Mechanical Engineering Commons^™

Impact Of Operational Conditions On The Transient Thermal Behavior Of Lithium-Ion Batteries, Jairo Sebastian Casa

College of Graduate Studies: Theses & Dissertations

Considering the high increase of lithium-ion batteries (LIBs) through the years, it is important to analyze the impact of the operational conditions, such as charging and discharging on the transient thermal behavior of LIBs for thermal management of Li-Ion batteries. A pseudo two-dimensional mathematical model based on the finite volume method (Doyle-Fuller Newman) available in an open-source environment such as Python, was utilized for the electrochemical evaluation of the Li-Ion battery. For simplicity, a lumped thermal model was integrated with the electrochemistry model to evaluate the transient behavior of Li-Ion cells under varying conditions. Both the electrochemistry and lumped thermal …

Stability Analysis Of Vertical Industrial Pressure Vessel Resting On Load Cells Subjected To A Seismic Load., Kameron W. Nez

College of Graduate Studies: Theses & Dissertations

Instability of structures, such as large vertical pressure vessels, is always an issue under the seismic load. In this current work, the acceleration that causes instability for a vertical pressure vessel has been determined experimentally using scaled models. This instability is caused by the tipping of the tall structure that is not completely fixed to the ground. This method is applied for three different sizes of pressure vessels, representing 50 CuFt to 1100 CuFt full scale models. These experimental results are compared with theoretical models. Using dimensional analysis, the accelerations that will cause the instability in the actual full-size models …

Actuator Optimization And Control Of Pediatric Knee Exoskeleton For Community-Based Mobility Assistance: More Lightweight, More Affordable, And More Stable, Sainan Zhang

Dissertations and Theses

Lightweight and smart exoskeletons offer the potential to improve mobility in children. State-of-the-art pediatric exoskeletons are typically clinic-based since they are either tethered or portable but cumbersome, and their design is often not optimized across a range of environments and users. Child growth progressively alters key exoskeleton design requirements, yet no prior work investigated actuator optimization to accommodate child growth. Moreover, exoskeletons typically use the torque sensor or spring mechanics as exteroceptive feedback, but these torque sensing methods not only lead to extra cost and mass but also cause a small range of stable controller gains.

To facilitate pediatric exoskeleton …

Optimizing Transcranial Focused Ultrasound: Calibration, Neuro Navigation, And Bold Fmri Evidence Of Neuromodulation, Amilcar J. Malave

Dissertations and Theses

This thesis presents the development, calibration, and initial implementation of transcranial focused ultrasound (tFUS) for neuromodulation in a human study. The primary objectives were to design a system capable of delivering precise and safe ultrasound stimulation to targeted brain regions and to conduct preliminary trials to assess its effects on brain activity. A custom calibration device was developed to ensure accurate measurement of acoustic pressure, addressing challenges such as voltage alterations caused by changes in system impedance. Additionally, a neuro-navigation tool was created to facilitate precise targeting of the right subgenual anterior cingulate cortex (right sgACC), enabling accurate placement of …

Path Instabilities And Drag In The Settling Of Single Spheres, Facundo Cabrera-Booman, Nicolas Plihon, Mickael Bourgoin

Mechanical and Materials Engineering Faculty Publications and Presentations

The settling behavior of individual spheres in a quiescent fluid was studied experimentally. The dynamics of the spheres was analyzed in the parameter space of particle-to-fluid density ratio (Γ) and Galileo number (Ga), with Γ ∈ (1.1,7.9) and Ga ∈ (100,340). The experimental results showed for the first time that the mean trajectory angle with the vertical exhibits a complex behavior as Ga and Γ are varied. Numerically predicted regimes such as Vertical Periodic for low Γ values, and Planar Rotating for high Γ values were validated. In particular, for the denser spheres, a clear transition from planar to non-planar …

