Engineering Commons^™

Development Of Vibration And Sensitivity Analysis Capability Using The Theory Of Structural Variations, Ting-Yu Rong

Mechanical & Aerospace Engineering Theses & Dissertations

In the author's previous work entitled "General Theorems of Topological Variations of Elastic Structures and the Method of Topological Variation," 1985, some interesting properties of skeletal structures have been discovered. These properties have been described as five theorems and synthesized as a theory, called the theory of structural variations (TSV). Based upon this theory, an innovative analysis tool, called the structural variation method (SVM), has been derived for static analysis of skeletal structures (one-dimensional finite element systems).

The objective of this dissertation research is to extend TSV and SVM from one-dimensional finite element systems to multi-dimensional ones and from statics …

Investigation Of Wall Injectors For Supersonic Mixing Enhancement, Yaacov Haimovitch

Mechanical & Aerospace Engineering Theses & Dissertations

A comparative study of the interaction between wall mounted swept-ramp injectors and injector nozzle shape has been conducted in a constant area duct to explore techniques to enhance mixing in scramjet combustors. The scramjet combustors are currently being developed for propulsion systems applications on the envisioned hypersonic vehicles. Short combustor residence time, a requirement for fuel injection parallel to the main flow in the combustor, and an overall strong sensitivity of the vehicle performance to the propulsion system motivated the investigation. The swept-ramp injector investigated in this study produces vortex shedding and local separation downstream of the injector's nozzle exit, …

Radiative Interactions In Multi-Dimensional Chemically Reacting Flows Using Monte Carlo Simulations, Jiwen Liu

Mechanical & Aerospace Engineering Theses & Dissertations

The Monte Carlo method (MCM) is applied to analyze radiative heat transfer in nongray gases. The nongray model employed is based on the statistical narrow band model with an exponential-tailed inverse intensity distribution. The amount and transfer of the emitted radiative energy in a finite volume element within a medium are considered in an exact manner. The spectral correlation between transmittances of two different segments of the same path in a medium makes the statistical relationship different from the conventional relationship, which only provides the noncorrelated results for nongray analysis. Two features of the MCM that are different from other …

Numerical Solution Of Nonequilibrium Compressible Nozzle Turbulent Boundary Layers Using Laws Of The Wall And Wake, Ajit A. Prabhu

Mechanical & Aerospace Engineering Theses & Dissertations

Accurate prediction of the development of the boundary-layer thickness is essential in designing hypersonic wind tunnel nozzles using computational fluid dynamics (CFD). The nozzle boundary-layer thickness becomes extremely thin at the throat region. Immediately downstream of the throat, as the flow begins to expand, the boundary-layer thickness grows rapidly. Estimates of grid requirements for resolving the turbulent boundary layer in the throat region using a Navier-Stokes solver have shown that the number of grid points is typically an order of magnitude greater than what is needed to resolve the nozzle exit region. Approximately 80% of the total time taken to …

Use Of The Genetic Algorithm In Positioning Sacrificial Anodes For Optimum Cathodic Protection, Chi-Cheng Tsao

Mechanical & Aerospace Engineering Theses & Dissertations

A systematic design methodology is developed in this thesis to automatically determine the best locations to place the anodes in order to obtain the maximum cathodic protection. The design methodology numerically solves a design optimization problem which selects the locations to place the anodes to maximize the difference between the minimum current density supplied by sacrificial anodes on the surface of the cathodic materials and its free corrosion current density. The numerical tools used in this design methodology are the finite element analysis and the genetic algorithm. The former analyzes the current density distribution in the field of concern and …

Inversion Of Light Scattering Measurements For Particle Size And Optical Constants: Theoretical Study, Matthew R. Jones, Bill P. Curry, M. Quinn Brewster, Keng H. Leong

Faculty Publications

We invert the Fredholm equation representing the light scattered by a single spherical particle or a distribution of spherical particles to obtain the particle size distribution function and refractive index. We obtain the solution by expanding the distribution function as a linear combination of a set of orthonormal basis functions. The set of orthonormal basis functions is composed of Schmidt-Hilbert eigenfunctions and a set of supplemental basis functions, which have been orthogonalized with respect to the Schmidt-Hilbert eigenfunctions by using the Gram-Schmidt orthogonalization procedure. We use the orthogonality properties of the basis functions and of the eigenvectors of the kernel …

Inversion Of Light Scattering Measurements For Particle Size And Optical Constants: Experimental Study, Matthew R. Jones, Keng H. Leong, M. Quinn Brewster, Bill P. Curry

