Engineering Commons^™

Improved Techniques For Manufacturing Layered Laminate Composite Materials, Michael D. Grabber

Opportunities for Undergraduate Research Experience Program (OURE)

An increasingly important class of engineering materials are known as fiber reinforced composite materials. They offer outstanding mechanical properties, unique flexibility in design, and ease of fabrication. Because of this, fiber reinforced composites are being found more and more in such diverse applications as aircraft, space vehicles, automobiles, sporting goods, and appliances.

The main objective of this research project was to develop a procedure for which high quality composite plates could be manufactured. The procedure needed to be able to accommodate materials of various thicknesses as well as various sizes. We also wanted the procedure to be versatile enough to …

Long-Term Effects Of Neutron Absorber And Fuel Matrix Corrosion On Criticality, William Culbreth, P. Zielinski

Mechanical Engineering Faculty Research

Proposed waste package designs will require the addition of neutron absorbing material to prevent the possibility of a sustained chain reaction occurring in the fuel in the event of water intrusion. Due to the low corrosion rates of the fuel matrix and the Zircaloy cladding, there is a possibility that the neutron absorbing material will corrode and leak from the waste container long before the subsequent release of fuel matrix material. An analysis of the release of fuel matrix and neutron absorber material based on a probabilistic model was conducted and the results were used to prepare input to KENO-V, …

Minutes Ag Tractor Test And Power Committee April 28th, 1994, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Discussion and revision of Articles of Incorporation and Bylaws. Report of museum accession, inventory and steps to take

Design Of A Vibration Excitation Device, Brian Wallace, Brandon Dawe

Honors Theses

A vibration excitation source has been designed for use in beam and plate vibration laboratory demonstrations. This source is capable of providing single frequency excitations below 160 cycles per second (Hz). Since it will be used in a variety of experiments by students, ease of use and quick setup time have been major considerations of design. Performance of this source has been evaluated and will be presented along with one example application.

Motion Synthesis Of Mechanisms Using Constraint Manifolds In Image Space, Yeou-Kai Wu

Dissertations

Kinematic mappings, quaternion algebra, and constraint manifolds in the algebraic image space are applied to the problems of the dimensional synthesis of mechanisms. Dimensions of a mechanism are determined such that a tracer frame fixed on the coupler will pass through or at least as close as possible to the desired positions and orientations in the physical space as the input link rotates about its fixed joint. First, using kinematic mappings, the desired positions and orientations of the tracer frame of the mechanism can be mapped onto points in a hyperspace in which the motion of the tracer frame can …

Ole Miss Engineer 1994

Ole Miss Engineer

No abstract provided.

Internal Acoustic Excitation Of An Airfoil Surface For Drag Reduction, Wendy L. Holforty

Masters Theses

This research investigated the effects of internal acoustic excitation on the boundary layer and surface of an airfoil. A NACA 16- 018 symmetric airfoil was tested in the Western Michigan University wind tunnel. The shedding vortex frequency of the airfoil was determined using hot-film anemometry. Using stroboscopic and holographic interferometry, the natural frequencies of the airfoil surface were determined. The airfoil surface was tuned such that the frequency of the shedding vortex is a resonant frequency and two internally mounted acoustic drivers were used to excite the surface of the airfoil at the shedding vortex frequency. The effects on pressure …

Flow Simulations About Steady-Complex And Unsteady Moving Configurations Using Structured-Overlapped And Unstructured Grids, James Charles Newman Iii

Mechanical & Aerospace Engineering Theses & Dissertations

The limiting factor in simulating flows past realistic configurations of interest has been the discretization of the physical domain on which the governing equations of fluid flow may be solved. In an attempt to circumvent this problem, many Computational Fluid Dynamic (CFD) methodologies that are based on different grid generation and domain decomposition techniques have been developed. However, due to the costs involved and expertise required, very few comparative studies between these methods have been performed. In the present work, the two CFD methodologies which show the most promise for treating complex three-dimensional configurations as well as unsteady moving boundary …

Three-Dimensional Aerodynamic Shape Optimization Using Discrete Sensitivity Analysis, Gregory Wayne Burgreen

