Mechanical Engineering Commons^™

Superplastic Forming System Design, Keith Bain

Honors Capstone Projects and Theses

No abstract provided.

An Empirical Investigation Of Quality And Productivity Management Practices In Manufacturing Firms, Kiran Vuppalapati

Masters Theses

A growing number of firms are implementing the concept of Just In Time (JlT) manufacturing and Total Quality Management (TQM). This research examines the impact of these management philosophies in manufacturing firms.

This research identifies a set of critical organizational variables necessary for a successful . implementation and the organizational problems faced during their implementation. The major object is to test the performance of firms implementing both JlT and TQM against firms implementing none of these philosophies. Results show that JIT-TQM firms are more customer focused and have better employee relations than traditional firms. This study also compares the performance …

An Experimental Study Into The Role Of Routing Flexibility In The Justification Of Advanced Manufacturing Systems, Sanjay Pathak

Masters Theses

Increased competition in manufacturing has focused attention on advanced technologies. These costly technologies lead to difficulty in purchase justification using traditional methods. New methods quantify attributes relating to the flexibility of advanced systems. One such attribute is routing flexibility.

This thesis presents results of experiments into evaluation of routing flexibility. The performance of conventional dedicated machinery when compared with that of machines having routing flexibility indicates an advantage of flexible machinery. The thesis indicates a procedure for evaluation of different flexibilities and their comparison with conventional machinery in reality.

An empirical formula is developed that helps in quantifying routing flexibility …

Binaural Room Simulation, Brian A. Smith

Theses and Dissertations

Research in binaural and spatial hearing is of particular interest to the Air Force. Applications in cockpit communication, target recognition, and aircraft navigation are being explored. This thesis examines human auditory localization cues and develops a mathematical model for the transfer function of a sound signal traveling from an isotropic point source through a rectangular room to both ears of a listener. Using this model as a guide, non-head coupled binaural sound signals are generated in a binaural room simulation. Reflection and attenuation cues included in the computer generated signals are varied in order to determine which cues enhance the …

Primary Coolant Flow Characteristics As It Exits The Palisades Reactor, Gregory Alan Baustian

Masters Theses

During fuel cycles 9 and 10 at the Palisades Nuclear Power Plant, new phenomena have been observed using the resistance temperature devices installed in the reactor coolant piping. Oscillations in the temperature readings have been observed leading to the assumptions that there is temperature stratification of the coolant in the reactor hot-legs and that the coolant rotates as it leaves the reactor. In addition, oscillations in the bulk coolant flow within the two hot legs have been postulated. This report outlines work performed using computational fluid dynamics modelling which predict the observed and assumed flow characteristics of the Palisades reactor …

Deposition Of Particles In A Convergent Channel, Hsi-Chung Chiou

Dissertations

The deposition of suspensions for uniform flow in convergent channels under the combined influences of inertia, viscous, gravity and electrostatic image forces were studied theoretically. A two dimensional, steady, incompressible, laminar flow with uniform velocity profile was assumed.

It was found that when the ratio of charge parameter to gravity parameter, Q/G, is greater than 5, the deposition is dominated by the electrostatic image force alone and that the gravity effect can be neglected. When the ratio of charge parameter to gravity parameter, Q/G, is less than 0.001, the image force can then be neglected. It was also observed that …

Vibratory Size Segregation Of Particulate Matter, Anthony La Rosa

Theses

Size segregation imposed by vibration or shaking is an ubiquitous phenomenon whereby a large particle will rise to the top of a bed of smaller spheres upon vibration. Several mechanisms based on computer simulations have been proposed, however a complete theory remains elusive. The objective of this study was to perform experiments to study vibratory segregation of particles for varying size ratios and vibration parameters. More specifically, the rise time of a sphere from the bottom to the top of a vibrated bed was examined. It was found that the rise time decreased with an increase in amplitude for fixed …

Local Stress Factors Of Pipe-Nozzle Due To Radial Load, Circumferential And Longitudinal Moments, Junyu Lin

Theses

This thesis presents a series of stress factor data which provide more detailed information for the calculation of local stresses at the nozzle region, as well as the pipe region, of a pipe-nozzle intersection, subjected to an external radial load, circumferential bending moment, and longitudinal bending moment, respectively.

