Mechanical Engineering Commons^™

An Analysis Of The Study Of Mechanical Properties And Microstructural Relationship Of Hsla Steels Used In Ship Hulls, Htay Aung

World Maritime University Dissertations

No abstract provided.

Functional Disaster Resistant Buildings, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

Natural disasters, such as hurricanes, floods, tornados, tsunami and earthquakes, are becoming a greater problem as they destroy lives, homes, businesses and the natural environment. Such disasters can happen with little or no warning, leaving hundreds or even thousands of people without medical services, potable water, sanitation, communications and electrical services for up to several weeks. One proactive strategy to minimize this type of destruction and disruption to lives is the implementation of disaster-resistant buildings that are energy efficient, fortified to the latest codes, and incorporate renewable energy systems. This approach uses the best energy-efficient buildings, fortified to the latest …

Problems And Solutions: Training Disaster Organizations On The Use Of Pv, Florida Solar Energy Center, William Young

FSEC Energy Research Center®

In 1992, the Florida Solar Energy Center (FSEC) and Sandia National Laboratories (SNL) assisted the University of Miami Field Epidemiology Survey Team (FEST) with photovoltaic systems to power temporary medical clinics after Hurricane Andrew struck south Dade County. At that time, it became apparent that there were no educational materials prepared for disaster relief or emergency management personnel on the use of photovoltaic (PV) to supply electrical power in response to a disaster. This need prompted FSEC to create an education program to develop awareness and train organizations on the proper use of PV in disasters. Since then, FSEC has …

Structuring Emperical Methods For Reuse And Efficiency In Product Development Processes, Marshall Edwin Bare

Theses and Dissertations

Product development requires that engineers have the ability to predict product performance. When product performance involves complex physics and natural phenomena, mathematical models are often insufficient to provide accurate predictions. Engineering companies compensate for this deficiency by testing prototypes to obtain empirical data that can be used in place of predictive models. The purpose of this work is to provide techniques and methods for efficient use of empirical methods in product development processes. Empirical methods involve the design and creation of prototype hardware and the testing of that hardware in controlled environments. Empirical methods represent a complete product development sub-cycle …

The Piezoresistive Effect In Microflexures, Gary K. Johns

Theses and Dissertations

The objective of this research is to present a new model for predicting the piezoresistive effect in microflexures experiencing bending stresses. A linear model describing piezoresistivity exists for members in pure tension and compression. Extensions of this model to more complex loading conditions do not match experimental results. An accurate model of piezoresistivity in complex loading conditions would expand the design possibilities of piezoresistive devices. A new model to predict piezoresistive effects in tension, compression, and more complex loading conditions is proposed. The focus of this research is to verify a unidirectional form of this proposed model for microflexures in …

Windmill Documentary, Timothy David Stoltenburg

Honors Capstones

Capstone submitted as a graduation requirement for the BSU Honors Program.

Grid-Connected Photovoltaic System Design Review And Approval, Florida Solar Energy Center, James Dunlop

FSEC Energy Research Center®

This document provides details of operations and procedures for the approval of grid-connected photovoltaic (PV) system designs and documentation conducted by the Florida Solar Energy Center. The principal goal of this process is to help ensure the safety and quality of installed PV systems, and provides an assurance to installers, consumers and financiers that approved designs meet accepted codes and industry practices, and are accompanied by a complete System Manual that meets the minimum requirements outlined in this document.

Test Method For Photovoltaic Module Ratings, Florida Solar Energy Center, Kevin Lynn

FSEC Energy Research Center®

This document describes the testing and reporting requirements for certification and labeling of photovoltaic modules (PV) for their power ratings. The test methods and procedures chosen for this purpose are based on consensus standards of relevant committees of the Institute of Electrical and Electronic Engineers (IEEE), the American Society for Testing and Materials (ASTM), or the International Electrotechnical Commission (IEC).

