Digital Commons Network^™

Plasticity And Damage In Bimodal Grain Size Al-5083: Microstructural Finite Element, Steven Nelson

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Bimodal and nanocrystalline aluminum alloys are being investigated as stronger replacements for conventional polycrystalline aluminum alloys. Higher strengths are achieved by reducing the grain size of a metal; however, as the grain size is reduced the ductility diminishes. One solution that limits this decrease in ductility is the addition of a few microcrystalline grains into a nanocrystalline alloy, creating a bimodal microstructure that offers a better balance of strength and ductility. Two- and three-dimensional microstructural finite element (FE) simulations of monotonic and fatigue failures in Al-5083 having bimodal grain structures are conducted. To reduce the computational time and facilitate the …

Fabrication Of Multi-Material Structures Using Ultrasonic Consolidation And Laser-Engineered Net Shaping, John Olorunshola Obielodan

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This research explores the use of two additive manufacturing processes for the fabrication of multi-material structures. Ultrasonic consolidation (UC) and laser- engineered net shaping (LENS) processes were used for parallel systematic investigations of the process parameters and methodologies for the development of multi-material structures.

The UC process uses ultrasonic energy at low temperature to bond metallic foils. A wide range of metallic materials including nickel; titanium; copper; molybdenum; tantalum; MetPreg®; silver; stainless steel; and aluminum alloys 1100, 3003, and 6061 were bonded in different combinations. Material domains are inherently discrete in ultrasonically consolidated structures. The mechanical properties of some of …

Design Of An Adaptable Run-Time Reconfigurable Software-Defined Radio Processing Architecture, Joshua R. Templin

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Processing power is a key technical challenge holding back the development of a high-performance software defined radio (SDR). Traditionally, SDR has utilized digital signal processors (DSPs), but increasingly complex algorithms, higher data rates, and multi-tasking needs have exceed the processing capabilities of modern DSPs. Reconfigurable computers, such as field-programmable gate arrays (FPGAs), are popular alternatives because of their performance gains over software for streaming data applications like SDR. However, FPGAs have not yet realized the ideal SDR because architectures have not fully utilized their partial reconfiguration (PR) capabilities to bring needed flexibility. A reconfigurable processor architecture is proposed that utilizes …

Dynamic Testing, Finite Element Modeling, And Long-Term Instrumentation Of A Box Girder Post-Tensioned Bridge For The Long-Term Bridge Performance Program, Timothy Paul Thurgood

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

As part of the Long-Term Bridge Performance (LTBP) program, a flagship research program funded by the Federal Highway Administration in response to the aging bridge network, the Lambert Road Bridge near Elk Grove California was selected as the California Pilot bridge set to undergo non-destructive testing and monitoring. The purpose of the program is to obtain a database of scientific quality data concerning the health and maintenance procedures currently in use across the nation. FHWA program managers along with members of the Utah State University LTBP research team selected the bridge with the assistance of the National Bridge index and …

Integration Of Ultrasonic Consolidation And Direct-Write To Fabricate An Embedded Electrical System Within A Metallic Enclosure, Ludwing A. Hernandez

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A research project was undertaken to integrate Ultrasonic Consolitation (UC) and Direct-Write (DW) technologies into a single apparatus to fabricate embedded electrical systems within an ultrasonically consolidated metallic enclosure. Process and design guidelines were developed after performing fundamental research on the operational capabilities of the implemented system. In order to develop such guidelines, numerous tests were performed on both UC and DW. The results from those tests, as well as the design and process guidelines for the fabrication of an embedded touch switch, can be used as a base for future research and experimentation on the UC-DW apparatus. The successful …

Analysis Of Field Programmable Gate Array-Based Kalman Filter Architectures, Arvind Sudarsanam

