Engineering Commons^™

Computer Aided Finite Element Stress Analysis Of A Three Dimension Mandibular Bone Model Using I-Deas Software, Yixiong Xu

Theses

A three dimensional model of half of the mandibular bone, with 487 tetrahedra elements and 1,047 nodes, is established and analyzed by means of I-DEAS software. The masseter muscle is assumed to be 15° deviation from y-axis, and the Umetani boundary conditions are allowed to be varied. A 337 lb force was applied along the midline of the mandible to simulate a trauma force caused by the auto accident. The maximum principal stress is 18,400 psi and the minimum principal stress is -1,340 psi. Depending on the experimental results of dispalcement and maximum principal stress, the conclusions are drawn: 1) …

Heat Resistance Measurements With The Portable Calorimeter Box, Philipp G. Mohr

Theses

The heat resistance of wall section materials has been investigated under laboratory conditions, but reliable measurements in-situ with non-steady weather conditions are not yet available. The portable calorimeter box is designed to make field measurements to test the thermal performance of building envelopes. The experimental setup and the equipment for thermal measurements are described, as well as the computer program for data reduction. The characteristics of the portable calorimeter box and the problems of non-controllable test conditions have been investigated.

Forty experiments were completed. Sixteen preliminary experiments investigated problems associated with insufficient setups; such as a short duration, only partly …

Forward Kinematics Solution Of A Special Class Of General Stewart Platforms, Jian Li

Theses

A Stewart platform is a fully parallel, six-degree-of-freedom manipulator mechanism. A platform manipulator has a fixed platform acting as base, a mobile platform on which end-effector is mounted, and in-parallel kinematics chains (legs) between the two platforms. Although some direct position kinematics solutions for Stewart platforms of simplified geometry have been represented, to the best of our knowledge, no close-form direct kinematics solution for the general Stewart platform is available yet.

A common feature of six-degree-of-freedom Stewart platform of simplified geometry is the use of pairs of concentric ball joints. Due to inevitable manufacturing and assembly errors, practically there are …

Development Of A Model For An Objective Minimum Resolvable Temperature Difference Characterization Of An Infrared Camera, Christine Issa Mourad

Theses

The parameter almost universally adopted by the infrared community for describing the overall performance of a thermal imaging camera is the minimum resolvable temperature difference. Unfortunately, this criterion is subjectively determined by a group of observers and as a consequence significantly varying results can be obtained at different times. This project describes work on an approach which ultimately aims to replace the observers by a computer-aided installation that simulates the human process by which the MRTD is estimated. The simulation is based on a direct measurement of signal to noise ratio in the image of the target and a determination …

A Direct Method For Surface Structure Recovering Based On Uoff, Ping Lin

Theses

The unified optical flow field (UOFF) theory which can be used for estimating motion and recovering surface structure was recently established in [9, 10]. The direct method developed in [2, 3, 4, 6, 7] does not need to explicitly solve the optical flow field and to find feature correspondence. Based on the UOFF, a direct method in space domain is developed to reconstruct the curved surface structure characterized by an Nth degree polynomial equation from a pair of stereo images. The initial work on this new method was reported in [8, 11].

In this study, I basically work on simulation …

Graphics Interfaced Computer Automated Process Planning, Ajit Nimbvikar

Theses

The work is based on the manufacturing of gears in a Job Shop type production plant. The topic is divided into three sections. 1. design, 2. graphics, and 3. process planning and analysis. A program is developed using Fortran for the iterative design procedure. With basic inputs, the program provides the design of gears with dimensions. During the procedure, the user has to intervene to specify some codes for the selection of materials and other parameters. Second section deals with the graphics utility. It provides a drawing of the gear with dimensions according to the input obtained from the design …

Torque And Current Response Due To Singularity Changes Of Induction Machine Slip, Jessie G. Orpilla

Theses

Recognizing that the prime purpose of the 3 phase induction motor is to deliver torque with minimum line current. This thesis studies the torque as well as the current response produced by the singularity changes in the induction machine slip. It is desirable that the torque to be maximized for a given value of line current at the corresponding load slip.

