Mechanical Engineering Commons^™

Thickness-Shear And Thickness-Twist Vibrations Of Circular At-Cut Quartz Resonators, Huijing He, Jiashi Yang, Qing Jiang

Department of Mechanical and Materials Engineering: Faculty Publications

Exact solutions for free vibration frequencies and modes are obtained for thickness-shear and thickness-twist vibrations of unelectroded circular AT-cut quartz plates governed by the two-dimensional scalar differential equation derived by Tiersten and Smythe. Comparisons are made with experimental results and the widely-used perturbation solution by Tiersten and Smythe under the assumption of weak in-plane anisotropy. Our solution is found to be much closer to the experimental results than the perturbation solution . For the frequency of the fundamental thickness- shear mode, the error of the perturbation method is 0.4549%, significant in resonator applications.

Experimental Assessment Of The Impact Of Asymptomatic Gas Emboli On The Vessel Wall, Linxia Gu, Eric L. Cutler

Department of Mechanical and Materials Engineering: Faculty Publications

Quantitative evaluation of shear stress in the vessel wall due to the presence of asymptomatic gas emboli is lacking. The goal of this work was to assess the impact of chronic asymptomatic gas emboli on the risk of atherosclerosis through a custom-built cardiovascular flow simulator. Gas bubbles were created by forced air from a syringe pump. The influences of embolism injection rate, pulse rate, and time-averaged flow rate on the wall mean shear stress were investigated at resting and elevated heart rate conditions. The recorded pressure and volumetric flow rate from 24 experimental settings with four repetitions each were used …

Organic Solar Cells Based On High Dielectric Constant Materials: An Approach To Increase Efficiency, Khalil Jumah Tawfiq Hamam

Dissertations

The efficiency of organic solar cells still lags behind inorganic solar cells due to their low dielectric constant which results in a weakly screened columbic attraction between the photogenerated electron-hole system, therefore the probability of charge separating is low. Having an organic material with a high dielectric constant could be the solution to get separated charges or at least weakly bounded electron-hole pairs. Therefore, high dielectric constant materials have been investigated and studied by measuring modified metal-phthalocyanine (MePc) and polyaniline in pellets and thin films. The dielectric constant was investigated as a function of temperature and frequency in the range …

Wind And Hydroelectric Power Simulation For The Dc House Project, Randy Lormand, Christopher Goloskie

Electrical Engineering

This project details the design and integration of a wind and hydroelectric power simulation system in correlation with the DC House Project. The simulator uses variable speed drives to rotate a DC motor which then drives a generator to produce output. This output is then regulated using a DC to DC converter which holds the voltage level constant making it easier to interface with other power sources for the house. The test results indicate that the simulator will be able to produce two separate power outputs that will provide at least 70 Watts of power in the acceptable speed range …

Swing Human Powered Generator: For The Dc House Project, Juan Vicente Avelar, Juan Jose Galindo, Juan Pramyr Ramos

Electrical Engineering

The Play Park Human Powered Generator project addresses various ways of generating power. More specifically, this project entails the design and construction of the Swing Power Generator to provide electrical power from mechanical energy. The swing generator will eventually be used as part of the human-powered generators utilized in the DC House project.

A swing generator prototype was built for this project, which demonstrates the feasibility of its use for electrical power source. Detailed design and construction of the swing generator is presented in this report along with results from hardware testing.

Intuity Sleeve Redesign, Maxwell Arnold, Brittany Kinkade, Dominic Nicoletti

Mechanical Engineering

No abstract provided.

Exploration Station Kidshake Table, Jeremy Duhe, Philip Hopkins, Matt Ostiguy, Samantha Weiner

Mechanical Engineering

The KIDShake Table is an all mechanical earthquake shake table sponsored by the Exploration Station Children's Museum of Grover Beach. This interactive exhibit has two working mechanisms, a hand crank and pull rope, that provide two axis movement for knocking down block structures. This table was built and designed for a target age of 10 years.

Dedion Axle Senior Project, Nick Schraan, Mark Shushnar, William Swenson, Ramy Tall

Mechanical Engineering

The sponsor, EV Grid Inc. is a company looking to the future with the development of a vehicle to grid infrastructure. The vehicle in development is a Ford E-250 Van which had been converted to electric drive with a front motor, rear drive layout. The sponsor wanted to move the electric motor to the rear and develop an axle to support this change. By eliminating the driveshaft, a more efficient use of battery space could be utilized. The goal of this project is to design and fabricate a prototype deDion rear axle which incorporates a system of drive components that …

Architectural Engineering Earthquake Shake Table, Garrett Gudgel, John Whitmer, Brandan Williams

Mechanical Engineering

The Architectural Engineering Department at California Polytechnic State University, San Luis Obispo, owns and operates a single-axis earthquake shake table that previously was only capable of basic wave motion. After implementing a computer based interface to the existing system, Mechanical Engineering student seniors were able to create control algorithms that can take existing or user created acceleration data from earthquakes as well as any user defined position data to be accurately run on the earthquake shake table.

