Mechanical Engineering Commons^™

Simple Fall Criteria For Mems Sensors: Data Analysis And Sensor Concept, Alwathiqbellah Ibrahim, Mohammad I. Younis

Mechanical Engineering Faculty Scholarship

This paper presents a new and simple fall detection concept based on detailed experimental data of human falling and the activities of daily living (ADLs). Establishing appropriate fall algorithms compatible with MEMS sensors requires detailed data on falls and ADLs that indicate clearly the variations of the kinematics at the possible sensor node location on the human body, such as hip, head, and chest. Currently, there is a lack of data on the exact direction and magnitude of each acceleration component associated with these node locations. This is crucial for MEMS structures, which have inertia elements very close to the …

Early Damage State Criterion From A Fault-Seeded Helicopter Gear Using Acoustic Emission And Neural Networks, Rudy L. Baum

Doctoral Dissertations and Master's Theses

In response to five failures since 2008 of the tail gearbox of multiple models of Sikorsky's H-60 helicopter, acoustic emission (AE) data collected from a rotating gearbox test stand at the Naval Air Station in Patuxtent River, MD, was used to monitor the initiation and propagation of a flaw from an electro-discharge machined (EDM) notch seeded on the face of a gear tooth. A period of testing was considered which spanned ~300,000 seconds or ~83 hours and culminates to a damage state such that a flaw has initiated on both ends of the EDM notch. AE data was analyzed for …

Elastic Energy Absorption Via Compliant Corrugations, Sean S. Tolman

Theses and Dissertations

Elastic absorption of kinetic energy and distribution of impact forces are required in many applications. This may be achieved through the use of compliant corrugations. An innovative padding concept is investigated for such applications. Also, recent attention given to the potential for using origami in engineering applications may provide new corrugation configurations that are advantageous for energy absorption and force distribution. This work explores three areas related to these concepts.First, the parameters of a compliant, corrugated padding concept are investigated using Finite Element Analyses (FEA) and physical testing. The shape of the corrugation cross section is explored as well as …

Automated Landing Site Determination For Unmanned Rotocraft Surveillance Applications, Justin Keith Mackay

Theses and Dissertations

Unmanned air vehicles have been increasing in their autonomous capabilities. This research furthers these capabilities by focusing on the automation of landing site determination for rotorcraft in urban environments. Automated landing saves energy and allows the aircraft to choose areas that are safe for people and the aircraft. Two methods are used to gather information about the terrain of potential landing sites. One method is 3D reconstruction from multiple camera images. The other method uses a range sensor to reconstruct the terrain. Both of these methods create an inertial terrain map of the environment in the form of a point …

Design Of A Passive Ankle Prosthesis With Powered Push-Off Using A Cam Timing Mechanism, Jacob J. Rice

Master's Theses (2009 -)

This thesis presents the design and simulation results of the CamWalk, a novel passive prosthetic ankle that has mechanical behavior similar to that for a natural ankle. The CamWalk uses a compression spring network that allows coupling between two degrees of freedom; one for translation along the leg and another for rotation about the ankle joint. When walking, potential energy from the person's weight is stored in the spring network in deflection along the leg. The energy is released by the network as rotation of the foot. The amount of translational work that is converted to rotational work about the …

Modeling, Analysis, And Verification Of A Weld-Breaking Mechanism For Automatic Circuit Recloser Applications, Brian Korves

Master's Theses (2009 -)

The automatic circuit recloser (ACR) is responsible for protecting electrical distribution grids in the event that high voltage power lines come in contact with ground. In order to prevent damage, ACRs break the electrical continuity of the circuit through the use of a vacuum interrupter and a weld breaking mechanism. Vacuum interrupters consist of two metallic contacts in an air-tight ceramic housing. Due to the electrical interactions that take place during the interruption process, unintended welds are formed between the contacts. These welds have the ability to impede or completely stop the interruption process, thus rendering the ACR inoperable. In …

