Engineering Commons^™

Constant Voltage Hot-Wire Anemometry For The Boundary Layer Data System, Hon Yee Li

Master's Theses

To continue the development of the Boundary Layer Data System (BLDS), a constant voltage hot-wire anemometer (CVA) is implemented into the BLDS for flight-testing. The hot-wire anemometer was chosen as an alternative to the traditional pressure probe because of the ability to measure both average velocity and fluctuating velocity within the boundary layer. Previous work done on the benchtop has led to the design of miniaturization, flight-capable hardware for the BLDS. The next step in the development of the BLDS – CVA calls for quantifying the accuracy of the boundary layer measurements measured by the CVA system. To do this, …

Active Learning Using Model-Eliciting Activities And Inquiry-Based Learning Activities In Dynamics, Jeffrey Phillip Georgette

Master's Theses

This thesis focuses on a year-long project of implementing active learning in undergraduate dynamics courses at Cal Poly San Luis Obispo from 2012-2013. The purpose is to increase conceptual understanding of critical dynamics concepts and to repair misconceptions of the students. Conceptual understanding in Dynamics is vital to understanding the big picture, building upon previous knowledge, and better understanding the behavior of engineering systems. Through various hands-on activities, students make predictions, test their conceptions, and solve real world problems. These active learning methods allow students to improve their learning of Dynamics concepts. Education research on active learning is present in …

Large-Displacement Lightweight Armor, Eric C. Clough

Master's Theses

Randomly entangled fibers forming loosely bound nonwoven structures are evaluated for use in lightweight armor applications. These materials sacrifice volumetric efficiency in order to realize a reduction in mass versus traditional armor materials, while maintaining equivalent ballistic performance. The primary material characterized, polyester fiberfill, is shown to have improved ballistic performance over control samples of monolithic polyester as well as 1095 steel sheets. The response of fiberfill is investigated at a variety of strain rates, from quasistatic to ballistic, under compression, tension, and shear deformation to elucidate mechanisms at work during ballistic defeat. Fiberfill’s primary mechanisms during loading are fiber …

Development And Validation Of A Human Hip Joint Finite Element Model For Tissue Stress And Strain Predictions During Gait, Jeffrey D. Pyle

Master's Theses

Articular cartilage degeneration, called osteoarthritis, in the hip joint is a serious condition that affects millions of individuals yearly, with limited clinical solutions available to prevent or slow progression of damage. Additionally, the effects of high-risk factors (e.g. obesity, soft and hard tissue injuries, abnormal joint alignment, amputations) on the progression of osteoarthritis are not fully understood. Therefore, the objective of this thesis is to generate a finite element model for predicting osteochondral tissue stress and strain in the human hip joint during gait, with a future goal of using this model in clinically relevant studies aimed at prevention, treatment, …

Cae Methods On Vibration-Based Health Monitoring Of Power Transmission Systems, Brian Fang

Master's Theses

This thesis focuses on different methods to analyze power transmission systems with computer software to aid in detection of faulty or damaged systems. It is split into three sections. The first section involves utilizing finite element software to analyze gear stiffness and stresses. A quasi-static and dynamic analysis are done on two sets of fixed axis spur gears and a planetary gear system using ABAQUS to analyze the stress, strain and gear mesh stiffness variation. In the second section, the vibrational patterns produced by a simple bevel gear system are investigated by an experiment and by dynamic modeling in ADAMS. …

Investigation Of Compressed Air Energy Storage Efficiency, James W. Keeney

Master's Theses

This study investigates Compressed Air Energy Storage (CAES) application in the

electrical power and transportation industries. Information concerning current CAES projects is

presented. A thorough thermodynamic analysis of the CAES process is completed; including

theoretical efficiency determination for several variants of the compression and expansion

processes. Industry claimed efficiencies ranging from 26% to 82% are presented and explained.