Adaptive Floor Hockey Device, Chris Gaul, Ricardo Gaytan, Matt Spaulding, Shannon Brant

Mechanical Engineering

Sean is a young boy living with ataxic cerebral palsy. Ataxic cerebral

palsy affects Sean’s balance and coordination, so he uses a walker to

increase his mobility. Sean would like to play Special Olympics Floor

Hockey but his walker prevents him from participating. The goal of this

Senior project was to develop a device to be attached to his previous

walker to allow Sean to play floor hockey in the least restrictive

environment possible. The Adaptive Floor Hockey Device is the product

we designed to satisfy this need.

School Van Access In Nepal, Edgar Corona, Humberto Maldonado, Josh Schiesl

Mechanical Engineering

A need has been identified by a school in Nepal intended for children with Cerebral Palsy, called Sathi Sansar, to develop a more effective solution to loading and unloading students onto the school’s Toyota HiAce van. Currently, a combination of the driver, parents and teachers manually help the students on and off the van. However, this task has proven to be both laborious and time consuming for all parties involved. A solution to this problem needs to be designed and one is currently being developed by a team of engineering students from California Polytechnic State University-San Luis Obispo and Katmandu …

Mercedes-Benz Oil Level Monitor, Emmanuel Camacho, Jonathan Manriquez, James Young

Mechanical Engineering

The purpose of this project is to develop an engine oil level monitoring system that will replace the current dipstick method during vehicle testing for Mercedes-Benz Research and Development North America, Inc. (MBRDNA). Currently, MBRDNA test drivers check the engine oil level twice a day after two eight hour shifts each day. To measure the oil level, the driver parks on a level surface, waits five minutes for the oil to cool, and then manually checks the oil level with the dipstick. The goal of this project is to have a reliable, physical, working prototype that MBRDNA can use for …

Bocce Ball Launcher: An Adaptive Bocce Ball Device, Jake Deschamps, Megan Hughes, Thomas Lynch

Mechanical Engineering

This report details the adaptive bocce launching device created by Team B.A.L.L. and theprocess of designing, building and testing it. The final design was a wirelessly controlled pneumatic catapult capable of propelling a bocce ball such that it would land fifteen feet away and roll the length of the wheelchair accessible bocce courts located at the Colony Park Community Center in Atascadero. A wide variety of users are supported because the system is controlled by a single button which can be actuated by the user’s hand, forearm, head or anything else they are able to move. The catapult allows the …

Beach Wheelchair Project, Rory Aronson, Joshua Marcum, Samuel Coyne, Alex Hayes, Alexa Colburn, Max Hessel, Benedikt Strauss, Marvin Rimmele, Marco Pietsch

Mechanical Engineering

The Beach Wheelchair, Sandcrawler, is a machine intended to help give people with disabilities the full beach experience. The non-profit organization Bridge II Sports sponsored this project, and tasked us with developing the design and fabricating a prototype. This chair has several features including a linkage mechanism that raises and lowers a chair relative to an external frame, hand crank drive with Gates Carbondrive belt and sprockets, buoyant Wheeleez balloon tires, and much more.

Rebounder Fatigue Test Machine, Caroline Reeves, Will Robertson, Ethan Flory

Mechanical Engineering

JumpSport, a company that designs and sells trampolines and trampoline accessories, has sponsored this senior project team to design, build, and test a trampoline fatigue test machine. The machine must simulate a person jumping on the trampoline to test the life of JumpSport’s fitness trampolines and kids’ trampolines. Partway through the design process, the objectives were altered and this senior project team was tasked with merging with another Cal Poly senior project group to create an all-inclusive test machine to accommodate both full-trampoline testing and individual bungee cord testing.

The final design is centered on a slider crank linkage driven …

Human Powered Helicopter: Spars, Jason Addy, Sterling Fuentes, Graham Garvin, Kenneth Girardin, Lipski Timonthy, Daniel Logue

Industrial and Manufacturing Engineering

Abstract

Neal Saiki, a Cal Poly alumnus, donated a human powered helicopter to the Cal Poly Aircraft Design and Construction Club in Fall Quarter 2012. To achieve the requirements of the Igor Sikorsky Human Powered Helicopter Competition, this senior project was tasked with reducing the weight of the load-bearing spars without changing geometry.