The pipe and nozzle thicknesses are assumed to be identical. Numerical solutions are obtained through the use of the finite element method. In obtaining the numerical solutions via ANSYS, the quadrilateral element is used to simulate the thin shell pipe-nozzle geometries. The local stresses, at eight different points on both the pipe …

Evaluation Of Collision Properties Of Spheres Using High-Speed Video Analysis, Jian Yu

Theses

Experimental evaluation of the collision properties of spheres is performed using video image analysis techniques. A high-speed Kodak EktaPro1000 video camera is utilized to record a collision sequence between two spheres at 1000 frames/sec, and then the images are analyzed to calculate three dimensional translation and rotation before and after the collision. These quantities are used to compute the collision properties for a pair of one inch nylon spheres, i.e. the coefficient of friction, and the coefficients of normal and tangential restitution. The focus of the thesis is on image analysis techniques that provide high accuracy results even though the …

Experimental Investigation Of Submerged, Turbulent, Axisymmetric Air Jet Impinging On A Flat Plate, Lan Xiao

Theses

Experimental investigation was carried out on the flow characteristics of a circular, submerged, turbulent, axisymmetric air jet impinging normally on a smooth, flat, square, Lucite plate and a sand paper covered plate. Jet issuing from a circular nozzle of 0.5 inch diameter while the Reynolds Number varying from 10,000 to 85,000 was investigated. The flow can be considered incompressible since the pressure and the velocity of the jet were not too high, with Mach Number of the order of 0.3.

Various flow parameters were measured to obtain the velocity and pressure distributions at the surface of the flat Lucite plate, …

Detection Of Planar Facets In Noisy Range Images, Ajey S. Atre

Theses

Segmentation of the image is one of the major tasks of a machine vision system designed for constructing a three-dimensional representation of the object being imaged. A robust approach for segmenting planar surfaces from range images is presented in this paper. An algorithm based on clustering through fuzzy covariance matrices, which has been proposed by Gustafson and Kessel is considered for planar segmentation. However this algorithm performs poorly if the data is noisy, which is usually the case in real life applications. In order to handle noisy data, a robust modification, based on the "noise clustering" concept, is introduced to …

Performance Of The Stirling Cycle Thermal Regenerator, Cesar A. Cravo

Theses

Most of the methods developed to analyze the performance of regenerators make assumptions which are not valid in Stirling cycle regenerators. To more adequately describe the conditions of an actual Stirling cycle regenerator a more complex method has been investigated. This method takes into account the time dependence of the mass flow and pressure fluctuations and considers the temperature dependence of the thermophysical properties.

The solution is accomplished by finite difference techniques. The solution determines the temperature distributions of the gas and matrix along the length of the regenerator and calculates the effectiveness over a cycle. A wide range of …

Processing And Application Of Polyolefin Plastics, Muhammad Khalid

Theses

This thesis describes the manufacturing, processing and application of polyolefin thermoplastics. Polyolefins have become one of the most important kinds of plastics. Polyolefin resin represents about one third of all plastics sold and its application for films and containers dominate the packaging industry. The objective of this thesis is to present the various processing methods and application of polyolefin thermoplastics. Polyolefin is produced by several different processes. Conventional low density polyethylene is made by polymerizing ethylene at high pressure and high temperatures while high density polyethylene is polymerized at relatively low pressure and low temperatures. Generally all polyolefin possess excellent …

An Application Of Neural Networks To Statistical Process Control, Asterios Papaikonomou

Theses

Recent changes in the past World War II economy have produced a more educated, value driven customer. A global economy has emerged to technological advances which has made competition fierce as well as proximate. As a result, manufacturing companies are required to provide consumers with quality products at a reasonable cost. A quality product is defined as one that fulfills the needs and expectations of the consumer and provides him with a sense of value.

Since all companies want to provide quality products, the reason why poor quality is sometimes the result is not the outcome of actions for that …

Statistical, Random And Fractal Characterizations Of Surface Topography With Engineering Applications, Gongyao Zhou

Dissertations

Two methods, namely the conventional and fractal geometry methods, are developed for surface topography characterization. The conventional method utilizing statistical and random process techniques is used to study waterjet machined surfaces. In the study the waterjet surfaces are separated into smooth and striation zones, where striation influence is negligible in the smooth zone. It is found that the smooth zone has a random, moderately isotropic texture, with the height distribution nearly Gaussian. In the striation zone the major frequencies of the surface profile power spectra are independent of cutting parameters, while the amplitudes of these frequencies monotonically increase with cutting …