This thesis analyzes the torque and current response, when a slip at no-load is changed to a unit-step, Qu(t), a unit-impulse, Qδ(t), a pulse characterized by Q[u(t)-u(t-T)], a unit-ramp, Qt, and a sinusoidal, Qsint, slip. The responses are analyzed …

Translation Of Images On The Hypercube Using Leaf Codes, Bhavesh Patel

Theses

Image processing is used for manipulation of pictorial images. Image analysis applications are typically characterized by the need to process large quantities of image data. Some of the important transformations or operations which are car¬ried out by image processing systems are translation, scaling, superposition and rotation. Algorithms have been developed to carry out these transformations on image regions represented by quadtrees. Gargantini introduced an algorithm to translate an image region represented by a linear quadtree or leafcodes. A linear quadtree is a space efficient data structure used for storing digital images. Ziavras et.al. have proposed a modification of Gargantini's algorithm …

Development Of A Composite User Equilibrium And System Optimization Assignment Model, Kimberly M. Stump

Theses

The Urban Transportation Modeling System (UTMS) is a set of procedures used by transportation planners to predict the volume of traffic that will flow through a network, and how the traffic is routed. This paper will focus on the final component of UTMS, traffic assignment, which assigns the traffic flows to actual routes in the network.

In this paper, two composite models which model both User Equilibrium and System Optimal assignments are presented. The composite models are solved using the GAMS (General Algebraic Modeling System) software, a powerful mathematical programming tool. The first model was based on Beckman's Formulation, (Beckman, …

Trouble Shooting In Plastic Injection Molding Machines, Zafar Kamal

Theses

The purpose of this thesis is to find the solution of those problems which occur during plastic injection molding process. Molding cycle problem analysis is an important field in plastic injection process. It is very necessary to catch the problems during operation. Therefore on the basis of research trouble shooting criteria is prepared.

Good quality control is an essential feature for finding any sort of fault. Quality control is associated with each and every step of operation to maintain the required shape and surface finishing.

Most of the molding problems are solved by varying the machine conditions and by changing …

Simulation Study For The Effect Of Dependencies In Queueing Systems, Yitao Bai

Theses

Few theoretical results have been obtained in the literature for the effects of dependencies between random variables on the performance of queueing systems. This thesis aims at investigating this issue via simulation. Several dependencies are studied in detail, including dependencies between interarrival times, between interarrival time and service time, between service times and dependencies between different stages in networks of queues. We define several classes of dependent random variables and study their correlation coefficients, then we apply them to single and multiple station service systems. Comparisons with the independent case, for which the explicit form solution are available, are made …

Three Dimensional Magnetic Field Sensors And Array In Bicmos Technology, Bingda Wang

Theses

This thesis presents new designs of three dimensional magnetic field sensors in BiCMOS technology. The detailed design of the merged structure device by common diffusion and the high gain transduction circuit are presented. The merged structure has the advantage of less area, less external contacts and less parasitic capacitance. Cross-sensitivity is also eliminated by employing the merged structure. Three active on-chip loads are introduced to improve the sensitivity. The SPICE simulation results show that when a relative change in current ΔI/I is 0.001, about 13.6 mV and 8.5mV can be detected at the output in X(or Y) and Z directions, …

Timed Petri Net Simulation Of Flexible Manufacturing Systems, Yan Chen

Theses

Standard Petri nets have been used to model and analyze Flexible Manufacturing Systems. The timed Petri net, which can incorporate the time delay associated with manufacturing events, provides additional information about real time behavior of practical systems. The Timed Petri Net Simulation Tool, a highly interactive graphical tool, is applied to simulate the modeled flexible manufacturing systems. Timed Petri net models are experimented with. Machine utilization data and throughput are obtained. Analysis of the results shows that the system performance can be optimized by choosing proper parameters.

A Sign-To-Speech Translation System, Koka Veera Raghava Rao

School of Computing: Dissertations, Theses, and Student Research

This thesis describes sign-to-speech translation using neural networks. Sign language translation is an interesting but difficult problem for which neural network techniques seem promising because of their ability to adjust to the user's hand movements, which is not possible to do by most other techniques. However, even using neural networks and artificial sign languages, the translation is hard, and the best-known system, that of Fels & Hinton (1993), is capable of translating only 66 root words and 203 words including their conjugations. This research improves their results to 790 root signs and 2718 words including their conjugations while preserving a …

A Successive Approximation Algorithm To Solve Motion Planning Problems, Cheng-Ming Chang

Theses

A successive approximation algorithm is presented to solve motion planning problems and optimal control problems. A motion planning problem is included in an optimal control problem and due to the heavily nonlinear and coulped differential equations describing the dynamics of the manipulator and several constraints imposed on the system, few efficient methods exist to solve this kind of problems.

The successive approximation algorithm can decompose the global nonlinear problem into several nonlinear subproblems and each subproblem is solved by the nonlinear programming method with a highly convergent rate. Because the limited constraints and variables are included in each subproblem and …

The Thermal Model Of The Rat Under Hemorrhagic Shock Hypothermia With Microwave Intervention, Liu Zhe

Theses

A whole body thermal model simulating heat distribution and temperature regulation in rats during hemorrhagic shock and during post-shock microwave core rewarming period was developed. An electrical circuit was used to simulate the thermal system and a software named PSpice? was used to analyze the circuit. The temperature regulation as the result of the simulation is demonstrated to match the measured temperature histories of rats in hemorrhagic shock and the microwave rewarming experiment.

