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Origami-Based Design Of Fold States And Stability, Alex Avila
Origami-Based Design Of Fold States And Stability, Alex Avila
Theses and Dissertations
Origami is a potentially elegant and powerful source of inspiration for many engineering designs. The viable shapes (fold states) of a single device allow it to perform multiple, seemingly contradictory, functions. The fold state is a large factor in the device's performance, but there are challenges in selecting and maintaining those fold states. In this thesis we analyze existing concepts for overcoming these challenges. Those concepts are compared with those that occur in origami-based devices. From this analysis fundamental gaps were identified, specifically, shortcoming in the terminology used to refer to (1) non-flat origami states and (2) sets of facets …
Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau
Estimation Of Knee Kinematics Using Non-Monotonic Nanocomposite High-Deflection Strain Gauges, Adin Douglas Martineau
Theses and Dissertations
Human knee kinematics, especially during gait, are an important analysis tool. The current "gold standard" for kinematics measurement is a multi-camera, marker-based motion capture system with 3D position tracking. These systems are accurate but expensive and their use is limited to a confined laboratory environment. High deflection strain gauges (HDSG) are a novel class of sensors that have the potential to measure kinematics and can be inexpensive, low profile, and are not limited to measurements within a calibrated volume. However, many HDSG sensors can have a non-linear and non-monotonic response. This thesis explores using a nanocomposite HDSG sensor system for …
The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden
The Design, Construction, And Thermal Diffusivity Measurements Of The Fluorescent Scanning Thermal Microscope (Fstm), Samuel Hunter Hayden
Theses and Dissertations
Over the life of nuclear fuel, inhomogeneous structures develop, negatively impacting thermal properties. New fuels are under development, but require more accurate knowledge of how the properties change to model performance and determine safe operational conditions. Measurement systems capable of small–scale, pointwise thermal property measurements and low cost are necessary to measure these properties and integrate into hot cells where electronics are likely to fail during fuel investigation. This project develops a cheaper, smaller, and easily replaceable Fluorescent Scanning Thermal Microscope (FSTM) using the blue laser and focusing circuitry from an Xbox HD-DVD player. The FSTM also incorporates novel fluorescent …
Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick
Examining The Mechanics Responsible For Strain Delocalization In Metallic Glass Matrix Composites, Casey Owen Messick
Theses and Dissertations
Metallic glass matrix composites (MGMCs) have been developed to improve upon the ductility of monolithic metallic glass. These composites utilize a secondary crystalline phase that is grown into an amorphous matrix as isolated dendritic trees. This work seeks to understand the mechanisms underlying strain delocalization in MGMCs in order to better direct efforts for continual progress in this class of material. A mesoscale modelling technique based on shear transformation zone (STZ) dynamics is used to do so. STZ dynamics is a coarse grained technique that can provide insight into the microscopic processes that control macroscopic behavior, but which can be …
5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj
5d Grain Boundary Characterization From Ebsd Microscopy, Akash Savio Amalaraj
Theses and Dissertations
Knowledge of the full 5-degree Grain Boundary Character Distribution (GBCD) is vital to understanding properties, such as gas diffusivity, that are dominated by grain boundary character. Surface characterization techniques, such as Electron Backscattered diffraction (EBSD), can provide only 4 of the 5 GB characteristics (the rotation between the neighboring grains, and the trace of the GB on the surface). The inclination of the GB in the direction normal to the surface is not known. A previous study indicated that the GB inclination could be recovered by correlating the Electron Backscattered patterns (EBSPs) of sample points near the GB with EBSPs …
Using Non-Destructive Testing To Predict Bending Modulus Of Carbon Infiltrated-Carbon Nanotubes, Fred Stile Fagergren
Using Non-Destructive Testing To Predict Bending Modulus Of Carbon Infiltrated-Carbon Nanotubes, Fred Stile Fagergren
Theses and Dissertations
Fabrication of carbon infiltrated carbon nanotubes (CI-CNT) can result in large mechanical property variation, and methods to characterize properties usually involve destructive testing. Finding a non-destructive way to test for stiffness of this material reduces the number of parts that have to be made. It also simplifies testing of complex parts. The stiffness of CI-CNT beams is related to the type of carbon material infiltrated between the carbon nanotubes (CNTs), how it interacts with the CNTs, and how much of it there is. The amount of material can be estimated using the density of the beam, and both the type …
Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth
Wall Shear Stress In Simplified And Scanned Avian Respiratory Airways, Michael Sterling Farnsworth