The aluminum spars were replaced with carbon fiber. The spars were designed to maintain the bending and torsional stiffnesses. Twelve sections of carbon fiber tubes ranging from 8 to 12 ft in length and 2" to 3" in inner diameter were made using pre-preg carbon fiber wrapped …

S&G Metal Fab Battery Tray, Matthew Nartatez

Industrial and Manufacturing Engineering

This report was written for the design of a battery tray and manufacturing process for S&G Metal Fab. The manufacturing steps of how to process the sheet metal to create the product are defined and documented in this report. This project began with constraints given by S&G and were all accomplished using coursework knowledge obtained as a manufacturing engineer student at Cal Poly San Luis Obispo. This report mainly covers parameters regarding the cutting, bending and, deforming of sheet metal to acquire the desired shapes and sizes. It also analyzes the costs that are associated with these processes and material. …

Animatronic Robot Development Using Pulse Width Modulation Microcontroller Programming, Laura Mcdonald

Liberal Arts and Engineering Studies

No abstract provided.

Me-Em Enewsbrief, June 2013, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Training Future Designers: A Study On The Role Of Physical Models, Vimal Viswanathan, Julie Linsey

Faculty Publications, Mechanical Engineering

Physical Models in Engineering Education: Making Tomorrow’s Designers Creative Innovation and creativity are two essential qualities for tomorrow’s designers. In order to nurture these skills in designers, our engineering curricula need to include more hands-on training. In recent times, many engineering educators have recognized the importance of hands-on training in engineering curriculum. Allowing students to build and test their own physical models and learn from their mistakes can be a very effective way of teaching. Recent studies have shown that physical models play a very important role in design innovation and creativity. Building and testing such models can lead designers …

Evaluation Of Novel High-Density Emg Feedback Parameters On The Spatial Distribution Of Trapezius Muscle Activity, Brecca M. Gaffney

Electronic Theses and Dissertations

Each year, 17.9% of adults working in a computer-dominated work environment develop an episode of chronic neck and shoulder pain. An effective treatment method for chronic pain is postural correction through therapist. The understanding of the relation between cervicoscapular posture and trapezius muscle activity is not fully understood because the anatomy of the scapula is not accessible for direct observation. Until recently, the spatial distribution of trapezius muscle activity could not be measured due to the limitation in size of detection zone in traditional bipolar electrodes. The primary goal of postural correction when treating cases of chronic neck and shoulder …

Zone Of Intrusion For Permanent 9.1-Degree Single Slope Concrete Barriers, Cale J. Stolle

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Three WDOT 9.1-degree single-slope concrete barriers, with top heights of 36 in. (914 mm), 42 in. (1,067 mm), and 56 in. (1,422 mm) (Standard 14B32), were analyzed for Zone of Intrusion (ZOI)’ and working width using nonlinear finite element analysis (FEA). Tire-barrier friction, vehicle-barrier friction, barrier stiffness, mesh size, tire deflation, and suspension component failures were all found to have effects on simulation results. The zone of intrusion and working width were evaluated for each barrier under varying tire deflation and suspension failure conditions and determined to have a maximum value of 12.2 in. (310 mm) for the front fender …

Design And Development Of A Stair Ascension Assistive Device For Transfemoral Amputees, Casey Michael Barbarino

Master's Theses

Transfemoral amputees around the world experience increased difficulty in climbing stairs due to lack of muscle, balance, and other factors. The loss of a lower limb greatly diminishes the amount of natural force generation provided that is necessary to propel oneself up stairs. This study investigated possible solutions to the problem of stair ascension for transfemoral amputees by the means of designing and developing an externally attachable device to a prosthesis. The number of amputations from military service has greatly increased since 2008, which shows there is a clear need for assistive devices (Wenke, Krueger, & Ficke, 2012). With the …

Design, Fabrication, And Testing Of An Emr Based Orbital Debris Impact Testing Platform, Jeffrey J. Maniglia Jr.