The blood pressure drop and cardiac output decrease were considered in the simulation and the so called "set point temperature" was investigated in the model. Linear decrease …

Reverse Engineering : An Evaluation Of Contact Technology And Application In Manufacturing Systems, Shailesh V. Jadhav

Theses

There are many instances where one-of-a-kind parts, such as prototypes or custom-built parts, need to be reproduced. When a Computer Aided Design (CAD) of an existing part is not available, reverse engineering is involved in recreation of such part. Currently, geometric measurements from the surface of a prototype are extracted manually and sent to a CAD system. It is typically time consuming, tedious, and potentially a source of error. This study outlines a methodology, for the development of a CAD model, rapid prototype, and subsequently manufacturing of the part. The method developed uses a contact technique to extract 2-D or …

Modification Of Wear Testing Machine And Study Of Wear Resistance, Ning Li

Theses

In this work a modification of a wear testing machine has been done by designing a new loading mechanism and redesigning different components for a new roller-on-roller wear testing machine. A new loading mechanism containing gearbox frame and load cell assembly have been designed, manufactured and assembled. A pusher of the pushing mechanism is redesigned for better durability. Existing bearing support was redesigned and replaced. All new units of the wear testing machine were lined up and assembled with the machine. Finite element stress analysis for designed frame in the load mechanism was performed by using the Integrate Design Engineering …

Computer Aided Manufacturing For Production Environment, Biren K. Parikh

Theses

Investments in new technology like Computer Aided Manufacturing (CAM) increased in the past few years because of the foreign competition in the world market as well as on the home ground. Improper investment in CAM and CIM resulted in the "Islands of Automation" instead of an integrated system. These "Islands of Automation" have created new problems for production planning and factory communication.

The objective of the thesis is to develop the methodology to selection and implementation of the CAM system in the production environment. It is to be noted that a CAM system is part of the overall CIM implementation, …

The Research, Design And Production Of Cortical Bone Pins And Screws For The Fixation Of Broken Bones In The Hand And Wrist, Ronald P. Holland

Opportunities for Undergraduate Research Experience Program (OURE)

Investigators at the University of Missouri at Rolla have entered into a joint venture with surgeons at Saint Louis University Hospital to develop a superior method of fixing broken bones of the human hand and wrist. This method involves the production of pins and screws from human cortical bone which will be used to fix broken bones for healing. The cortical bone fasteners will provide many advantages to the currently used metal fasteners. To date, prototype fasteners have been developed and are pending mechanical testing as a result of this undergraduate research project. Results of this project potentially include a …

Influence Of Pattern Geometry And Pouring Temperature On Fluidity In The Expendable Pattern Casting Process, Diego Rodriguez Risco

Opportunities for Undergraduate Research Experience Program (OURE)

This report is an extension of the paper "Influence of Pattern Geometry and other Process Parameters on Mold Filling in the Aluminum EPC Process", by Yuan Sun, Hai-Lung Tsai and Donald R. Askeland (2). The increase in fluidity in the expendable pattern casting (EPC) process with pattern perimeter, volume to surface area (V/A) ratio, and pouring temperature was studied for a 700°C-900°C temperature range and for both aluminum and cast iron.

Solidification Modeling Of Centrifugal Casting, Stephen M. Lane

Opportunities for Undergraduate Research Experience Program (OURE)

This paper describes the methodology used to estimate the solidification time of castings produced by processes in which normal thermal analysis cannot be used, such as centrifugal casting. This methodology utilizes the relationship between microstructure, in particular secondary dendrite arm spacing (SDAS), and freezing time. Using this method it is shown that position within the casting and casting geometry affect the SDAS and freezing time. However, the SDAS did not vary across the wall section due to differences in filling pattern compared to sand casting. Further research is necessary to determine filling pattern effects on microstructure.