Analysis Of Sandwich Plates Subjected To Blast Loading, Vijay Prasad Bulla

Masters Theses

A dynamic analysis is presented for the bending response of square sandwich plates with isotropic core and facings under blast type pressure. The maximum central deflections of simply supported plates under static and dynamic loadings are compared for various thicknesses and elastic moduli. The deviation of the thick sandwich plate results from the pure-bending theory results is presented for various core properties. Small deflection dynamic iso-response plots are shown for different core rigidities. To study the limits of small deformation linearity for various sandwich plates, non-linear results for deformations under high pressure loads are compared with the linear results. The …

Rolling Friction Research Instrument, John P. Ward

Masters Theses

An instrument has been analyzed, designed and constructed that will accurately measure the rolling resistance of metallic spheres an plane surfaces subjected to normal loading which will produce contact stresses approaching material yield.

Finite Element Analysis For An Involute Spur Gear Noise Excitation By Impact Effects, Wenbeen Li

Electronic Theses & Dissertations

The purpose of this study includes (1) to identify the relationship between the impact loads or backlash and the sound field pressure of impact direct noise of meshing gears, (2) to show that impact whether or not the impact direct noise contributes to the noise of overall gear system, and (3) to demonstrate how impact direct noise can be predicted. The method used to predict was finite element analysis and numerical solution. This research presents the analytical model of impact direct noise prediction for meshing gear teeth based on the data that the tooth vibration and surface are known by …

Single Scheduling Problem With Dependent Setup Cost, Mohamed Mahmoud Zaki

Archived Theses and Dissertations

No abstract provided.

Fiber Enhanced Viscoelastic Damping Polymers And Their Application To Passive Vibration Control, Houchun Xia

Mechanical & Aerospace Engineering Theses & Dissertations

A new composite damping material is investigated, which consists of a viscoelastic matrix and high elastic modulus fiber inclusions. This fiber enhanced viscoelastic damping polymer is intended to be applied to light-weight flexible structures as surface treatment for passive vibration control. A desirable packing geometry for the composite material is proposed, which is expected to produce maximum shear strain in the viscoelastic damping matrix. Subsequently, a micromechanical model is established in which the effect of fiber segment length and relative motion between neighboring fibers are taken into account. Based on this model, closed form expressions for the effective storage and …

Boundary Layer Influences On The Subsonic Near-Wake Of A Family Of Three-Dimensional Bluff Bodies, Charles Willliam Alcorn

Mechanical & Aerospace Engineering Theses & Dissertations

A study is reported on subsonic bluff body near-wake flows. It has been determined that one family of bluff bodies, namely slanted-base ogive cylinders, can experience either a closed recirculating near-wake, or a longitudinal vortex near-wake depending on the base slant-angle and the Reynolds number. This suggests a dependence of near-wake parameters on the state of the boundary layer ahead of separation. This report addresses the influence of the boundary layer on the near-wake of slanted-base bluff bodies. Experiments were conducted in two facilities, the 6-inch Magnetic Suspension and Balance System (MSBS) at NASA Langley Research Center and the Old …

Studies On Nonequilibrium Phenomena In Supersonic Chemically Reacting Flows, Rajnish Chandrasekhar

Mechanical & Aerospace Engineering Theses & Dissertations

This study deals with a systematic investigation of nonequilibrium processes in supersonic combustion. The two-dimensional, elliptic Navier-Stokes equations are used to investigate supersonic flows with nonequilibrium chemistry and thermodynamics, coupled with radiation, for hydrogen-air systems. The explicit, unsplit MacCormack finite-difference scheme is used to advance the governing equations in time, until convergence is achieved.

For a basic understanding of the flow physics, premixed flows undergoing finite rate chemical reactions are investigated. Results obtained for specific conditions indicate that the radiative interactions vary substantially, depending on reactions involving HO$\sb2$ and NO species, and that this can have a noticeable influence on …

Nonlinear Dynamic Finite Element Simulation Of Hydroelastic Mounts For Light Weight Vehicles, Talla Jayapal Reddy

Masters Theses

Modern light weight vehicles generate large noise levels, that may need bulky classical rubber mounts to suppress. Hydroelastic mounts can significantly reduce the vibration level of current production automobiles without weight penalty. However, the highly nonlinear behavior of hydroelastic mounts has not been established yet and its use is, therefore, limited to trial and error design methods.