Isothermal and Isentropic efficiency baselines are developed. Energy density of compressed air

on both a mass and volume basis is compared to other energy storage methods. Best expected

efficiency of a hypothetical CAES system is determined to be 34% using currently achievable …

Development And Validation Of A Human Knee Joint Finite Element Model For Tissue Stress And Strain Predictions During Exercise, Spencer D. Wangerin

Master's Theses

Osteoarthritis (OA) is a degenerative condition of cartilage and is the leading cost of disability in the United States. Motion analysis experiments in combination with knee-joint finite element (FE) analysis may be used to identify exercises that maintain knee-joint osteochondral (OC) loading at safe levels for patients at high-risk for knee OA, individuals with modest OC defects, or patients rehabilitating after surgical interventions. Therefore, a detailed total knee-joint FE model was developed by modifying open-source knee-joint geometries in order to predict OC tissue stress and strain during the stance phase of gait. The model was partially validated for predicting the …

Mode I Fracture Toughness Of Eight-Harness-Satin Carbon Cloth Weaves For Co-Cured And Post-Bonded Laminates, Josh E. Smith

Master's Theses

Mode I interlaminar fracture of 3k 8-Harness-Satin Carbon cloth, with identical fill and weft yarns, pre-impregnated with Newport 307 resin was investigated through the DCB test (ASTM D5528). Crack propagations along both the fill and weft yarns were considered for both post-bonded (co-bonded) and co-cured laminates. A patent-pending delamination insertion method was compared to the standard Teflon film option to assess its applicability to mode I fracture testing. The Modified Beam Theory, Compliance Calibration method, and Modified Compliance Calibration method were used for comparative purposes for these investigations and to evaluate the validity of the proposed Equivalent Stiffness (EQS) method. …

Robotic Fingerspelling Hand For The Deaf-Blind, Jerry Vin

Master's Theses

Because communication has always been difficult for people who are deaf-blind, The Smith-Kettlewell Eye Research Institute (SKERI), in conjunction with the California Polytechnic State University Mechanical Engineering department, has commissioned the design, construction, testing, and programming of a robotic hand capable of performing basic fingerspelling to help bridge the communication gap. The hand parts were modeled using SolidWorks and fabricated using an Objet rapid prototyper. Its fingers are actuated by 11 Maxon motors, and its wrist is actuated by 2 Hitec servo motors. The motors are controlled by Texas Instruments L293D motor driver chips, ATtiny2313 slave microcontroller chips programmed to …

Design And Implementation Of Eight-Legged Robotic Transporter, Jeremy David Depangher

Master's Theses

This thesis contains the design, manufacturing, and testing of a functional eight-legged robotic transporter based on the concept design laid out in U.S. Patent 7,246,671. The device is intended to achieve three different sequences of motion: regular driving, obstacle climbing, and stair climbing. The prototype was carried through concept design, analysis, selection of materials and components, manufacturing, software development, and final assembly and testing. The device can be assembled under multiple configurations, which harbor certain advantages and disadvantages. The results of the testing encourage the continuation of a second iteration of this concept.

Qualitative Methods Used To Develop And Characterize The Circulation Control System On Cal Poly's Amelia, Eric N. Paciano

Master's Theses

The circulation control system onboard Cal Poly's Advanced Model for Extreme Lift and Improved Aeroacoustics was a critical component of a highly complex wind tunnel model produced in order to fulfill the requirements of a NASA Research Announcement awarded to David Marshall of the Aerospace Engineering Department. The model was based on a next generation, 150 passenger, regional, cruise efficient, short take-off and landing concept aircraft that achieved high lift through circulation control wings and over-the-wing mounted engines. The wind tunnel model was 10-ft in span, used turbine propulsion simulators, and had a functioning circulation control system driven from tunnel …

Material Characterization Of Nitinol Wires For The Design Of Actuation Systems, Sean P. Kennedy

Master's Theses

A series of tests were performed on nickel-titanium alloy wire, also known as nitinol, to determine the plausibility of designing an actuator using this wire as the method of actuation. These tests have been designed to fully characterize how the wire behaves under steady state and transient conditions allowing for a specific wire selection to be made given known actuator specifications which will result in an efficient design. The wire transient data can be used to design a controller which reduces the actuation time. The research done for the overall project covers a wide scope including wire hysteresis, nitinol transition …