Faculty Publications

Measurements of the light scattered by a sample contain information regarding the physical properties of the sample. Laser light-scattering measurements can be made unobtrusively in environments that are inaccessible to other types of measurements, so laser light-scattering techniques have become an important tool in aerosol research. The primary difficulty associated with using light-scattering techniques to determine aerosol particle properties is inverting the measurements or extracting the desired information from the measurements. In this study we use a 15-channel polar nephelometer to measure the light-scattering patterns of monodisperse polystyrene spheres. The light-scattering measurements are inverted, and the particle size distribution function …

Impression Creep Behavior In Weldments, S.H. Wang

Journal of Marine Science and Technology–Taiwan

At high temperature application, the failures of dissimilar metal weldments associated with the relevant degradation processes, which include chemical diffusion, oxide notching, precipitation, softening of the heat affected zone (HAZ), and creep type voids leading to cracking. This reveals that a creep in a gradient related to the microstructural degradation exists. The impression creep test was applied to monitor the effects of microstructural gradients on the localized high temperature creep properties in an autogeneous GTA aluminum weldment, and an austenitic stainless steel to ferritic steel dissimilar metal weldment respectively. To simplify the complexity of microstructural gradients, multipass weldments in A36 …

Vibration Analysis Of Timoshenko Beams Traversed By Moving Loads, Yih-Hwang Lin

Journal of Marine Science and Technology–Taiwan

The purpose of this research is to apply the finite element method for dynamic analysis of Timoshenko beams traversed by moving loads. When an elastic structure is subjected to moving loads, the induced displacements and stresses are much higher than those of static loading conditions. Due to the prevalence of high speed machinery and the use of light and flexible structures to reduce the material cost, structural weight, and space requirement, dynamic analysis of such systems becomes crucial to ensure structural safety and required accuracy. In this study, the shear effect and rotary inertia were included for the analysis of …

Analysis Of Homogeneous Slurry Pipe Flow, R. C. Chen

Journal of Marine Science and Technology–Taiwan

An analysis is performed for the solid-liquid slurry pipe flow in the homogeneous flow regime. The transport and concentration equations are constructed based on two-liquid postulation and modified Rouse-Schmidt diffusion relation. By considering the interphase interaction effects, a general k-e model is applied to describe the turbulent kinetic energy production and dissipation. Coupling with the physically-defined parameters, this model is able to obtain the axial velocities of the solid and liquid phases, the solid concentration distribution and the liquid turbulent kinetic energy and dissipation rate. Excellent agreement between the calculated axial velocity profiles and the experimental data obtained by Chen …

Viscoelastic Buckling And Postbuckling Of Circular Cylindrical Laminated Shells In Hygrothermal Environment, N.N. Huang

Journal of Marine Science and Technology–Taiwan

The viscoelastic buckling and postbuckling behaviors of fiber-reinforced plastic (FRP) circular cylindrical shells, operating in the hygrothermal environment, subjected to uniform external pressure are investigated in this study. The FRP is assumed to be a hy grothermorheologically simple material (HTSM). The analysis is conducted within the framework of the quasielastic approach. The finite element method is employed to examine both buckling and postbuckling behaviors for shells having arbitrary layups. The arc-length algorithm is incorporated into the finite element formulations to trace the postlimit equilibrium path. The structural responses of Glass/Epoxy shells are reported.

A Preliminary Model For Lot Sizing In Semiconductor Manufacturing, Tali F. Carmon, Steven Nahmias

Industrial and Manufacturing Engineering

No abstract provided.

A Recursive Least Squares Training Algorithm For Multilayer Recurrent Neural Networks, Q. Xu, K. Krishnamurthy, Bruce M. Mcmillin, Wen Feng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Recurrent neural networks have the potential to perform significantly better than the commonly used feedforward neural networks due to their dynamical nature. However, they have received less attention because training algorithms/architectures have not been well developed. In this study, a recursive least squares algorithm to train recurrent neural networks with an arbitrary number of hidden layers is developed. The training algorithm is developed as an extension of the standard recursive estimation problem. Simulated results obtained for identification of the dynamics of a nonlinear dynamical system show promising results.

Identification Of Cutting Force In End Milling Operations Using Recurrent Neural Networks, Q. Xu, K. Krishnamurthy, Bruce M. Mcmillin, Wen Feng Lu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The problem of identifying the cutting force in end milling operations is considered in this study. Recurrent neural networks are used here and are trained using a recursive least squares training algorithm. Training results for data obtained from a SAJO 3-axis vertical milling machine for steady slot cuts are presented. The results show that a recurrent neural network can learn the functional relationship between the feed rate and steady-state average resultant cutting force very well. Furthermore, results for the Mackey-Glass time series prediction problem are presented to illustrate the faster learning capability of the neural network scheme presented here

Running With The Pack: Jit & Automation For Small Manufacturers, Thomas E. Phillips, John R. Ledgerwood