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A Field Programmable Gate Array (FPGA)-based Polymorphic Faddeev Systolic Array (PolyFSA) architecture is proposed to accelerate an Extended Kalman Filter (EKF) algorithm. A system architecture comprising a software processor as the host processor, a hardware controller, a cache-based memory sub-system, and the proposed PolyFSA as co-processor, is presented. PolyFSA-based system architecture is implemented on a Xilinx Virtex 4 family of FPGAs. Results indicate significant speed-ups for the proposed architecture when compared against a space-based software processor. This dissertation proposes a comprehensive architecture analysis that is comprised of (i) error analysis, (ii) performance analysis, and (iii) area analysis. Results are presented …

Incorporating Spatial Information Into Gas Plume Detection In Hyperspectral Imagery, Cameron S. Grant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Detection of chemical plumes in hyperspectral data is a problem having solutions that focus on spectral information. These solutions neglect the presence of the spatial information in the scene. The spatial information is exploited in this work by assignment of prior probabilities to neighborhood configurations of signal presence or absence. These probabilities are leveraged in a total probability approach to testing for signal presence in a pixel of interest. The two new algorithms developed are named spatial information detection enhancement (SIDE) and bolt-on SIDE (B-SIDE). The results are explored in comparison to the clutter matched filter (CMF), a standard spectral …

Complexity And Power Consumption In Stochastic Iterative Decoders, Keyur M. Payak

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Stochastic iterative decoding is a novel method to decode the bits received at the end of a communication channel and to control the rate of error happening in the message bits due to noise being injected into the channel. This decoder uses stochastic computation that is based on manipulation of probabilities from a random sequence of digital bits. Hardware needed for implementing this arithmetic is very simple and can be completely implemented using simple digital complementary metal oxide gates. This helps the decoder to be technology independent, which is a major advantage over its digital and analog counterparts, which are …

Destructive Testing Of Composite Precast Concrete Deck Panels And Built-Up Steel Plate Girders, Wesley J. Cook

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The Utah Department of Transportation (UDOT) has implemented the use of precast concrete panels for bridge deck construction. A bridge utilizing these panels as a reconstruction method was decommissioned three years after the new deck installation, due to unrelated matters. Two sections of this bridge were salvaged and sent to Utah State University (USU) for destructive testing.

Each bridge section consisted of two built-up steel plate girders intact with the precast concrete deck panels. The precast panels were designed and constructed to achieve full composite action between the deck and built-up steel plate girders through the use of Nelson shear …

Destructive Testing And Finite-Element Modeling Of Full-Scale Bridge Sections Containing Precast Deck Panels, Travis R. Brackus

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Full-depth, precast panel deck systems are becoming more common in bridge installation and repair. The objective of these systems is to achieve the performance of cast-in-place systems while simultaneously saving time and money. The structural behavior of these systems has been the subject of scrutiny in recent research. The Utah Department of Transportation demolished a steel I-girder bridge containing a precast panel deck system and provided two full-scale specimens for this project. Destructive testing was performed at Utah State University on the specimens to investigate three failure modes: flexural, beam shear, and punching shear. Finite-element models were created using ANSYS …

Estimating And Verifying Household Potential To Conserve Water, Francisco J. Suero

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis identifies impacts of behaviors and technology on residential indoor water use and conservation efforts. We use pre-existing detailed end-use data collected before and after toilets, faucets, showerheads, and clothes washers were retrofitted in 96 owner-occupied, single-family households in Oakland, California; Seattle, Washington; and Tampa, Florida between 2000 and 2003.

Water volume, duration of use, and time of use were recorded and disaggregated by appliance for two weeks before and four weeks after appliances were retrofitted. For each appliance, we compare observed differences in water use before and after retrofits to water savings predicted by analytical engineering, semi-analytical engineering, …

Axisymmetric Finite Element Modeling For The Design And Analysis Of Cylindrical Adhesive Joints Based On Dimensional Stability, Paul E. Lyon

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The use and implementation of adhesive joints for space structures is necessary for incorporating fiber-reinforced composite materials. Correct modeling and design of cylindrical adhesive joints can increase the dimensional stability of space structures. The few analytical models for cylindrical adhesive joints do not fully describe the displacement or stress field of the joint.