Barriers And Variable Spacing Enhance Convective Cooling And Increase Power Output In Solar Pv Plants, Brooke Stanislawski, Todd Harman, Raul Bayoan Cal, Marc Calaf

Mechanical and Materials Engineering Faculty Publications and Presentations

When the temperature of solar photovoltaic (PV) modules rises, efficiency drops and module degradation accelerates. Thus, it is beneficial to reduce module operating temperatures. Previous studies of solar power plants have illustrated that incoming flow characteristics, turbulent mixing, and array geometry can strongly impact convective cooling, as measured by the convective heat transfer coefficient h. In the fields of heat transfer and plant canopy flow, previous work has shown that system-scale arrangement modifications—e.g., variable spacing, barriers, or windbreaks—can passively alter the flow, enhance turbulent mixing, and influence convection. However, researchers have not yet explored how variable spacing or barriers …

1d Granular Chains Of Closed-Cell Pvc Foams Under Low And Medium Velocity Impacts, Vikranth Kumar Reddy Madhirala

Open Access Dissertations

Chapter 1: This study experimentally analyses the deformation and energy retention behavior often closed-cell PVC foam disks constituting a one-dimensional granular chain subjected to low-velocity impacts. A pressure-driven impactor loads disk chains of two densities, each at 1 and 10 m/s. The deformations of the disks are captured using high-speed cameras, and the chain’s input and output forces are recorded during the impact. Energy retained by the chain and the disks is calculated using the deformations of the disks, input, output, and contact forces. The results show that the energy retained by the chain of H130 foam is 3 …

A Strategic Framework For Estimating International Container Flows: An Empirical Study, Dung-Ying Lin, Hsin-Chun Huang, Steven Travis Waller, Xiang Zhang

Journal of Marine Science and Technology–Taiwan

Maritime transportation is a highly complex transportation system that plays a pivotal role in international trade. Its low-cost and high-volume advantages have enabled it to cover most of the world’s cargo transportation. However, with the trend of global trade volume increasing almost every year and the recent congestion of ports due to the COVID-19 pandemic, the chaos in global supply chains not only increases operating costs for shippers but also makes it difficult for countries that rely heavily on port trade to plan for their ports’ future. To develop a strategic analytic tool to estimate container flow in liner shipping, …

An Application Of Cfd To Support The Development Of Treatment Strategies And Technology For The Management Of Cystic Fibrosis In Pediatric Patients, Morgan L. Thomas

Theses and Dissertations

Inhaled medications are a key treatment modality in multiple lung-related diseases and disorders. Considering children with cystic fibrosis (CF), improvements in the delivery of aerosol antibiotics have the potential to better eradicate bacterial lung infections, preserve lung function and thereby further extend lifespans and quality of life. The overall objective of this dissertation was to expand and validate CFD models for predicting the deposition of pharmaceutical aerosols throughout the airways and apply these models to understand the targeted delivery of inhaled antibiotics to children with CF. To accomplish this goal, three contributions were made. First, CFD methodologies for modeling aerosol …

A Bi-Invariant Approach To Approximate Motion Synthesis Of Planar Four-Bar Linkage, Tianze Xu, David H. Myszka, Andrew P. Murray

Mechanical and Aerospace Engineering Faculty Publications

This paper presents a planar four-bar approximate motion synthesis technique that uses only pole locations. Synthesis for rigid-body guidance determines the linkage dimensions that guide a body in a desired manner. The desired motion is specified with task positions including a location and orientation angle. Approximation motion synthesis is necessary when an exact match to the task positions cannot be obtained. A linkage that achieves the task positions as closely as possible becomes desired. Structural error refers to the deviations between the task positions and the linkage's generated positions. A challenge in approximate motion synthesis is that structural error involves …

Characterization Of Upper Extremity Kinematics Using Virtual Reality Movement Tasks And Wearable Imu Technology, Skyler A. Barclay, Lanna N. Klausing, Tessa M. Hill, Allison L. Kinney, Timothy Reissman, Megan E. Reissman