Publications

While both just in time (JIT) concepts and automation programs have been widely implemented and highly successful in large manufacturing companies, many smaller manufacturing companies have wondered whether it would be economically feasible to utilize these same techniques and derive these same benefits. When JIT is adopted by small manufacturers, it provides them with advantages over traditional manufacturing systems, such as lower cost, quality improvements, higher productivity, and less working capital tied up in inventory. Small US manufacturers must understand the basic principles and philosophy of JIT and update their production equipment if they are to be competitive in today's …

Recent Advances In Engineering Design: Theory And Practice, Andrew J. Moskalik

Masters Theses

In the last few years, industry and academia have focused greater attention on the area o f engineering design. Manufacturers have implemented new design methods such as concurrent engineering and design for manufacture, and academia has increased research in design-related issues. This paper will attempt to summarize the recent advances, both scholarly and industrial, relating to the field of design. I will examine new methodologies and supporting tools for the design process, both in use and under research. This paper will cover concurrent engineering, design for manufacture, quality methods, design theory research, computer-aided design, expert systems, analysis programs, manufacturing, and …

An Empirical Study Of Just-In-Time And Total Quality Management Principles Implementation In Manufacturing Firms In The U.S., Loknath Sriparavastu

Masters Theses

Literature in vogue points out that, in the last decade, American manufacturing companies came a long way in their renewed emphasis on the quality process. Justin- Time (JIT) and Total Quality Management (TQM) are the two magical phrases that are being frequently used in almost all the articles published on quality and productivity. Nevertheless, the literature does not provide any satisfactory explanation as to how JIT and TQM principles are implemented in the manufacturing industries.

This research, through a nationwide empirical survey, analyzed the effects of JIT and TQM strategies implementation. Survey results showed that implementing both JIT and TQM …

Particle Dynamics Modeling Of Vibrating Granular Beds, Yidan Lan

Dissertations

Particle dynamics modeling is done to study the behavior of granular beds subjected to vibrations imposed by a plane boundary which oscillates sinusoidally about a zero mean speed. Significant differences between the lower and higher shaking acceleration regions are found for the granular temperature and solids fraction depth profiles, which characterize the effectiveness of the boundary in fluidizing the beds. When higher accelerations are applied, the temperature is maximum at the vibrating floor and attenuates through the depth, while the solids fraction profiles exhibit a maximum at some intermediate depth. At lower acceleration values, most of the mass is located …

Adaptive Nonlinear Control Using Fuzzy Logic And Neural Networks, Shu-Chieh Chang

Dissertations

The problem of adaptive nonlinear control, i.e. the control of nonlinear dynamic systems with unknown parameters, is considered. Current techniques usually assume that either the control system is linearizable or the type of nonlinearity is known. This results in poor control quality for many practical problems. Moreover, the control system design becomes too complex for a practicing engineer. The objective of this thesis is to provide a practical, systematic approach for solving the problem of identification and control of nonlinear systems with unknown parameters, when the explicit linear parametrization is either unknown or impossible.

Fuzzy logic (FL) and neural networks …

Kinematic And Kinetic Analysis Of Geneva Mechanisms And Their Applications To Synchronization Of Motion, Bijan Sepahpour

Theses

Geneva mechanisms have been used for generating intermittent motion for use in indexing and packaging operations. Due to their popularity, cost effectiveness and diversified applications in industry, it is desirable to optimize their design.

Optimization techniques and modifications have been developed to provide long life, trouble-free high-speed indexing and intermittent motion while minimizing the undesirable inherent dynamic characteristics of this class of mechanisms.

A general information base of the motion characteristics and types of geneva mechanisms available has been established. Development of the full spectrum of the required equations, generation of the normalized values of critical design parameters along with …

An Interactive Computer Graphics Based Off-Line Avail Programming Environment For Coordinate Measuring Machines, Nayanesh B. Bhandutia

Theses

Productivity can be increased by providing computer aided off-line program development environment to operate direct computer controlled Coordinate Measuring Machines (CMM). Such an environment not only results in reduced operational downtime of the CMM but also eliminates the need for the operators to learn and debug the complicated CMM programming language.