A two-dimensional axisymmetric finite element model for the design and analysis of adhesive joints was developed. The model was developed solely for the analysis of cylindrical adhesive joints, but the energy techniques used to develop the model can be applied to other types of joints as well. …

Retrieval Of Aerosol Mass Concentration From Elastic Lidar Data, Christian C. Marchant

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Agricultural aerosol sources can contribute significantly to air pollution in many regions of the country. Characterization of the aerosol emissions of agricultural operations is required to establish a scientific basis for crafting regulations concerning agricultural aerosols. A new lidar instrument for measuring aerosol emissions is described, as well as two new algorithms for converting lidar measurements into aerosol concentration data. The average daily aerosol emission rate is estimated from a dairy using lidar.

The Aglite Lidar is a portable scanning lidar for mapping the concentration of particulate matter from agricultural and other sources. The instrument is described and performance and …

Transportation Network Resiliency: A Fuzzy Systems Approach, Nayel Urena Serulle

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Every day the dependence on transportation grows as local, regional, national, and international independence increases. Resilient transportation systems are needed to secure the highest possible level of service during disruptive events, including natural and man-made disasters. Because of limited resources, decision makers need guidance on how, when, and where to invest to improve resiliency of their networks. The research objective is to develop a method to assess and quantify resiliency, at pre-event conditions, using a fuzzy inference approach. This research expands previous work, refining key variable definitions, adjusting model interactions, and increasing transparency between metrics. This thesis presents the method …

Architecture, Modeling, And Analysis Of A Plasma Impedance Probe, Magathi Jayaram

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Variations in ionospheric plasma density can cause large amplitude and phase changes in the radio waves passing through this region. Ionospheric weather can have detrimental effects on several communication systems, including radars, navigation systems such as the Global Positioning Sytem (GPS), and high-frequency communications. As a result, creating models of the ionospheric density is of paramount interest to scientists working in the field of satellite communication.

Numerous empirical and theoretical models have been developed to study the upper atmosphere climatology and weather. Multiple measurements of plasma density over a region are of marked importance while creating these models. The lack …

Toward The Validation Of Depth-Averaged, Steady-State Simulations Of Fluvial Flows Using Three-Dimensional, Steady-State, Rans Turbulence Models, Pedro Abdiel Mateo Villanueva

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Calculations of fluvial flows are strongly influenced by geometry complexity and large overall uncertainty on every single measurable property, such as velocity and shear. Moreover, a considerable portion of the data obtained from computational simulations arose from two-dimensional, steady-state models. The present work states a different approach to perform computer-based simulations and analyze fluvial flows. For the first part, the suitability of OpenFOAM to be used as the main CFD solver to analyze fluvial flows is studied. Initially, two well documented channel configurations are computationally studied using OpenFOAM. Finally, these results are compared to the output obtained from one of …

Spatial Light Dilution As A Technique For Conversion Of Solar Energy To Algal Biomass, Daniel J. Dye

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A photobioreactor has been designed and developed to efficiently utilize solar irradiance through spatial dilution of sunlight. The concept of spatial light dilution is simple: incident sunlight is spread over a large surface area, thus reducing the photon flux density of the light. The implementation of this technique, however, is difficult. The reactor described within uses a new approach to spatial light dilution, utilizing recently-developed optical components to diffuse concentrated sunlight inside an algae culture. Preliminary productivity tests indicate a 2-3 fold increase in productivity per unit aperture (sunlight collection area) over a control reactor with direct-sunlight. Aperture productivity of …

Triso Fuel Compact Thermal Conductivity Measurement Instrument Development, Colby Jensen

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Thermal conductivity is an important thermophysical property needed for effectively predicting fuel performance. As part of the Next Generation Nuclear Plant (NGNP) program, the thermal conductivity of tri-isotropic (TRISO) fuel needs to be measured over a temperature range characteristic of its usage. The composite nature of TRISO fuel requires that measurement be performed over the entire length of the compact in a non-destructive manner. No existing measurement system is capable of performing such a measurement.