Design And Verification Of A Compact Variable Stiffness Actuator With A Very Large Range Of Stiffness, Daniel Garces

Master's Theses (2009 -)

Current conventional robots require high stiffness joints to provide absolute positioning accuracy in free space which also causes problems when operating in constrained space. To circumvent these problems, Variable Stiffness Actuators (VSAs) can be used to vary their stiffness to suit the task being performed. A new VSA was designed to provide a very large range of stiffness in a compact size. The Arched Flexure VSA uses a cantilevered beam acting as the flexure with a variable point of contact. It allows the joint to have continuous variable stiffness, have zero stiffness for a small range of motion, and rapid …

Determination Of A Predictive Stiffness Model For A 1 Dof Human Inspired Robotic Joint, Michael Boyarsky

Master's Theses (2009 -)

In order to facilitate more natural and intuitive interaction for human users, robots need to move in a more human-like manner as compared to current robots. This change would enable humans to better anticipate robot movements (which would allow humans to better avoid collisions if necessary) and also improve safety in the context of a collision between a robot and a human. The goal of this thesis was to analyze experimental data of human motion to gain an understanding of how human motion and robot motion differ. From this understanding, a neuro-motor model (NMM) of a human elbow (previously established …

A Position Analysis Of Coupled Spherical Mechanisms In Action Origami, Landen A. Bowen, L. A. Baxter, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Origami has been previously utilized in design to create deployable systems. Action origami, origami designed to move, has the ability to deploy to a larger state and have motion in the deployed state. The majority of action origami achieves motion through coupled systems of spherical mechanisms. An origami vertex, the point at which folds converge, is shown to be equivalent to a spherical change-point mechanism. A position analysis of an origami vertex is presented, resulting in a relationship between input and output angles as well as the path of the coupler link. A method for analyzing coupled systems of repeated …

Integration Of Microwave And Thermographic Ndt Methods For Corrosion Detection, Dustin F. Pieper, Kristen M. Donnell, Mohammad Tayeb Ahmad Ghasr, Edward C. Kinzel

Electrical and Computer Engineering Faculty Research & Creative Works

Infrastructure health monitoring is an important issue in the transportation industry. For the case of cement-based structures in particular, detection of corrosion on reinforcing steel bars (rebar) is an ongoing problem for aging infrastructure. There have been a number of techniques that have shown promise in this area including microwave nondestructive testing (NDT) and thermography. Thermography is quite advantageous as it is an established method, and can be utilized for large inspection areas with intuitive results. Typical heat sources include induction heating and flash lamps, but these are not without drawbacks. Microwave nondestructive testing has also been successful at detecting …

Energy Conservation By Intermittently Recirculating And Aerating An Aquaponics System With An Airlift, Bjorg Magnea Olafs

Doctoral Dissertations and Master's Theses

An airlift device providing aeration and circulation was designed to reduce electrical power requirements for aquaponics by eliminating the need for a water pump. The airlift performed better than predicted and achieved water flow rates of 10 L/min at 25 °C, in comparison to the theoretical design performance 2.65 L/min.

Koi (Cyprinus carpio) and sweet basil (Ocimum basilicum) were cultured for five weeks in two identical aquaponics systems. The system was located indoors and consisted of a fish tank, a sump tank, and a soil-free growth media bed under artificial lighting. The total water volume in each system was 230 …

Investigation Of Potential Benefits Of Revising Exception 1 Under Florida Building Code, Energy Conservation, Section 101.4.7.1.1 Duct Sealing Upon Equipment Replacement, Florida Solar Energy Center, Janet Mcilvaine

FSEC Energy Research Center®

Section 101.4.7.1.1, Duct sealing upon equipment replacement (Mandatory), of the 2012 Supplement to the Florida Building Code, Energy Conservation went into effect briefly in 2013. The new section required sealing of accessible ducts at the time of HVAC equipment replacement. Exception #1 however, eliminates the requirement for ducts in conditioned space, and by doing so, effectively eliminates the sealing requirement for building cavities in conditioned space that are used as air distribution paths. However, test results show that these building cavities are often connected to adjacent unconditioned spaces, in effect they are not really in the conditioned space because they …