Executive Summary: Evaluation Of The Impact Of Vacant Home Space Conditioning Strategies On Summer Relative Humidity, Energy, And Peak Load; Phase Ii, Florida Solar Energy Center, James Cummings

FSEC Energy Research Center®

The Vacant Home Space Conditioning Study was sponsored by Florida Power & Light (FPL) as part of its Conservation R&D Program and carried out by the Florida Solar Energy Center (FSEC). In the US, about one in four retiree "snowbirds" make Florida their destination to escape the northern cold. Snowbird residents number more than 900,000 in Florida during the winter. In some counties of FPL's territory these seasonal residents compose up to 15% of the population (Shih, 1981). This pattern of seasonal occupancy creates a need for space conditioning guidelines for vacant homes to avoid mold problems while minimizing both …

Branch Detonation Of A Pulse Detonation Engine With Flash Vaporized Jp-8, John David Slack

Theses and Dissertations

Pulse Detonation Engines (PDE) operating on liquid hydrocarbon fuels are limited to operating frequencies of 35 Hz due to long ignition times from a low energy ignition sources. This study shows ignition time of JP-8 can be nearly eliminated by igniting a thrust tube using a secondary detonation. A counter flow heat exchanger attached to a thrust tube utilized waste heat from the detonation process to heat JP-8 to supercritical conditions. The fuel flash vaporized when injected into the air stream of the engine. A detonation was produced by a spark in a 5 cm diameter, 1.37 m long tube. …

Single-Sided Crash Cushion System, John D. Reid, John R. Rohde, Dean L. Sicking

Department of Mechanical and Materials Engineering: Faculty Publications

A single-sided crash attenuation cushion system having an impact head and three stage energy absorption mechanism. The energy absorbing mechanism has a mandrel for deforming thin-walled tubes in a controlled collapse to absorb impact forces from a colliding vehicle. The third stage of the absorption mechanism includes an additional deformable compressible tube between the fixed-object hazard and the thin walled tubes.

A Torque Based Power Input Model For Friction Stir Welding, Jefferson W. Pew

Theses and Dissertations

For decades models have been developed for predicting the size of the weld nugget and heat affected zones in fusion welded structures. The basis for these models is the welding heat input, which is fairly well understood for most arc welding processes. However, this traditional approach is not as straightforward for Friction Stir Welding (FSW). To date, there is no definitive relationship to quantify the heat input for FSW. An important step to establish a heat input model is to identify how FSW process parameters affect weld power. This study details the relationship between FSW process parameters and torque for …

A Dynamic Workflow Framework For Mass Customization Using Web Service And Autonomous Agent Technologies, Daniel J. Karpowitz

Theses and Dissertations

Custom software development and maintenance is one of the key expenses associated with developing automated systems for mass customization. This paper presents a method for reducing the risk associated with this expense by developing a flexible environment for determining and executing dynamic workflow paths. Strategies for developing an autonomous agent-based framework and for identifying and creating web services for specific process tasks are presented. The proposed methods are outlined in two different case studies to illustrate the approach for both a generic process with complex workflow paths and a more specific sequential engineering process.

College Of Engineering Senior Design Competition Fall 2006, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

Large 3-D Deflection And Force Analysis Of Lateral Torsional Buckled Beams, Robert Parley Chase

Theses and Dissertations

This thesis presents research on the force and deflection behavior of beams with rectangular cross-sections undergoing lateral torsional buckling. The large 3-D deflection path of buckling beam tips was closely approximated by circular arcs in two planes. A new chain algorithm element was created from pseudo-rigid-body segments and used in a chain calculation that accurately predicted the force deflection relationship of beams with large 3-D deflections.

Solar Dhw Storage Tanks And Systems, Florida Solar Energy Center

FSEC Energy Research Center®

Water is by far the most common storage medium in solar domestic hot water systems. Rock storage is another method of sensible heat storage, but is not generally used in systems that are exclusively DHW. Storage of heat in solutions of phase-changing salts is extremely rare in DHW systems and therefore is not discussed.

Multi-Sensor Fusion Based Control For Autonomous Operations: Rendezvous And Docking Of Spacecraft, Jonathan Bryan Mcdonald

Mechanical and Aerospace Engineering Theses - Archive

The project considers the problem of motion synchronization of free flying robotic spacecraft and serviceable floating objects in space. The synchronization maneuvers are based on sample and hold nonlinear translational and attitude control laws. GPS pseudorange signals and a vision based sensor unit are modeled to give position measurements; position and velocity estimates are extracted from the measurements based on Extended Kalman Filter models. A sensor data fusion algorithm in the form of a Federated Extended Kalman Filter is implemented that blends the estimates of the individual filters into a global estimate. Nonlinear simulations where a Pursuer spacecraft attempted to …

Enhancement Of Pool Boiling Heat Transfer Using Thermally-Conductive Microporous Coating Techniques, Joo Han Kim