Theses and Dissertations
Birds uniquely produce sound through a vocal organ known as a syrinx. The presence of wall shear stress acting on the airway cells of any organism will affect how airway cells develop and multiply. Unique features of avian airway geometry and breathing pattern might have contributed to the development of the syrinx. This thesis examines wall shear stress in the trachea and first bronchi of avian geometries using computational fluid dynamics. The computational fluid dynamic simulations underwent grid- and time-independence studies and were validated using particle image velocimetry. Parameters such as bird size, bronchial branching angle, and breathing waveform were …
Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor
Internal Deformation Measurements And Optimization Of Synthetic Vocal Fold Models, Cassandra Jeanne Taylor
Theses and Dissertations
Developing lifelike vocal fold models is challenging due to various associatedbiomechanical complexities. Nevertheless, the development and analysis of improved vocal foldmodels is worthwhile since they are valuable tools for gaining insight into human vocal foldvibratory, aerodynamic, and acoustic response characteristics. This thesis seeks to contribute tothe development of computational and physical vocal fold modeling in two ways. First is byintroducing a method of obtaining internal deformation fields within vibrating synthetic vocal foldmodels; second is by presenting an optimization algorithm coupled with a computational vocalfold model to optimize geometry and stiffness of a synthetic vocal fold model to achieve morerealistic vibration …
Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson
Investigation Of An Isotruss Structure As A Compliant Member Used In Bending And Torsion, Jens Garret Jacobson
Theses and Dissertations
An investigation of IsoTruss structures in bending and torsion was conducted. A model was developed in ANSYS APDL where bay length and longitudinal member to helical member cross-sectional area ratio could be varied while holding the diameter constant. The model was validated using previously reported values from analytical models and empirical data. The model was used to make predictions of a specific geometry that was manufactured, tested and compared against the model. 12 specimens were built and tested. In flexure, empirical data had a percent error with respect to the model ranging from 10.9 to 65.4% with one outlier at …
Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore
Distributed Electric Propulsion Conceptual Design Applied To Traditional Aircraft Take Off Distance Through Multidisciplinary Design, Kevin Ray Moore
Theses and Dissertations
While vertical takeoff and landing aircraft show promise for urban air transport, distributed electric propulsion on existing aircraft may offer an immediately implementable alternative. Dis- tributed electric propulsion has the potential of increasing the aircraft thrust-to-weight ratio and lift coefficient high enough to enable takeoff distances of less than 100 meters. While fuel based propulsion technologies generally increase in specific power with increasing size, electric propul- sion typically can be decreased in size without a decrease in specific power. The smaller but highly power-dense propulsion units enable alternative designs including many small units, optionally powered units, and vectored thrust from …
Coordinated, Multi-Arm Manipulation With Soft Robots, Dustan Paul Kraus
Coordinated, Multi-Arm Manipulation With Soft Robots, Dustan Paul Kraus
Theses and Dissertations
Soft lightweight robots provide an inherently safe solution to using robots in unmodeled environments by maintaining safety without increasing cost through expensive sensors. Unfortunately, many practical problems still need to be addressed before soft robots can become useful in real world tasks. Unlike traditional robots, soft robot geometry is not constant but can change with deflation and reinflation. Small errors in a robot's kinematic model can result in large errors in pose estimation of the end effector. This error, coupled with the inherent compliance of soft robots and the difficulty of soft robot joint angle sensing, makes it very challenging …
Thermal Transport At Superhydrophobic Surfaces In Impinging Liquid Jets, Natural Convection, And Pool Boiling, Matthew Clark Searle
Thermal Transport At Superhydrophobic Surfaces In Impinging Liquid Jets, Natural Convection, And Pool Boiling, Matthew Clark Searle
Theses and Dissertations
This dissertation focuses on the effects of superhydrophobic (SHPo) surfaces on thermal transport. The work is divided into two main categories: thermal transport without phase change and thermal transport with phase change. Thermal transport without phase change is the topic of four stand-alone chapters. Three address jet impingement at SHPo surfaces and the fourth considers natural convection at a vertical, SHPo wall. Thermal transport with phase change is the topic of a single stand-alone chapter exploring pool boiling at SHPo surfaces. Two chapters examining jet impingement present analytical models for thermal transport; one considered an isothermal wall and the other …
Modeling Vocal Fold Intravascular Flow With Synthetic Replicas, Aaron David Terry
Modeling Vocal Fold Intravascular Flow With Synthetic Replicas, Aaron David Terry
Theses and Dissertations