Mechanical & Aerospace Engineering Theses & Dissertations

An aerodynamic shape optimization procedure based on discrete sensitivity analysis is extended to treat three-dimensional geometries. The function of sensitivity analysis is to directly couple computational fluid dynamics (CFD) with numerical optimization techniques, which facilitates the construction of efficient direct-design methods. The development of a practical three-dimensional design procedures entails many challenges, such as: (1) the demand for significant efficiency improvements over current design methods; (2) a general and flexible three-dimensional surface representation; and (3) the efficient solution of very large systems of linear algebraic equations. It is demonstrated that each of these challenges is overcome by: (1) employing fully …

Optimal Active And Passive Control Design For A Slewing Piezoelectric Laminate Beam, Travis V. Dubois

Mechanical & Aerospace Engineering Theses & Dissertations

This thesis presents the development and experimental verification of a distributed parameter model for a slewing beam system with piezoelectric actuators and sensors. Also presented is the development of an optimal active control synergism which employs IMSC, (Independent Modal Space Control) and an optimally designed, viscoelastic damping treatment. The beam is pinned at the proximal end and patches of thin piezoelectric laminates are attached to its surface. Formulation is general enough to allow the patches to be located anywhere on the beam's surface. A viscoelastic material with a constraining layer covers the rest of the beam. The differential equation of …

Implementation Of A Multiblock Sensitivity Analysis Method In Numerical Aerodynamic Shape Optimization, James Matthew Lacasse

Mechanical & Aerospace Engineering Theses & Dissertations

A multiblock sensitivity analysis method is applied in a numerical aerodynamic shape optimization technique. The Sensitivity Analysis Domain Decomposition (SADD) scheme which is implemented in this study was developed to reduce the computer memory requirements resulting from the aerodynamic sensitivity analysis equations, Discrete sensitivity analysis offers the ability to compute quasi-analytical derivatives in a more efficient manner than traditional finite-difference methods, which tend to be computationally expensive and prone to inaccuracies.

The direct optimization procedure couples CFD analysis based on the two-dimensional thin-layer Navier-Stokes equations with a gradient-based numerical optimization technique. The linking mechanism is the sensitivity equation derived from …

Explicit And Iterative Lqg Controller Design, Min-Hung Hsiao

Mechanical & Aerospace Engineering Theses & Dissertations

This dissertation presents two new LQG controller designs, namely, explicit and iterative designs. For the explicit design, the explicit solutions to the corresponding Riccati equations of controller design for large structures with collocated rate sensors and actuators are derived. Numerically solving the Riccati equations for state feedback and state estimation is no longer required. Since the number of design parameters for either state feedback or state estimation equals the number of controlled modes, the performance of each mode can be easily adjusted. NASA's Spacecraft COntrol Laboratory Experiment (SCOLE) configuration is used to demonstrate the effectiveness of the explicit design.

For …

Unsteady Flow Simulations About Moving Boundary Configurations Using Dynamic Domain Decomposition Techniques, Guan-Wei Yen

Mechanical & Aerospace Engineering Theses & Dissertations

A computational method is developed to solve the coupled governing equations of an unsteady flowfield and those of rigid-body dynamics in six degrees-of-freedom (6-DOF). This method is capable of simulating the unsteady flowfields around multiple component configurations with at least one of the components in relative motion with respect to the others. Two of the important phenomena that such analyses can help us to understand are the unsteady aerodynamic interference and the boundary-induced component of such a flowfield. By hybridizing two dynamic domain decomposition techniques, the grid generation task is simplified, the computer memory requirement is reduced, and the governing …

Analysis Of Random Structure-Acoustic Interaction Problems Using Coupled Boundary Element And Finite Element Methods, Carl S. Pates Iii

Mechanical & Aerospace Engineering Theses & Dissertations

A coupled boundary element(BEM)-finite element(FEM) approach is presented to accurately model structure-acoustic interaction systems. The boundary element method is first applied to interior, two and three-dimensional acoustic domains with complex geometry configurations. Boundary element results are very accurate when compared with limited exact solutions.