Mechanical and Aerospace Engineering Dissertations - Archive

The present research is an experimental study of the enhancement of boiling heat transfer using microporous coating techniques. The current research is divided into four major phases. During the first phase, the effects of different metal particle sizes in the coating compound for thermally non-conductive microporous coating on pool boiling performance of refrigerants and water are investigated. The test surfaces, solid copper blocks with 1-cm² base, were tested at atmospheric pressure in saturated FC-72, R-123, and water. Results showed that the surface treatment by non-conductive microporous coating significantly enhanced both nucleate boiling and critical heat flux of all three refrigerants. …

Flexible Microfluidic Circuit With Embedded In-Plane Valve, Srikar C. Paruchuri

Mechanical and Aerospace Engineering Theses - Archive

Recent developments in Microfluidic systems have demonstrated many potential applications related to biology, chemistry and medical sciences. Fluidic manipulation with precise volume control is a basic function in these systems, and microvalves play an important role in control and delivery of the fluid sample. One of the key issues in such valve design is to make large membrane deflections compared to the channel dimension. This thesis reports a flexible microfluidic chip with embedded in-plane valves for fluid manipulation. Silicone elastomer (Polydimethylsiloxane - PDMS) is one of the most suitable materials to fabricate microvalve membranes, because of its low Young's modulus, …

Computer-Aided Patient Specific Treatment Planning Of Cryosurgery For Breast Cancer, Junkyu Jung

Mechanical and Aerospace Engineering Theses - Archive

Cryosurgery, which is to destroy tumors by use of localized freezing, is an emerging treatment modality for breast cancer as the size of detectable tumor becomes smaller due to more frequent use of various diagnostic imaging including MRI, CT and mammogram. Although general surgical guideline has been developed and its effectiveness has been demonstrated, cryosurgical protocol should be adjusted for a given patient to accommodate patient-specific variations including tumor size, location and geometry of patient's breast. In this study, a computerized treatment planning tool was developed to aid surgeons to determine surgical parameters considering patient specific diagnostic information. This tool …

Freezing-Induced Microstructural Changes Of Collagen Scaffolds, Jeffrey David Miller

Mechanical and Aerospace Engineering Theses - Archive

Understanding the effects of freezing on the functional properties of tissues is critical to cryopreservation of native and artificial tissues, and prognosis after cryotherapies. Although investigations have been performed to correlate macroscopic properties such as mechanical properties with freezing parameters, the effects are typically tissue-type dependent and no physical understanding is available to explain these effects. Since the mechanical and optical properties of a tissue are based on the characteristics of its extracellular matrix (ECM), understanding and quantifying these changes could assist in predicting the response a tissue will have to freezing under different circumstances. In this study, the microstructural …

Optimization Of The Tool Path In A Robotic Environment, Mukund Venkatachari Narasimhan

Mechanical and Aerospace Engineering Dissertations - Archive

The rising costs and demand coupled with shrinking energy generating resources has triggered the need for optimum use of energy resources, minimizing the overhead costs and maximizing the profits. Robots have been long touted as a fit replacement of human labor force in manufacturing sectors. Slowly there is increased presence of robots in automobile and electronic industries. Typically they are used for welding, painting, ironing, assembly, pick and place, inspection, and testing. Mass production, fulfilling the ever increasing demand, can be accomplished by robots because of their precision, speed of operation and high endurance capabilities. This dissertation comprises of two …

Finite Element Modeling Of Carbon Nanotube Reinforced Polymer Composites And Evaluating Its Thermal Conductivities, Raghuram Basavanahalli

Mechanical and Aerospace Engineering Theses - Archive

High thermal conductivity of carbon nanotubes has motivated us to study and understand the thermal mechanisms in nanocomposites. Though several theoretical models predict a high thermal conductivity for CNT reinforced polymer composites, the experimental validation are not so encouraging. A finite element model of MWNT reinforced nanocomposite is developed based on continuum mechanics approach. The finite element model is a representative volume element (RVE) with single MWNT inclusion. The inclusion is modeled based on the continuum model of MWNT as effective solid fiber [22].The interface resistance between the nanotube and the matrix material is modeled using thermal contact elements. The …

Structural Analysis Of Fiber Reinforced Composite Materials, Cesar Augusto Rojas

Mechanical and Aerospace Engineering Theses - Archive

A study of fiber reinforced composite structures is conducted .This study includes laminate analysis, analysis of laminated composite beams and parametric study of composite beams. Finite element analysis for each beam model is conducted to verify the results obtained by analytical model. The analysis of the laminated beams in this study covers: 1. beam with a solid rectangular cross-section subjected to a transverse load 2. beam with a I-section under bending 3. beam with a squared tubular section under bending 4. beam with truss section under bending One of the principal purposes of this thesis is to create a user …