Analysis Of Different Techniques For Improving Performance Of Flat Plate Solar Collectors For Fruits Drying, Godfrey Mbabaye

Tanzania Journal of Engineering and Technology (TJET)

Fruits drying had become a broader technology in fruits and vegetables value addition. The technology is reported to be a promising way of drying without incurring higher cost but its adaptation has not been feasible in rural areas. Solar dryers have been developed but its poor performance limits its applicability. In this study, several techniques for modifications of traditional solar collector were addressed. It was observed that, varying collector designs in different techniques, a range of collector performances can be archived. The research shows that, collector efficiency can be improved by 9.6% when employing double duct counter flow compared to …

Investigating The Potential Of Residential District Energy, Nelson Fumo, Vicente Bortone, Juan Zambrano, Aleyani Zambrano

Mechanical Engineering Faculty Publications and Presentations

The International District Energy Association claims that district energy: improve energy efficiency, enhanced environmental protection, fuel flexibility, ease of operation and maintenance, reliability, comfort and convenience for customers, decreased life-cycle costs, decreased building capital costs, and improved architectural design flexibility. In the U.S.A. most of the installed district energy systems are found in buildings such as colleges and universities, healthcare installations, government installations, airports and community utilities, as well as industry. All these applications have proved the advantages of district energy. However, for typical neighborhoods in small cities in the U.S.A., the dispersion of the dwelling imposes additional challenges to …

Vehicle Multi-Pass Rut Volume And Mobility Power Study, William W. Barbour

Pursuit - The Journal of Undergraduate Research at The University of Tennessee

This paper presents the relationship between applied power by a wheeled vehicle to soil and the rutting effects. Specifically, a strong positive relationship was found between cumulative applied power and total rut volume across multiple passes by the vehicle over the same tracks. Field-testing was conducted using a high-mobility multi-purpose wheeled vehicle (HMMWV) and two distinct soil types. Sensors on the vehicle measured torque and angular velocity of each of the four wheels, from which applied power was calculated. A rut profile meter was used to document the shape of the rut after set numbers of passes and this profile …

Initial Testing Of A Unitary Hvac System Advanced Control Module, Florida Solar Energy Center, Richard Raustad

FSEC Energy Research Center®

Testing of a unitary HVAC system advanced control module and the results.

Are Undergraduate Gpa And General Gre Percentiles Valid Predictors Of Student Performance In An Engineering Graduate Program?, Larry L. Howell, Carl D. Sorenson, Matthew R. Jones

Faculty Publications

While both subjective measures and quantitative metrics play an important role in admissions decisions, quantitative metrics are amenable to critical analysis using the tools of academic analytics. The hypotheses that motivated this study are: 1. Can an applicant’s undergraduate grade point average (UGPA) and scores on the Graduate Records Examinations (GRE) be used to accurately predict the performance of the applicant in a graduate mechanical engineering program? 2. Is a single construct based on these quantitative predictive metrics a valuable tool in efficiently making admissions decisions? This study analyzed the relationship between quantitative predictive metrics, available at the time of …

Curvature Induced Phase Stability Of An Intensely Heated Liquid, Kiran Sasikumar, Zhi Liang, David G. Cahill, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

We Use Non-Equilibrium Molecular Dynamics Simulations to Study the Heat Transfer Around Intensely Heated Solid Nanoparticles Immersed in a Model Lennard-Jones Fluid. We Focus Our Studies on the Role of the Nanoparticle Curvature on the Liquid Phase Stability under Steady-State Heating. for Small Nanoparticles We Observe a Stable Liquid Phase Near the Nanoparticle Surface, Which Can Be at a Temperature Well above the Boiling Point. Furthermore, for Particles with Radius Smaller Than a Critical Radius of 2 Nm We Do Not Observe Formation of Vapor Even above the Critical Temperature. Instead, We Report the Existence of a Stable Fluid Region …