Microphone-Based Pressure Diagnostics For Boundary Layer Transition, Spencer Everett Lillywhite

Master's Theses

An experimental investigation of the use low-cost microphones for unsteady total pressure measurement to detect transition from laminar to turbulent boundary layer flow has been conducted. Two small electret condenser microphones, the Knowles FG-23629 and the FG-23742, were used to measure the pressure fluctuations and considered for possible integration with an autonomous boundary layer measurement system. Procedures to determine the microphones’ maximum sound pressure levels and frequency response using an acoustic source provided by a speaker and a reference microphone. These studies showed that both microphones possess a very flat frequency response and that the max SPL of the FG-23629 …

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 …

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 …

Transient Small Wind Turbine Tower Structural Analysis With Coupled Rotor Dynamic Interaction, George R. Katsanis

Master's Theses

Structural dynamics is at the center of wind turbine tower design - excessive vibrations can be caused by a wide range of environmental and mechanical sources and can lead to reduced component life due to fatigue, noise, and impaired public perception of system integrity. Furthermore, periodic turbulent wind conditions can cause system resonance resulting in significantly increased structural loads. Structural vibration issues may become exacerbated in small wind applications where the analytical and experimental resources for system verification and optimization are scarce. This study combines several structural analysis techniques and packages them into a novel and integrated form that can …

Analysis And Mitigation Of The Cubesat Dynamic Environment, Steve M. Furger

Master's Theses

A vibration model was developed for CubeSats inside the Poly-Picosatellite Orbital Deployer (P-POD). CubeSats are fixed in the Z axis of deployers, and therefore resonate with deployer peaks. CubeSats generally start fixed in the X and Y axes, and then settle into an isolated position. CubeSats do not resonate with deployers after settling into an isolated position. Experimental data shows that the P-POD amplifies vibration loads when CubeSats are fixed in the deployer, and vibration loads are reduced when the CubeSats settle into an isolated position. A concept for a future deployer was proposed that isolates CubeSats from the deployer …

Novel Approach To Junctional Bleeding: Tourniquet Device Proposal For Battlefield Hemorrhage Control, Kyle W. Cabaniss

Master's Theses

This study investigated possible solutions to the current wartime problem of junctional hemorrhaging, or massive traumatic hemorrhaging in non-tourinquetable areas such as the neck, groin, or armpit. Junctional hemorrhaging has been identified as a major contributor to potentially survivable deaths seen on the battlefield today and therefore is a priority for the U.S. armed and coalition forces (Kragh et al., 2011a; Bozeman, 2011). Common tourniquets today are standard issue and carried by soldiers in the military, but are limited to distal extremity trauma. As the battlefield has changes however, trauma has transformed from commonly seen gunshot wounds to more extreme …

Material Characterization And The Effects Of Moisture And Drying On Injection Molded Torlon 5030, Michael R. Di Re

Master's Theses

The effects of water absorption and drying were studied on injection molded Torlon 5030, a high performance thermoplastic fabricated by Solvay Specialty Polymers. Torlon 5030 contains 30% by weight glass fibers in a polyamide-imide base resin. The objective behind this work was to test and better define relevant properties for industrial applications using this material. While the material design guide offers information on many mechanical properties including tensile, fatigue, and creep data; there is little to no publicly published data on the effects of water absorption and any subsequent drying of Torlon 5030. Blistering was also studied. With exposure to …

The Effect Of Sensor Mass, Sensor Location, And Delamination Location Of Different Composite Structures Under Dynamic Loading, Albert Darien Liu

Master's Theses

This study investigated the effect of sensor mass, sensor location, and delamination location of different composite structures under dynamic loading. The study pertains to research of the use of accelerometers and dynamic response as a cost-effective and reliable method of structural health monitoring in composite structures. The composite structures in this research included carbon fiber plates, carbon fiber-foam sandwich panels, and carbon-fiber honeycomb sandwich panels. The composite structures were manufactured with the use of a Tetrahedron MTP-8 heat press. All work was conducted in the Cal Poly Aerospace Structures/Composites Laboratory. Initial delaminations were placed at several locations along the specimen, …