Communication by voice is foundational in our society and many rely on their voices for their occupations. Voice disorders affect a significant number of individuals each year, and diagnosis and treatment improvements are therefore sought via advancements in voice research. Contained in this thesis is a description of work intended to contribute to vocal fold research by using synthetic, self-oscillating vocal fold replicas to study the impact of replica vibration on perfusion fluid flow through the replica. Methods for manufacturing vocal fold replicas containing imbedded channels allowing for fluid perfusion are discussed. Experimental procedures developed for delivering perfusion fluid to …
Methods And Metrics To Measure And Predict The Social Impact Of Engineered Products, Phillip Douglas Stevenson
Methods And Metrics To Measure And Predict The Social Impact Of Engineered Products, Phillip Douglas Stevenson
Theses and Dissertations
More than ever before, engineers are creating products for developing countries. One of the purposes of these products is to improve the consumer's quality of life. Currently, there is no established method of measuring the social impact of these types of products. As a result, engineers have used their own metrics to assess their product's impact, if at all. Some of the common metrics used include products sold and revenue, which measure the financial success of a product without recognizing the social successes or failures it might have. In this thesis I introduce a potential metric, the Product Impact Metric …
Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Taylor Ingersoll
Efficient Incorporation Of Fatigue Damage Constraints In Wind Turbine Blade Optimization, Bryce Taylor Ingersoll
Theses and Dissertations
Improving the wind turbine blade design has a significant effect on the efficiency of the wind turbine. This is a challenging multi-disciplinary optimization problem. During the blade design process, the aerodynamic shapes, sizing of the structural members, and material composition must all be determined and optimized. Some previous blade design methods incorporate the wind turbine's static response with an added safety factor to account for neglected dynamic effects. Others incorporate the dynamic response, but in general is limited to a few design cases. By not fully incorporating the dynamic response of the wind turbine, the final turbine blade design is …
Tactile Sensing And Position Estimation Methods For Increased Proprioception Of Soft-Robotic Platforms, Nathan Mcclain Day
Tactile Sensing And Position Estimation Methods For Increased Proprioception Of Soft-Robotic Platforms, Nathan Mcclain Day
Theses and Dissertations
Soft robots have the potential to transform the way robots interact with their environment. This is due to their low inertia and inherent ability to more safely interact with the world without damaging themselves or the people around them. However, existing sensing for soft robots has at least partially limited their ability to control interactions with their environment. Tactile sensors could enable soft robots to sense interaction, but most tactile sensors are made from rigid substrates and are not well suited to applications for soft robots that can deform. In addition, the benefit of being able to cheaply manufacture soft …
Methods For Creating Rigid Foldability In Origami-Inspired Deployable Mechanisms, Alden Daniel Yellowhorse
Methods For Creating Rigid Foldability In Origami-Inspired Deployable Mechanisms, Alden Daniel Yellowhorse
Theses and Dissertations
Because origami has proved to be a tremendously rich source of inspiration in engineering, interest in solving some of the challenges that affect origami-inspired design has been significant. One such challenge involves ensuring that origami-inspired mechanisms are rigid-foldable or capable of moving without requiring links to bend or distort. Because rigid-foldability is essential in mechanisms that are constructed using rigid materials, access to methods of engineering this characteristic are highly desirable. This research addresses this need by developing methods for the design of origami-inspired mechanisms that are rigid-foldable. Methods for modifying crease patterns to achieve this are described and compared. …
Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron
Augmented Design Capabilities For Origami Tessellations, Janette Darlene Herron
Theses and Dissertations
Applying engineering principles to tessellation origami-based designs enables the control of certain design properties, such as flexibility, bending stiffness, mechanical advantage, shape conformance, and deployment motion. The ability to control these and other properties will enable augmented design capabilities in environments which currently limit the design to specific materials, including space, medicine, harsh environments, and scaled environments (such as MEMS applications). Other applications will be able to achieve more complex motions or better satisfy design and performance requirements.This research demonstrates augmented design capabilities of origami tessellations in engineering design in rigid-foldable and non-rigid-foldable applications. First, a method to determine Poisson's …
Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson
Art To Engineering: Curved Folding And Developable Surfaces In Mechanism And Deployable Structure Design, Todd G. Nelson