Structure-interaction problems are then analyzed with the coupled FEM-BEM method, where the finite element method models the structure and the boundary element method models the interior acoustic domain. The coupled analysis is compared with exact and experimental results for a simplistic model. Composite panels are analyzed and compared with isotropic results. The coupled method is then …

Real Life Applications Of Photovoltaic Power To Hurricane Andrew Relief, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

On August 24, 1992, Hurricane Andrew struck the coast of South Florida and devastated Dade County leaving several hundred-thousand people homeless. Over a million residences were without electrical service, functional water and sewage systems and medical services for days and weeks in the aftermath of the storm. Emergency management teams, medical personnel, the military and countless public and private organizations staged a massive relief effort.

The staff at the Florida Solar Energy Center and SANDIA National Laboratory responded to the disaster with photovoltaics (solar electric) powered equipment to assist in the relief effort. Electricity generated by these systems were used …

Free Vibrations Of A Piezoelectric Body, J. S. Yang, R. C. Batra

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We present a systematic analysis of the eigenvalue problem associated with free vibrations of a finite piezoelectric body. The analysis is based on an abstract formulation of the three-dimensional theory of piezoelectricity. A series of fundamental properties of free vibrations of a piezoelectric body are proved concisely. The problem of free vibrations of a piezoelectric plate governed by the two-dimensional plate equations due to Mindlin is treated in a similar manner. © 1994 Kluwer Academic Publishers.

Apparatus And Method Of High-Pressure Waterjet Assisted Cooling/Lubrication In Machining, Radovan Kovacevic

Mechanical Engineering Faculty Patents

An apparatus for high-pressure waterjet assisted machining includes a drive motor, spindle and rotary cutting tool with cutting inserts. The apparatus further includes a high-pressure intensifier pump providing cutting fluid at a pressure greater than 50,000 psi. A cutting fluid conduit system in the rotary cutting tool includes a main flow channel, a distribution manifold, a plurality of radially extending feed channels and a plurality of cooperating nozzles for delivering fluid behind the cutting inserts. The cutting fluid then passes through one or more apertures in the inserts into an interface defined by the inserts of the cutting tool and …

Draft Of Articles Of Incorporation For Friends Of The Tractor Test Museum, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

No abstract provided.

Museum Committee Meeting February 1994, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Master's student Tour of Museum

Minutes Friends Of Tractor Test Museum Feb. 1994, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Articles of Incorporation Museum Inventory Roof Protection

Inhomogeneous Anisotropic Percolation: Two-Dimensional Numerical Threshold Analysis, Yuris A. Dzenis, S. P. Joshi

Department of Engineering Mechanics: Faculty Publications

Monte Carlo simulations of percolation on a square lattice with anisotropic inhomogeneous probability distribution are reported. Finite-size scaling is used for data analysis. As inhomogeneity increases, the critical probability decreases; whereas the correlation-length exponent remains, within computation errors, the same as in classical two-dimensional percolation.

Numerical Investigation Of Flow Through Wide Angle Diffusers, Moududur Rahman

Dissertations

This study is aimed at the development of a computational technique for the prediction of the flow field in wide angle diffusers. The finite element technique is used for the solution of the governing equations. A commercial software package, NISA/3DFlUID, modified for this specific application was used. The parameters affecting the flow field have been identified. For a wide range of variation of these parameters, the effects on the flow field have been examined. This investigation is an exhaustive and comprehensive numerical study of diffuser flows. Such a study will result in substantial improvement in the understanding of the anatomy …

An Investigation Of The Formation Of Turbulent Water And Abrasive Water Jets, Md. Ekramul Hasan Khan

Dissertations

This study is concerned with the development of a knowledge base for the selection of nozzle geometry by investigating the mechanism of formation and behaviors of water and abrasive water jets. A numerical prediction of turbulent water flow inside various nozzles is developed. The analysis is based on the numerical solution of conservation equations of continuity and momentum as well as equations of turbulent kinetic energy and dissipation for 2-dimensional axisymmetric flow by using a finite element package, FIDAP.