A Study Of Slipper And Rail Wear Interaction At Low Speed, Greg V. Cavallaro

Theses and Dissertations

The wear research presented in the work consists of results gathered from adapting a FEM based on a Holloman High Speed Test Track (HHSTT) mission executed in January 2008. The FEM consists of a VascoMax slipper sliding on a stationary AISI-1080 steel rail. The slipper is slid along the rail at speeds of 20 m/s and 40 m/s with complementary vertical velocities of -0.079 m/s and -0.059 m/s, respectively. The surface roughness caused by features such as asperities and valleys of the materials, is simulated in this model by five asperities, 1 micron to 5 microns on the rail and …

Minimization Of The Effects Of Secondary Reactions On Turbine Film Cooling In A Fuel Rich Environment, Andrew T. Shewhart

Theses and Dissertations

The demand for increased thrust, higher engine efficiency, and reduced fuel consumption has increased the turbine inlet temperature and pressure in modern gas turbine engines. The outcome of these higher temperatures and pressures is the potential for unconsumed radical species to enter the turbine. Because modern cooling schemes for turbine blades involve injecting cool, oxygen rich air adjacent to the surface, the potential for reaction with radicals in the mainstream flow and augmented heat transfer to the blade arises. This study evaluated various configurations of multiple cylindrical rows of cooling holes in terms of both heat release and effective downstream …

Organizing A Student Poster Session In An Asee Section Conference, Steve Eugene Watkins, Les Kinsler, Julia L. Morse, Douglas R. Carroll

Electrical and Computer Engineering Faculty Research & Creative Works

Student poster sessions at conferences can be valuable experiences for undergraduate and graduate students and can enrich the conference program for all participants. Student poster presentations beyond the local campus can provide additional experience in professional communication (especially in preparing succinct abstracts and in effective visual design), can prepare students for future conference participations, and can facilitate student-faculty interaction. Several issues exist when including student poster sessions in engineering education conferences. How can the content of posters be related to an engineering education theme? How are communication principles of audience and purpose incorporated into the session guidelines and review process? …

Helicopters As A Theme In A Machine Design Course, Devin Turner, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

Helicopters as a Theme in Teaching Machine Design A machine design course is required in most undergraduate mechanical engineering curricula. This course generally covers an introduction to mechanical engineering design, a review of materials engineering, a review of mechanics of materials (shear force and bending moment diagrams, stress and strain analysis, deflection and stiffness analysis of beams, columns, etc.),models for failure due to static loading and variable fatigue, and then presents (in somewhat arbitrary order) the design of specific mechanical elements: shafts, fasteners, springs, bearings, gears, flexible elements such as belts, chain, and wire rope, clutches, brakes, couplings, etc. For …

Machine Design Experiments Using Mechanical Springs To Foster Discovery Learning, Peter William Malak, Mark L. Nagurka

Mechanical Engineering Faculty Research and Publications

Machine Design Experiments Using Mechanical Springs to Foster Discover Learning For the typical undergraduate engineering student the topic of mechanical springs is introduced and discussed in several courses. A first exposure may be in a physics course, where springs are presented as idealized mechanical energy storage components. Springs store potential energy,complementing masses that store kinetic energy and dampers that are resistive and offer no energy storage capability. In an electrical circuit course, springs are often presented as the analog of either capacitors or inductors, depending on which analogy is used. For mechanical engineering students, springs are a core component studied …

Induction Phone Charger Case, Dante Eley, Nicholas Mason, Laurence Pringle

Mechanical Engineering Senior Theses

This report discusses the project of creating a manual charging phone case for smartphones by means of electromagnetic induction. In today's world, smartphones are being used on the go more often, creating an increased demand for battery life. The capacity of current batteries cannot keep up with the constant usage of data in such activities as emailing, social media, apps, and more. We developed an efficient, ergonomic, and aesthetically pleasing phone case that can manually charge a smartphone without an electrical outlet, but by means of electromagnetic induction. This product would target two main demographics: business people who are constantly …