Theses and Dissertations
This work investigates how curved-crease origami and the developable surfaces which compose it can be transitioned to engineering design. Methods for creating flexible, tailorable-property surfaces that function as thick panels in place of paper are presented. Concepts from curved-crease origami and developable surfaces that can describe and extend engineering applications are discussed and demonstrated. These concepts are particularly beneficial to applications where curved surfaces are integral to the function, deployability is desired, and planar manufacturing could be beneficial.The first part of this work uses arrays of compliant elements to create flexible-tailorable property surfaces. The key feature to these arrays is …
Friction Bit Joining Of Similar Alloy Sheets Of High-Strength Aluminum Alloy 7085, Matthew R. Okazaki
Friction Bit Joining Of Similar Alloy Sheets Of High-Strength Aluminum Alloy 7085, Matthew R. Okazaki
Theses and Dissertations
Friction Bit Joining (FBJ) is a new technology used primarily in joining dissimilar metals. Its primary use has been focused in the automotive industry to provide an alternative joining process to welding. As automotive manufacturing has continually pushed toward using dissimilar materials, new joining processes have been needed to replace traditional welding practices that do not perform well when materials are not weld compatible. FBJ meets these needs perfectly as it provides strength as well as the ability to join materials of almost any kind.The purpose of this research was to explore different applications of the FBJ process. Traditionally FBJ …
Force And Motion Based Methods For Planar Human-Robot Co-Manipulation Of Extended Objects, Erich Allen Mielke
Force And Motion Based Methods For Planar Human-Robot Co-Manipulation Of Extended Objects, Erich Allen Mielke
Theses and Dissertations
As robots become more common operating in close proximity to people, new opportunities arise for physical human-robot interaction, such as co-manipulation of extended objects. Co-manipulation involves physical interaction between two partners where an object held by both is manipulated in tandem. There is a dearth of viable high degree-of-freedom co-manipulation controllers, especially for extended objects, as well as a lack of information about how human-human teams perform in high degree-of-freedom tasks. One method for creating co-manipulation controllers is to pattern them off of human data. This thesis uses this technique by exploring a previously completed experimental study. The study involved …
Development, Classification And Biomedical Applications Of Nano Composite Piezoresponsive Foam, Aaron Jake Merrell
Development, Classification And Biomedical Applications Of Nano Composite Piezoresponsive Foam, Aaron Jake Merrell
Theses and Dissertations
This dissertation focuses on the development of and applications for Nano-Composite Piezoresponsive Foam (NCPF). This self-sensing foam sensor technology was discovered through research in a sister technology, High Deflection Strain Gauges (HDSG), and was subsequently developed with some of the same base materials. Both technologies use nano and micro conductive additives to provide electrically responsive properties to materials which otherwise are insulative. NCPF sensors differ from HDSGs in that they provide a dual electrical response to dynamic and static loading, which is measured through an internally generated charge, or a change in resistance. This dissertation focuses on the development of …
Heterogeneous Templated Grain Growth, Dallin James Frandsen
Heterogeneous Templated Grain Growth, Dallin James Frandsen
Theses and Dissertations
Heterogeneous Templated Grain Growth (HTGG) is a developing method to fabricate designedcrystallographic textures of polycrystalline materials. Designed crystallographic texturesare important for enhancing desired material properties for specific applications. Four steps toHTGG have been identified: fabricating single crystal seeds, aligning seeds embedded into a powdermatrix, compacting seeds in the powder matrix, and promoting templating through sintering.Experimental research was performed on processing parameters, powder particle size and compaction,to indicate template coarsening trends during sintering. The results demonstrated thatlarger powder particles were influenced faster by the seeds crystallographic orientations comparedto smaller particles. The local effects of porosity on the seed and powder interface …
A Comparative Analysis Of Computer-Aided Collaborative Design Tools And Methods, Keenan Louis Eves
A Comparative Analysis Of Computer-Aided Collaborative Design Tools And Methods, Keenan Louis Eves
Theses and Dissertations
Collaboration has always been critical to the success of new product development teams, and the advent of geographically dispersed teams has significantly altered the way that team members interact. Multi-user computer-aided design (MUCAD) and crowdsourcing are two results of efforts to enable collaboration between geographically dispersed individuals. In this research, a study was done to investigate the differences in performance between MUCAD and single-user CAD teams, in which teams competed to create the best model of a hand drill. This was done across a three-day period to recreate the scenario found in industry. It was found that MUCAD increases awareness …