An application software was developed to provide a computer based graphical environment for on-the-screen CMM inspection simulation and AVAIL part program development. A comprehensive, menu driven front-end was developed as a foundation for this software. Algorithms were designed and coded to read and interpret CAD software part design information …

Automatic Feature Extraction From Conventional Cad Model To Support Feature-Based Design Approach For The Sheet Metal Stamping Industries, Dipak P. Thakar

Theses

Despite the continuing improvement in computer aided design (CAD) systems and improvements in computer aided manufacturing (CAM), the process planning activity has still not been completely integrated into the CAD/CAM cycle. Particularly in sheet metal stamping industries human interpretation of CAD data is required to extract the geometry and technological information of a component. As a result most CAD systems are used as advanced drafting and drawing management tools by designers. Thus the responsibility for interpreting the design data required for extracting the manufacturing part features still resides with the process planner. Which has increase possibilities of entering errors with …

Remediation Of Contaminated Sites Using Hot Gas Injection, Sanjay Jayabal

Theses

Remediation of contaminated subsurface sites at lower cost and time than currently used technologies are being demonstrated for a systems concept using new technology developed at the Hazardous Substance Management Research Center at New Jersey Institute of Technology. A technique for pneumatic fracture is employed to "open" subsurface passages to enhance vacuum extraction of contaminants. Economical and environmentally sound destruction of these contaminants is then accomplished using catalytic oxidation followed by scrubbing to remove air pollutants. The hot gas from this phase of the process is then injected into the subsurface formation after being used to preheat the fuel/air mixture …

Implementation Of Continuous Flow Manufacturing In United States Industries, Rohit P. Patel

Theses

Continuous Flow Manufacturing (CFM) is one of the key strategies to enable the United States industries to adapt to any volume increase and rapidly changing requirements of the market place. CFM is an on-going analysis and improvement activity used to optimize the efficiency, effectiveness and flexibility of any process. The two basic goals of CFM are to reduce cycle time to less than customer order leadtime and to eliminate inefficiencies from the overall manufacturing processes.

The thesis will describe reasons for the scarcity of CFM in United States industries. The methodology applied was a detailed six page questionnaire sent to …

Dynamic Friction Measurement, Atif Aly

Theses

The friction force between two bodies sliding at constant relative velocity is a function of their relative velocity. Under conditions of time-variable relative velocity, the instantaneous friction is a function not only of the instantaneous velocity but also the velocity history. An understanding of the resulting dynamic friction function will allow for the design of control systems where velocity is time-varying, oscillatory andoften contained in a relatively small region centered around zero amplitude. Within the control system, a portion of the control force can be implemented to effectively counteract the friction present and allow for precise motion control.

In this …

An Integrated Approach To Implement Iso 9000 Series Standards To United States Manufacturing Industry, Jatin N. Amin

Theses

Implementation of ISO 9000 series quality system standards to the U.S. manufacturing industry is discussed by developing a generic model for implementation. In recent past, quality became a prime performance issue to formulate strategy to improve market share and profit for U.S. manufacturing industry. Many companies seeks for ISO 9000 registration. Manufacturing industry and other industries as well, are facing numerous problems in implementing ISO 9000 quality system standards. At present, about 400 U.S. companies have gained certification under this standard.

In this work an attempt has been made, to highlight problems which are most likely to be critical to …

Museum Committee Meeting May 1994, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Revised by-laws Museum Studies master student Evaluation of Building Integrity

Automation Of The Electrostatic Aerosol Classifier And The Continuous Flow Cloud Diffusion Chamber, Daron W. Dryer

Opportunities for Undergraduate Research Experience Program (OURE)

Analyzing cloud condensation nuclei through the use of a Continuous Flow Thermal Diffusion Cloud Chamber (CFD) and an Electrostatic Aerosol Classifier (EAC) can be very time consuming. An alternative to manually monitoring these devices is to automate the equipment, thus freeing personnel for other research as well increasing CCN data collection.

Automation of the EAC will be carried out by digital command through the use of a Quick Basic program. This program will be run from an IBM personal computer outfitted with a digital input/output board.

RS-485 Standard will also be incorporated into the Quick Basic program in order to …

A Computer Graphic Teaching Aid For The Synthesis Of Four-Bar Linkages, Sew K. Woon

Opportunities for Undergraduate Research Experience Program (OURE)

This project involves developing software for the use as a teaching tool in the classroom. The "four-bar linkage mechanism", often used in kinematic movement, is the main subject

The software provides a working environment to perform a graphical synthesis of a four- bar linkage to move one of the links through three specified positions in the plane. The construction process is facilitated by the built in kinematic intelligence so that the student can quickly and easily visualize the process. The construction lines are dynamically updated as the free parameters in the design are modified. This is particularly beneficial because it …

Fabrication Of Composite Laminates With Embedded Pizo-Ceramic Sensors And Actuators, Todd Nelson Kelsheimer

Opportunities for Undergraduate Research Experience Program (OURE)

The purpose of the research project is to investigate the methods for embedding pizo-ceramic sensors and actuators in a composite ( a fiber reinforced epoxy matrix). The importance of these sensors and actuators is vital in controlling the vibration and excessive strain on a structure causing fatigue or failure. With the control of these instabilities by the actuator, proper performance of the structure is achieved. Most sensors and actuators are surface mounted because (1) The sensor can pick up the greatest strain on the surface of a structure. (2) The actuator can create a stronger moment to counter balance the …