The technique for determining velocities and forces of water jet and abrasive water jet with the Laser Transit Anemometer and Piezoelectric …

Computer Aided Stress Analysis Of The Femur With Prosthetic Hip Stem Utilizing Computed Tomography, Wei-Chun Chang

Dissertations

A computer aided design and analysis method, utilizing computed tomography (CT) is developed, which together with a finite element program determines the stress and deformation patterns in the femur with hip prosthesis. The CT scan data file provides the geometry and the material parameters for the generated finite element model. The three-dimensional finite element model of the femur with hip prosthesis is automatically generated from the CT data file by a preprocessing procedure. The preprocessor includes a CT image display, edge detector, nodes generation, prosthesis simulator, mesh generator and model display. The loading conditions applied on the finite element model …

Design Of An Autonomous Vehicle System, Fritz Gerald Momplaisir

Theses

With advances in electronics, mobile vehicles are becoming more and more sophisticated. The Potential applications of AGVs are numerous an range from a material handling system for the factory floor to an intelligent wheel chair for the handicapped. The design of these vehicles, however, remains a difficult task. Even when the machine is given precise information about its environment, the fact that it is never free of noise further complicate the situation. One of the goals of an AGV project is to design a robust system that will operate efficiently in the presence of different sources of noise.

The scientific …

Base Plate Placement For A Predefined Workspace Of A Stewart Platform Parallel Manipulator, Rajesh Chanda

Theses

This thesis deals with solving the problem of placing the base plate in an optimum position and orientation in a three dimensional space for the desired locations of the mobile end platform of a Stewart platform parallel manipulator.

First the workspace of the mobile plate is expressed as a function of the base plate position. Then the objective function is generated by summing the squared distances from the various desired locations of the mobile plate to the center of the platform's workspace. This function consists of six unknown variables which define the position and orientation of the base plate. A …

Machining Of Silicon Wafers With An Abrasive Water Jet Cutter, Frank J. Marciniak

Theses

This thesis consists of a study of the effects of abrasive water jet cutting on brittle silicon substrates. In total, 26 different cuts were made in a single crystal silicon substrate with an abrasive water jet cutter under different conditions of water flow, water pressure, and abrasive flow rate. These cuts were analyzed for surface roughness, and microstructure.

The roughness measurements were compared in order to determine the best possible cutting conditions. The cut with the best roughness of 0.000170 inches was obtained under cutting conditions of 30 KSI water pressure, 1 inch/minute cutting speed, and an abrasive flow rate …

Concurrent Engineering And Design For Manufacture In The Medical Device Industry, Martin A. Mathelier

Theses

Concurrent Engineering (CE) is an approach to product development in which engineers work on design and manufacturability at the same time. The ultimate goal of concurrent engineering is to reduce the time-to-market while improving quality. This thesis goes into details about the tools necessary to achieve successful product development in the Medical Device Industry. The novelty of this thesis is not in the tools themselves but rather in the way that they are applied to the medical device industry. The need for the CE approach is of utmost importance because of the vast competition in the medical device industry.

The …

Prediction Of Linear And Non-Linear Components Of Cutter Deflection In End Milling Tools, Kimberly Nazimek

Theses

In this study, cutter length, cutter diameter, depth of cut, and magnitude of the instantaneous force vector are examined to determine their effects on cutter deflection during end milling. Their contributions to both linear and non-linear cutter deflection are examined. Models are developed to compute deflection for both flat and ball end mills. These models are evaluated to determine the contribution of each type of deflection encountered during a variety of milling conditions. A discussion on the transfer of deflection data to an estimation of machining accuracy is then presented.

A Knowledge-Based Designer Assistant System With Application To The Design Of Helical Springs, Giridhar Raja

Theses

Design problems are generally difficult to solve because the domain of solutions is often infinite (like design of gears, bearings, shafts, springs etc.) and generally requires several iterations before we can arrive at the right solution. The search for the right solution satisfied by several constraints is also time consuming. Thus design intrinsically requires backtracking and several iterations to obtain the desired solution.

In the design of helical springs where the load, deflection, allowable stress, and material are specified, there are an infinite number of solutions. If, in addition to these requirements, the mean coil radius, wire diameter, free height …