A measurement system has been designed based on the steady-state, guarded-comparative-longitudinal heat flow technique. The system as currently designed is capable of measuring cylindrical samples …

Safety Evaluation Of Work Zone Practices In Utah, Tomás Ernesto Lindheimer

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Work zones present a risk to drivers and to personnel constructing the roadway. In 2005 work zones accounted for 2.5% of fatalities nationwide, 3.5% for the state of Utah. The goal of this research is to make work zones safer by quantifying the risk that they present to drivers. The approach of this research has been to review part 6 of the Manual of Uniform Traffic Control Devices (MUTCD) and compare the differences from the 2003 and 2009 editions, conduct field studies of Utah work zones, and develop a tool for measuring risk in work zones. In the 2009 MUTCD …

Laboratory Approach To Modeling The Initiating Mechanism In The Piping Failure Of Sandy Soils, Olalekan O. Olorunsola

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

This research intends to develop a testing apparatus to measure the critical gradient in sandy soils. The designed apparatus will be used in subsequent studies to develop a relationship between critical hydraulic gradient, soil properties and the inclination of the exit face.

This study evaluates several design modification to assess the effects of the modifications, and develop a design that most closely models the field mechanism of piping initiation. The design is initiated from a conceptual design and is executed into the first version. This design is called the Alpha Version. The next version, or more precisely, the Beta Version, …

Oscillation Phenomenon Of The New York Canal At The I-84 Overpass In Boise, Idaho, Erik W. Robison

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

As part of the Idaho Transportation department's GARVEE program, the 1-84 bridge structure at the New York Canal in Boise, Idaho, was widened in 2009. During the 2009 irrigation season, oscillation patterns were noticed at the bridge structure which resulted in erosion damage to the banks of the canal. After ITD consulted with Horrocks Engineers, a contract was established with the Utah Water Research Laboratory at Utah State University to construct a Froude scale model of the structure. The purpose of the model was to determine the cause of the oscillations, and develop an effective method to eliminate them. The …

Reliability-Based Underseepage Analysis In Levees Using Monte Carlo Simulation, Lourdes Polanco

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A new method for assessing the potential for unsatisfactory levee performance due to underseepage is presented. Specifically, the method assesses the potential for the initiation of piping (the internal backward erosion of the foundation or embankment caused by seepage). Current assessment methods consist of deterministic seepage analyses and simplified reliability methods. Deterministic methods produce either a maximum hydraulic exit gradient or a Factor of Safety against piping but they do not account for high levels of uncertainty in soil properties and subsurface geometry that are inherent to many levee analyses. The most common simplified reliability approaches that are currently being …

Effects Of Static Stretching On Foot Velocity During The Instep Soccer Kick, Craig D. Workman

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

The purpose of this study was to assess the acute effects of static stretching on foot velocity at impact with a soccer ball. Eighteen Division I female soccer athletes underwent two test conditions separated by 48 hr. Each condition was randomly assigned and began by placing four retro-reflective markers on bony landmarks of the ankle (total of eight markers, four on each ankle). One condition was the no-stretch condition, in which each participant performed a self-paced jog for 5 min as a warm-up, and then sat quietly for 6 min before performing three maximal instep kicks into a net. The …

Analysis Of Square-Root Kalman Filters For Angles-Only Orbital Navigation And The Effects Of Sensor Accuracy On State Observability, Jason Knudsen Schmidt

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Angles-only navigation is simple, robust, and well proven in many applications. However, it is sometimes ill-conditioned for orbital rendezvous and proximity operations because, without a direct range measurement, the distance to approaching satellites must be estimated by firing thrusters and observing the change in the target's bearing. Nevertheless, the simplicity of angles-only navigation gives it great appeal. The viability of this technique for relative navigation is examined by building a high-fidelity simulation and evaluating the sensitivity of the system to sensor errors. The relative performances of square-root filtering methods, including Potter, Carlson, and UD factorization filters, are compared to the …

In-Pile Thermal Conductivity Measurement Methods For Nuclear Fuels, Brandon S. Fox

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Measuring nuclear fuel thermal conductivity in-pile can provide much needed data for understanding fuel performance during irradiation and yield thermophysical property data needed for simulation codes and fuel databases. The objective of this research is to develop and compare two in-pile thermal conductivity methods in a laboratory setting using surrogate fuel materials.