Phonon Confinement Using Spirally Designed Elastic Resonators In Discrete Continuum, Sourav Banerjee, Raiz U. Ahmed

Faculty Publications

Periodic and chiral orientation of microstructures, here we call phononic crystals, have extraordinary capabilities to facilitate the innovative design of new generation metamaterials. Periodic arrangements of phononic crystals are capable of opening portals of non-passing, non-dispersive mechanical waves. Defying conventional design of regular periodicity, in this paper spirally periodic but chiral orientation of resonators are envisioned. Dynamics of the spirally connected resonators and the acoustic wave propagation through the spirally connected multiple local resonators are studied using fundamental physics. In present study the spiral systems with local resonators are assumed to be discrete media immersed in fluid. In this paper …

Uncertainty Quantification Driven Predictive Multi-Scale Model For Synthesis Of Mycotoxins, Sourav Banerjee, Gabriel A. Terejanu, Anindya Chanda

Faculty Publications

Many toxic molds synthesize and release an array of poisons, termed mycotoxins that have an enormous impact on human health, agriculture and economy [1]. These molds contaminate our buildings, indoor air and crops, cause life threatening human and animal diseases and reduce agricultural output [2]. In order to design appropriate approaches to minimize the detrimental effects of these fungi, it is essential to develop diagnostic methodologies that can rapidly and accurately determine based on fungal strains and their growth patterns, the extent of mycotoxin mediated damage caused to the environment.Here we developed a novel multi-scale predictive mathematical model that could …

Stress Analysis For Chip Scale Packages With Embedded Active Devices Under Thermal Cycling, Hyunwook Yeo

Dissertations and Theses

One of the main challenges in the electronics manufacturing and packaging development is how to integrate more functions inside the same or even smaller size. To meet the demand for higher integration, the interest toward passive and active component embedding has been increasing during the past few years. One of the main reasons for the growing interest toward embedded active components, in addition to demand for higher packaging density, is the need for better electrical performance of the component assemblies. However, it is little known how embedded IC and passives affect the reliability of IC packaging.

Solder joints have been …

Assessment Of Energy Efficient Methods Of Indoor Humidity Control For Florida Building Commission Research, Florida Solar Energy Center, Charles Withers, Jr.

FSEC Energy Research Center®

This research project was conducted with the primary objective to identify approaches and technologies which can achieve energy-efficient latent cooling in light of code requirements that may increase overall ventilation rates in new Florida homes. This report covers the work of two primary efforts of completing a literature review and testing a few space conditioning methods in a mechanically ventilated building. Results from a literature review provide a list of various approaches to managing the latent load in homes with emphasis on energy efficiency and cost-effectiveness. In addition to a literature review, controlled experiments using four different approaches to space …

The Poverty Crusher, Rob Golterman, Brian Hammond, Thien-Ryan Le, Arvin Lie

Mechanical Engineering Senior Theses

The Poverty Crusher team built a human-powered rock breaking device for the women in Nepal who make $1.50 - $3 per day crushing rocks. A prototype jaw-type rock crusher was designed and built over a period of several months. However, the device was unable to break rocks due to excessive bending in the connection points of the frame and in the crushing faces. Improvements were suggested for the next prototype, which include increasing the second moment of inertia of the crushing faces, using a welded frame, and generally decreasing the cost and weight of the device.

Swing Wing Aerial Drone (Swad), Chris Barton, Robert Gomez, Matt Kochalko, Kyle Nakagaki

Mechanical Engineering Senior Theses

Drones are unmanned aerial vehicles that have a variety of different applications in the field. Drones are very helpful for first responders such as firefighters, police, and even ranchers and large landowners. Most drones have a fixed wing. This report will show the design, construction, and fluid dynamic testing of a drone that has multiple wing positions. These modes are the straight wing position and swept back position. This design will change the flight profile of the plane, allowing for the user to launch at a faster speed and the glider to get to the desired location faster. Once the …