Analysis Of Turnability For A Three Terminal Microwave Network, Michael J. Bahr

Opportunities for Undergraduate Research Experience Program (OURE)

Three-terminal microwave networks can be shown to exhibit qualities that would make them desirable to be used as multiple terminal devices. Using microwave theory, where instantaneous voltage is a function of position on the line, this situation will be examined. These devices use the interference principle of propagating waves as the basis of their characteristics. This investigation will probe a three- terminal microwave network with one input and two output. This configuration acts similar to a splitter where the outputs may be controlled. These three terminals, plus manipulation of the lengths of each side, actually makes this a four terminal …

Tape Casting For Lead Zirconate Titanate (Pzt) Multilayer Composites, Jane L. Cochran

Opportunities for Undergraduate Research Experience Program (OURE)

Tape casting is a process for making thin flat ceramic pieces by using a scraping blade or "doctor blade" to evenly coat a smooth surface with a slip[ 1 ]. The slip is a mixture of powder, solvent, binder, and other organics which result in a paint like consistency after they are mixed.

The tapes is cast into thicknesses ranging from 1 to 50 mils on a smooth surface , which is usually made of Mylar, and left to dry.

Once the tape has dried it can be cut into several different shapes and sizes, and then fired to form …

Dynamics Of Ultrashort Pulse Generation And Amplification In Dye Lasers, Shuanghua Jiang

Dissertations and Theses

The dynamics of ultrashort pulse generation and amplification in dye lasers is studied in this dissertation. In particular, we have developed general semiclassical models for ultrashort pulse dye laser amplifiers and oscillators. These models start from Maxwell's equation for the electric field and density matrix equations for the active laser medium. A finite coherence time or phase memory time of the molecular wave functions, a finite vibrational relaxation time for the lower electronic state of the dye laser transition, an isotropic molecular orientational distribution, and an arbitrary pump polarization are all taken into account. Based on these models, specific topics …

Vortex Developments Over An Accelerated Airfoil At High Angles Of Attack, Jacopo A. Frigerio

Opportunities for Undergraduate Research Experience Program (OURE)

Proper control of unsteady separated flow developments over the lifting surfaces of an aircraft may prove to be an effective method of enhancing aerodynamic lift and producing better aircraft performance. Due to the complexity of unsteady flow separation and subsequent flow developments, experimental exploration and observation are essential in providing a source for comparison and verification with theoretical and computational models. In light of these motivations, a new experimental system that is capable of generating wide of range of unsteady flow histories has been developed and employed to visualize flow developments over an airfoil in accelerated-decelerated motion. The paper presents …

Motorized Throttle Plate, John D. Crawford

Opportunities for Undergraduate Research Experience Program (OURE)

The objective of this project was to develop a throttle plate mechanism that can be used to simulate transient engine operation. This throttle plate was designed so as to regulate the quantity of air flow entering a Port Fuel Injected (PFI) spark ignition engine prior to the combustion of the fuel-air mixture. The throttle plate is linked to a data acquisition system in order to study the port fuel injection characteristics of the fuel-air mixture. This data acquisition system links the throttle plate angular position information to data obtained using a nonintrusive laser based diagnostic technique, therefore enabling the study …

Fiber Optic Fabry-Perot Sensors For Smart Structures, Thomas K. Edmondson

Opportunities for Undergraduate Research Experience Program (OURE)

Optical fiber sensors promise to play a large role in the development of smart structures which have the ability to continuously monitor themselves for internal and external structural deformation, and even actively change shape. This investigation studies one such sensor based on a fiber optic Fabry-Perot interferometer, which detects the displacement between two points of a material. Sensor theory and construction are discussed, and the tools used to analyze sensor output are developed. The interferometer is then tested by attaching it to a large cantilever beam which is deflected to produce strain. This experimental data is then used to determine …

Experimental Investigation On The Longitudinal Stability Of A P51 Mustang Aircraft Model, Erich Fitzpatrick

Opportunities for Undergraduate Research Experience Program (OURE)

This project involved the development of a test model of the P-51 Mustang aircraft and an experimental investigation of its stability. The model was developed to investigate the influence of the main horizontal tail parameters ( tail incidence, position of c.g., stabilizer moment arm,etc.)on the pitching moment around the aircraft’s center of gravity. To accomplish such a task, a test model was designed and fabricated with flat plate and airfoil wing configurations. The tail incidence of the flat plate stabilizer is adjustable over the entire range of positive and negative angles. A rechargeable, electric motor mounted in the fuselage adjusts …

Catalysis Of Charcoal Emissions, James M. Horak

Opportunities for Undergraduate Research Experience Program (OURE)

This paper is about the development of a system to reduce the emissions of charcoal kilns with the catalyst from automotive catalytic converters. This device, called the charcoal kiln emissions oxidizer (CKEO), was designed and fabricated to meet the goal of a cost effective means to reduce the carbon monoxide and hydrocarbon emissions from charcoal kilns. Testing of the CKEO was never carried out as a test site could not be secured by this writing. The need for the CKEO, the theory behind it, and a procedure to test it are presented.