A steady-state radial heat flow method was investigated to understand its viability as an in-pile steady-state thermal conductivity technique. By using Joule heating to simulate volumetric heat generation within a surrogate fuel rod, thermal conductivity was measured with two thermocouples at different radial positions within the rod. Examinations …

Experiment And Simulation On The Dynamics Of A Slug Of Liquid Oxygen Displaced By A Pulsed Magnetic Field, Jeffrey C. Boulware

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A magnetic fluid system could potentially replace mechanically moving parts in a satellite as a means of increasing system reliability and mission lifetime, but rather than a standard ferrofluid with magnetic particles, liquid oxygen (LOX) may be a more adequate working fluid. As a pure paramagnetic cryogen, LOX is already heavily used in space, but still requires basic research before being integrated into system development. The objectives of the research conducted were to verify LOX as a magnetic working fluid through experiment and establish a theoretical model to describe its behavior. This dissertation presents the theoretical, experimental, and numerical results …

Architecture, Inertial Navigation, And Payload Designs For Low-Cost Unmanned Aerial Vehicle-Based Personal Remote Sensing, Calvin Coopmans

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis presents work done towards a Personal Remote Sensing (PRS) system: small Unmanned Aerial Vehicles (UAVs) with electronic, control, and sensing subsystems. Based on papers presented to conferences (AutoTestCon2008 and MESA2009), as well as other work on PRS, multiple levels of engineering are detailed: complex multi-UAV data flow; attitude estimation filters; real-time microprocessor functionality; and small, mobile power systems. Wherever possible, Open-Source tools and designs have been used, modified, or studied, providing excellent cost to performance ratios in most cases. First, the overall PRS UAV architecture, AggieAir, is presented with a motivating examples (GhostEye and EagleEye camera payloads). Then, …

An Exploration Of Formal Methods And Tools Applied To A Small Satellite Software System, Russell J. Grover

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Formal system modeling has been a topic of interest in the research community for many years. Modeling a system helps engineers understand it better and enables them to check different aspects of it to ensure that there is no undesired or unexpected behavior and that it does what it was designed to do. This thesis takes two existing tools that were created to aid in the designing of spacecraft systems and creates a layer to connect them together and allow them to be used jointly. The first tool is a library of formal descriptions used to specify spacecraft behavior in …

Micro Electro Mechanical Systems Integrated Frequency Reconfigurable Antennas For Public Safety Applications, Hema Swaroop Mopidevi

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

This thesis work builds on the concept of reconfiguring the antenna properties (frequency, polarization, radiation pattern) using Radio Frequency (RF) Micro Electro Mechanical Systems (MEMS). This is a part of the overall research performed at the RF Micro/Nano Electro Mechanical Systems (μN∈MS) Laboratory at Utah State University, which includes design, microfabrication, test, and characterization of μN∈MS integrated cognitive wireless communication systems (Appendix A).

In the first step, a compact and broadband Planar Inverted F Antenna (PIFA) is designed with a goal to accommodate reconfigurability at a later stage. Then, a Frequency Reconfigurable Antenna …

Fatigue Life Analysis Of T-38 Aileron Lever Using A Continuum Damage Approach, James D. Gyllenskog

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

In a recent investigation conducted by the United States Air Force, the mechanical failure of the aileron lever, manufactured from 2014-T6 aluminum, caused the fatal mishap of a T-38 trainer aircraft. In general the locations of cracks are unknown and must be determined by simulation. In this study we propose to use a continuum damage modeling approach to determine the degradation and damage in a material as the number of cycles of loading increases. This approach successfully predicts the location of crack initiation, propagation path, and propagation rate. A stress-based model in conjunction with the successive initiation technique is utilized. …