Master's Theses

This paper describes the changes made from Cal Poly’s initial railgun system, the Mk. 1 railgun, to the Mk. 1.1 system, as well as the design, fabrication, and testing of a newer and larger Mk. 2 railgun system. The Mk. 1.1 system is developed as a more efficient alteration of the original Mk. 1 system, but is found to be defective due to hardware deficiencies and failure, as well as unforeseen efficiency losses. A Mk. 2 system is developed and built around donated hardware from the Naval Postgraduate School. The Mk. 2 system strove to implement an efficient, augmented, electromagnetic …

Compressive Response Of Polycrystalline Nicomnga High-Temperature Meta-Magnetic Shape Memory Alloys, H. E. Karaca, A. S. Turabi, B. Basaran, A. K. Pathak, I. Dubenko, N. Ali, Y. I. Chumlyakov, P. Li

Mechanical Engineering Faculty Publications

The effects of the addition of quaternary element, Co, to polycrystalline NiMnGa alloys on their magnetic and shape memory properties have been investigated. NiCoMnGa polycrystalline alloys have been found to demonstrate good shape memory and superelasticity behavior under compression at temperatures greater than 100 °C with about 3% transformation strain and low-temperature hysteresis. It is also possible to train the material to demonstrate a large two-way shape memory effect.

Fluid-Structure Interactions With Flexible And Rigid Bodies, David J. Daily

Theses and Dissertations

Fluid structure interactions occur to some extent in nearly every type of fluid flow. Understanding how structures interact with fluids and visa-versa is of vital importance in many engineering applications. The purpose of this research is to explore how fluids interact with flexible and rigid structures. A computational model was used to model the fluid structure interactions of vibrating synthetic vocal folds. The model simulated the coupling of the fluid and solid domains using a fluid-structure interface boundary condition. The fluid domain used a slightly compressible flow solver to allow for the possibility of acoustic coupling with the subglottal geometry …

Performance Of Solid Oxide Iron-Air Battery Operated At 550°C, Xuan Zhao, Yunhui Gong, Xue Li, Nansheng Xu, Kevin Huang

Faculty Publications

“Metal-air” batteries have garnered much attention in recent years due to their high intrinsic specific energy and use of inexhaustible and storage-free oxygen source -air- for the “metal-oxygen” reaction. In this study, we report theperformance of a new type of all solid-state “iron-air” battery operated at 550°C. The results show that CeO₂ nanoparticles incorporated into the Fe-Fe₃O₄ redox-couple can improve the specific energy (Wh/kg) and round trip efficiency by 15% and 29%, respectively, over the baseline Fe-Fe₃O₄ battery. Use of supported Fe-Fe₃O₄ nanoparticles as the redox couple can increase the …

A Multiobjective Optimization Method For Collaborative Products With Application To Engineering-Based Poverty Alleviation, Nicholas Scott Wasley

Theses and Dissertations

Collaborative products are created by combining components from two or more products to result in a new product that performs previously unattainable tasks. The resulting reduction in cost, weight, and size of a set of products needed to perform a set of functions makes collaborative products useful in the developing world. In this thesis, multiobjective optimization is used to design a set of products for optimal individual and collaborative performance. This is introduced through a nine step method which simultaneously optimizes multiple products both individually and collaboratively. The method searches through multiple complex design spaces while dealing with various trade-offs …

Micro Modeling Study Of Cathode/Electrolyte Interfacial Stresses For Solid Oxide Fuel Cells, Xinfang Jin, Xingjian Xue

Faculty Publications

Delamination of the cathode/electrolyte interface is an important degradation phenomenon in solid oxide fuel cells (SOFCs). While the thermal stress has been widely recognized as one of the major reasons for such delamination failures, the role of chemical stress does not receive too much attention. In this paper, a micro-model is developed to study the cathode/electrolyte interfacial stresses, coupling oxygen ion transport process with structural mechanics. Results indicate that the distributions of chemical stress are very complicated at the cathode/electrolyte interface and show different patterns from those of thermal stress. The maximum principal stresses take place at the cathode/electrolyte interface …

Studies On Structure And Property Of Polymer-Based Nano-Composite Materials, Yun Zhai

LSU New Orleans Theses and Dissertations

The mixing of polymers and nanoparticles makes it possible to give advantageous macroscopic material performance by tailoring the microstructure of composites. In this thesis, five combinations of nano inclusion and polymer matrix have been investigated.

The first type of composites is titanium dioxide/ polyaniline combination. The effects of 4 different doping-acids on the microstructure, morphology, thermal stability and thermoelectric properties were discussed, showing that the sample with HCl and sulfosalicylic dual acids gave a better thermoelectric property. The second combination is titanium dioxide/polystyrene composite. Avrami equation was used to investigate the crystallization process. The best fit of the mass derivative …