Using Collapsible Systems To Mitigate Buckling In Thin Flexible Instruments In Robotic Surgery, Brandon Scott Sargent
Using Collapsible Systems To Mitigate Buckling In Thin Flexible Instruments In Robotic Surgery, Brandon Scott Sargent
Theses and Dissertations
Robotic surgery procedures may include long, thin flexible instruments that are inserted by the robot into the patient. As the robot inserts these devices, due to their geometry, they are prone to buckling failure. To mitigate buckling failure, a support system is needed on the robot. This system supports the device but also adapts to the varying ex vivo length of the device as it is inserted. This work presents four collapsible support systems designed to mitigate buckling failure of long, thin instruments while accounting for changing length. The Ori-Guide is an origami-inspired system that has enabled a part reduction …
Stress Modulated Grain Boundary Mobility, Derek Michael Lontine
Stress Modulated Grain Boundary Mobility, Derek Michael Lontine
Theses and Dissertations
This thesis consists of a thermodynamically based kinetic model that more accurately predicts grain boundary mobility (GBM) over a large range of thermodynamic states including changes in temperature, pressure and shear stress. The form of the model was validated against calculated GBM values for Al bicrystals via molecular dynamics (MD) simulations. A total of 98,786 simulations were performed (164 different GBs, each with a minimum of 250 different thermodynamic states, and 2 different driving forces). Methodology for the computation of the GBM via MD simulations is provided. The model parameters are directly linked to extensive thermodynamic quantities and suggest potential …
A Definition And Demonstration Of Developable Mechanisms, Trent Karl Zimmerman
A Definition And Demonstration Of Developable Mechanisms, Trent Karl Zimmerman
Theses and Dissertations
There is an increasing need for compact mechanical systems that can accomplish sophisticated tasks. Technologies like ortho-planar and lamina emergent mechanisms (LEMs) have been developed to satisfy needs like these by stowing in planar sheets from which they emerge to perform their function. They can be compact, lightweight, monolithic, scalable, and can withstand harsh environments. They are limited, however, by their base element---planar surfaces. Applications requiring these advantages often include curved surfaces, like aircraft wings, needles, and automotive bodies. In this research, developable mechanisms are presented as a solution to satisfy the need for mechanisms that can conform to or …
Simulation Of The Inertia Friction Welding Process Using A Subscale Specimen And A Friction Stir Welder, Ty Samual Dansie
Simulation Of The Inertia Friction Welding Process Using A Subscale Specimen And A Friction Stir Welder, Ty Samual Dansie
Theses and Dissertations
This study develops a method to simulate a full-scale inertia friction weld with a sub-scale specimen and modifies a direct drive friction stir welder to perform the welding process. A torque meter is fabricated for the FSW machine to measure weld torque. Machine controls are modified to enable a force control during the IFW process. An equation is created to measure weld upset due to deflection of the FSW machine. Data obtained from a full-scale inertia friction weld are altered to account for the geometrical differences between the sub-scale and full-scale specimens. The IFW are simulated with the sub-scale specimen …
Quantifying Grain Boundary Atomic Structures Using The Smooth Overlap Of Atomic Positions, Jonathan Lake Priedeman
Quantifying Grain Boundary Atomic Structures Using The Smooth Overlap Of Atomic Positions, Jonathan Lake Priedeman
Theses and Dissertations
In this work, the relationship between grain boundary crystallography and grain boundary atomic structure is examined, using [1 0 0] - symmetric tilt grain boundaries in nickel. The structural unit model is used as a benchmark to evaluate the atomic structure description capacities of an emerging structural descriptor, the local environment representation, which itself is a refinement of the also-emergent Smooth Overlap of Atomic Positions (SOAP) descriptor. We show that the local environment representation encodes both the information of the structural unit model and additional information, such as distortion in the structural units and the arrangement of the structural units …
Effect Of Gyroscope Parameters On Gyroscopic Tremor Suppression In A Single Degree Of Freedom, Brendon Connor Allen
Effect Of Gyroscope Parameters On Gyroscopic Tremor Suppression In A Single Degree Of Freedom, Brendon Connor Allen
Theses and Dissertations
Although tremor is one of the most common movement disorders, there are few effective tremor-suppressing options available to patients. One potential tremor-suppression device involves a wearable gyrostabilizer similar to those used to stabilize cameras. However, we do not currently know how to design a gyrostabilizer to suppress tremor in an optimal manner. To address this gap, we present a systematic investigation of how gyrostabilizer parameters affect tremor suppression in a single degree of freedom (DOF). A simple model of the hand with a single DOF at the wrist and a gyroscope mounted on the back of the hand was used …