This study discusses the implementation of nonlinear finite element simulation of hydroelastic mounts using the ANSYS finite element code. Fluid elements are limited to linear analysis and therefore are incompatible with the nonlinear hyperelastic elements. A method is proposed to simulate the fluid …

On Orthogonal Collocation Solutions Of Partial Differential Equations, Herli Surjanhata

Dissertations

In contrast to the h-version most frequently used, a p-version of the Orthogonal Collocation Method as applied to differential equations in two-dimensional domains is examined. For superior accuracy and convergence, the collocation points are chosen to be the zeros of a Legendre polynomial plus the two endpoints. Hence the method is called the Legendre Collocation Method. The approximate solution in an element is written as a Lagrange interpolation polynomial. This form of the approximate solution makes it possible to fully automate the method on a personal computer using conventional memory.

The Legendre Collocation Method provides a formula for …

Coordinate Measuring Machines : A Modern Inspection Tool In Manufacturing, Matthias Richard Mantel

Theses

Coordinate Measuring Machines (CMM) are flexible and universal dimensional measuring devices with the capability for full integration into a CIM information network. Developed as highly precise measuring machines for specially designed measuring rooms, today's CMMs are more and more used in shop floor applications which is a hostile environment for a precise measuring tool. CMMs are offered in a variety of configurations and levels of automation. For the CMM buyer it is therefore essential to have an overview of the different types of CMMs and their subsystems before making a purchasing decision.

To obtain reliable measuring results that are used …

Design And Development Of Flexible Manufacturing Cells - A Case Study, Behrouz Barzani

Theses

This paper covers the typical ills of American manufacturing companies and provides steps to selecting a flexible manufacturing cell(s) or system as a remedy. For that reason various definition of different types of flexibilities in manufacturing and the interrelationships between the several types have been examined. In addition, their purposes, means of obtaining them and some measurement and evaluations has been discussed. This was done to cover the basic but necessary requirements for understanding and selecting a flexible manufacturing system. Finally, the design process of a flexible system and its intuitive justification were discussed.

Simulation Of Manufacturing Cell Using Hoops Graphic Software And Siman Simulation Language, Parikh Vipul

Theses

Control of jobs being processed in manufacturing shop floor is important to management. The performance of job shop is affected by shop congestion due to arrival rate, batch size, number of machines, buffer capacity, process time variation, and dispatching rules use to load the jobs on the machine.

The job shop is a very complex system and hence, it is difficult as well as time consuming to obtained result using analytical method. A SIMAN simulation language is used to create generic model of a manufacturing cell and simulation analysis of those parameters variation such as job shop efficiency, the average …

Geometric Dimensioning And Tolerancing A Tool For Concurrent Engineering, Tapan Kumar S. K. Jain

Theses

The concept of Concurrent Engineering recognizes an immediate need for a new design environment and technology and so requires extensive interdisciplinary cooperation and integration of diverse functions of a manufacturing organization such as marketing, design, manufacturing and finance. One of the key factors to achieve successful integration among the departments is better communication and it becomes imperative in cases of varying levels of communication needs, especially in interdepartmental cases.

Concurrent Engineering is a philosophy which provides certain benefits. There are various tools and methods available for implementation of Concurrent Engineering concepts. One of the tools is Geometric Dimensioning & Tolerancing …

A Simulation Of A Monitoring And Alarm System In An Energy Management System, Hui-Jen Liu

Theses

This is a simulation for an energy system's monitoring and alarm and working under KEE's environment. Because of KEE's powerful capabilities, we can monitor and get warning signals from several active windows that we attaching them from KEE's system knowledge base to our source code.

It is very convenient for us to set every member of the energy system on an image panel. We can monitor the entire conditions of that member and get highlighted warning signals from its own image panel. Also we can initialize them by a kind of method-actuators windows if we want to restore the system.

A Mathematical Model For The Prediction Of Depth Of Cut In The Course Of Awj Machining, Naijian Ma

Theses

The objective of this study is to develop a practical mathematical model for prediction of the depth of cut in the course of Abrasive Water Jet (AWJ) machining. Semi-empirical method which is an integration of theoretical derivation and statistical analysis is used for process description. A theoretical model was constructed based on kinetic energy conservation equation, physical relationship among operating parameters, abrasive size, material properties and cutting results. Then, correlation between the depth of cut and operational parameters was analyzed in order to improve the theoretical model. Finally, a regression equation representing 1000 samples was constructed.

Three statistical criteria were …