Titanium Alloyed With Boron, Seshacharyulu Tamirisakandala, Daniel B. Miracle, Raghavan Srinivasan, Jay S. Gunasekera

Mechanical and Materials Engineering Faculty Publications

Small additions of boron to conventional titanium alloys have been found to produce significant changes to the microstructures and associated properties. Grain refinement and improved strength and stiffness are first-order effects, which lead to possibilities for developing novel and affordable processing methodologies and to enhance performance over conventional titanium alloys. In this article, we introduce this new class of titanium alloys and describe unique formability benefits achieved via engineering microstructures.

An Experimental Comparison Of Dimensional And Strength Characteristics Of American And Chinese Manufactured Fasteners, Michael Bailey Stroup

All-Inclusive List of Electronic Theses and Dissertations

This research investigated the quality and strength characteristics ofboth American and Chinese manufactured fasteners. The purpose of this research was to determine if there is a significant statistical difference between both manufacturers dimensional and tensile strength characteristics as to the American National Standards Institute's specified tolerances. The researcher selected the independent samples t-test to analyze the raw data collected from the experiment. SPSS 13.0 statistical analysis software was used to determine the degree of correlation between the independent variables: fastener dimensions, and ultimate tensile strengths. The researcher involved utilizing a calibrated micrometer that was capable to producing measurements to the …

Correlation Of Numerical Ability And Quality Technician Best Performers In Manufacturing Quality Control Applications, Charles Wesley Shelton

All-Inclusive List of Electronic Theses and Dissertations

The occupation of Quality Technician has many duties requiring numerical operations. Business and industry place considerable emphasis on numerical ability when evaluating the performance of a Quality Technician. In this study, the numerical ability and performance classification of Quality Technicians were analyzed using a correlation analysis. lll A single case study was used to investigate this relationship. A modified Delphi Method was used to determine characteristics of a Quality Technician. Quality Technicians were evaluated by their direct supervisor and completed a standardized numerical ability test. The evaluations by the supervisor were used to classify each technician based on their performance. …

Reliability-Based Optimization Of Fiber-Reinforced Polymer Composite Bridge Deck Panels, Michel D. Thompson, Christopher D. Eamon, Masoud Rais-Rohani

Civil and Environmental Engineering Faculty Research Publications

A reliability-based optimization (RBO) procedure is developed and applied to minimize the weight of eight fiber-reinforced polymer composite bridge deck panel configurations. The method utilizes interlinked finite element, optimization, and reliability analysis procedures to solve the weight minimization problem with a deterministic strength constraint and two probabilistic deflection constraints. Panels are composed of an upper face plate, lower face plate, and a grid of interior stiffeners. Different panel depths and stiffener layouts are considered. Sensitivity analyses are conducted to identify significant design and random variables. Optimization design variables are panel component ply thicknesses while random variables include load and material …

Design And Optimization Of Heat Spreaders And Selection Of Fan In Laptop, Kranthi Kumar Manne Sambaiah

Mechanical and Aerospace Engineering Theses - Archive

Technical advancements lead to the need for faster processors and reduced sizes in electronic systems. The urge for faster and compact systems leads to two major problems. Firstly over heating of chips which degrade the chip performance and secondly formation of heat spots on the surface which makes the user uncomfortable. Thermal management engineers, as a result have a major challenge in improving the cooling systems. In this research project simulation using the thermal modeling tool selected is Icepak. The prototype model of the laptop is designed, boundary conditions are applied and analysis is done. The results so obtained in …

A Simple Numerical Method Of Cycle Jumps For Cyclically Loaded Structures, D. Cojocaru, Anette M. Karlsson

Mechanical Engineering Faculty Publications

A method for accelerated numerical simulations of structures subjected to cyclic loading is investigated. Of particular interest is a class of structures where the structural properties evolve with time. The proposed method is based on conducting detailed finite element analysis for a set of cycles to establish a trend line, extrapolating the trend line spanning many cycles, and use the extrapolated state as initial state for additional FEA simulations. This includes a control function that automatically monitors the length of the cycle jump to ensure a realistic solution. We compare the proposed method to a reference calculation, where all incremental …