBSIM is a versatile tool with features including the ability to …

Nonproportionally Loaded Steel Beam-Columns And Flexibly-Connected Nonsway Frames, Siva Prasad Darbhamulla

Civil & Environmental Engineering Theses & Dissertations

A theoretical study of the inelastic stability of nonproportionally loaded steel beam-columns and flexibly-connected frames is conducted. Specifically, solution techniques are formulated to predict the nonlinear behavior of cross sections, spatial beam-columns, and nonsway plane frames under the combined influence of imperfections, flexible connections, and nonproportional loads. A set of new inelastic slope-deflection equations for imperfect members are derived and their use illustrated through in-depth studies of flexibly-connected portal and two-bay two-story frames. These equations are derived from a system of nonlinear ordinary differential equations. The member studies are carried out using a second-order finite-difference solution to a set of …

A Case Study In The Development Of A Cost Reduction Methodology In The Public Sector, Ross Cooper Haines

Engineering Management & Systems Engineering Theses & Dissertations

Intense fiscal pressures have caused the Department of Defense (DoD) to explore new ways of reducing operating expenses. The primary technique used to achieve this objective is the use of competition - recently for maintenance requirements not previously subjected to competition. One such maintenance requirement is the periodic overhaul of one of the Navy's front line fighter aircraft - the F-14A Tomcat. This case study documents the cost reduction methodology developed by the DoD's incumbent overhaul facility in preparation for competition. The methodology discusses task time estimation, cost center structure, labor rate development and analysis, internal cost transfers as well …

Eigensensitivity Analysis For Space Structures With Applications In Design Optimization, Sean Patrick Kenny

Mechanical & Aerospace Engineering Theses & Dissertations

Eigensensitivity analysis is concerned with the rates of changes of eigenvalues and eigenvectors with respect to design variables. Eigensolutions of space structures are found to display four distinct characteristics, three of which are related to various types of repeated eigenvalues. This study will address three cases of the real symmetric structural eigenvalue problem. The three cases that will be considered are: distinct eigenvalues, repeated eigenvalues with distinct first eigenvalue derivatives, and repeated eigenvalues with infinitely repeating eigenvalue derivatives. Analytic formulations for eigenvalue/ vector derivatives will be presented for each of the three cases. The directional differentiability of eigenvalues for the …

The Influence Of Payload Dynamics On Trajectory Tracking Performance Of Robot Manipulator, Atul G. Kelkar

Mechanical & Aerospace Engineering Theses & Dissertations

Future space mission plans call for extensive use of remote manipulator systems for tasks such as assembly of lunar vehicles or space station modules, servicing of satellites, etc. These tasks demand very high precision end-effector motion control. Methods for compensating manipulator dynamics to achieve better trajectory tracking performance have been investigated by many researchers. Still, it is not always clear whether the added complexity of dynamic compensation is warranted for a given system. As an aid in evaluating when dynamic compensation is required, this thesis presents a method for the determination of maximum endpoint tracking error due to uncompensated inertial …

Radiative Interactions In Laminar Duct Flows, Prakash A. Trivedi

Mechanical & Aerospace Engineering Theses & Dissertations

Analyses and numerical procedures are presented for infrared radiative energy transfer in gases when other modes of energy transfer occur simultaneously. Two types of geometries are considered, a Parallel Plate Duct and a Circular Duct. Fully developed laminar incompressible flows of absorbing-emitting species in black surfaced ducts are considered under the conditions of uniform wall heat flux. The participating species considered are OH, CO, CO₂, and H₂O. Nongray as well as gray formulations are developed for both geometries. Appropriate limiting solutions of the governing equations are obtained and conduction-radiation interaction parameters are evaluated. Tien and Lowder's …

Hypercard-Based Learning Environment For Diades, Ali A. Shamsapour

Dissertations and Theses

This thesis is an attempt to create a HyperCard-based learning environment to teach DIADES and other related material. It is a departure from the classical Computer Aided Instruction methods towards a more flexible and user-controlled design. The goal was to set the foundation of a new CAI design which would closely resemble a Hyper-Text system. These systems are characterized as having interconnections between related concepts in the CAI environment.

Investigation Of Techniques For High Speed Cmos Arbitrary Waveform Generation, Albert Henry Nehl

Dissertations and Theses

Today a growing number of applications in design engineering, production and environmental testing, and system service require specific analog waveforms and digital patterns. Such requirements are neither satisfactorily nor easily met by the use of standard function or single purpose, custom generators.

Traditional methods of waveform generation suffer from undesirable complexity or mediocre performance and are otherwise limited. For the majority of arbitrary waveform generation applications, including medical engineering, modal analysis and electronic engineering, direct digital synthesis techniques are satisfactory. Direct digital synthesis, based generally on periodic retrieval of predetermined amplitude values, may be used to generate such waveforms. Within …