Mechanical and Aerospace Engineering Faculty Publications

Task-specific training has been shown to be an effective neuromotor rehabilitation intervention, however, this repetitive approach is not always very engaging. Virtual reality (VR) systems are becoming increasingly popular in therapy due to their ability to encourage movement through customizable and immersive environments. Additionally, VR can allow for a standardization of tasks that is often lacking in upper extremity research. Here, 16 healthy participants performed upper extremity movement tasks synced to music, using a commercially available VR game known as Beat Saber. VR tasks were customized to characterize participants' joint angles with respect to each task's specified cardinal direction (inward, …

Observability-Aware Path Planning For Autonomous Navigation, Raymond Brink Neistat

Open Access Master's Theses

Terrain-Aided Navigation (TAN) is a popular method of localization for GPS-denied vehicles, particularly in the marine domain. There are many ways to perform TAN in a marine setting, such as Bathymetric SLAM (BSLAM) and Bayesian Filtering with the aid of an a priori map. These techniques have been studied extensively, but show an overall lack of rigorous observability analyses. Without nonlinear observability analyses, TAN practitioners do not have an analytical indicator to know which areas of terrain will provide opportunities for the best localization performance. This thesis reviews current developments in the endeavors of nonlinear observability analyses as well as …

Control Of Flow Instabilities With Acoustic Metamaterials, Jensen E. Mctighe

Open Access Master's Theses

Acoustic metamaterials (AMs) have been proposed for uses in flow control, as they offer a passive control method and can be engineered independently, without needing complex fluid structure interactions simulations. For example, AMs embedded into flat plate surfaces have been demonstrated to delay (or speed up) the onset of laminar-to-turbulent boundary layer transition by attenuating (or strengthening) Tollmein-Schlicting waves through numerical simulation. However, as of present, no experimental research has been conducted to study or demonstrate the behaviors of AMs designed to interact with flow structures. An experiment was performed in which an AM was embedded into a flat plate …

Instantaneous Generation Of Subject-Specific Finite Element Models Of The Hip Capsule, Ahilan Anantha-Krishnan, Casey A. Myers, Clare K. Fitzpatrick, Chadd W. Clary

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Subject-specific hip capsule models could offer insights into impingement and dislocation risk when coupled with computer-aided surgery, but model calibration is time-consuming using traditional techniques. This study developed a framework for instantaneously generating subject-specific finite element (FE) capsule representations from regression models trained with a probabilistic approach. A validated FE model of the implanted hip capsule was evaluated probabilistically to generate a training dataset relating capsule geometry and material properties to hip laxity. Multivariate regression models were trained using 90% of trials to predict capsule properties based on hip laxity and attachment site information. The regression models were validated using …

Ifn-𝜸 And Il-10 Immunosensor With Vertically Aligned Carbon Nanotube Interdigitated Electrodes Toward Pen-Side Cattle Paratuberculosis Monitoring, Shaowei Ding, Benjamin J. Brownlee, Kshama Parate, Cicero C. Pola, Bolin Chen, Jesse M. Hostetter, Douglas Jones, John Jackman, Brian D. Iverson, Jonathan C. Claussen

Faculty Publications

Highly sensitive vertically aligned carbon nanotube arrays (VANTAs) interdigitated electrode (IDE) arrays are developed for electrochemical biosensing of two cytokines (i.e., interleukin-10 (IL-10) and interferon-gamma (IFN-𝜸)) that are useful for early detection Johne’s disease (Bovine Paratuberculosis) in cattle. The high aspect ratio VANTA-IDEs (50–60 μm in height) are grown through a chemical vapor deposition process from an iron (Fe) catalyst that is lithographically patterned on a silicon wafer with equal finger width and inter-finger spacing of 25 μm. After functionalization with distinct antibodies the VANTA-IDEs are capable of selective detection of both IL-10 and IFN-𝜸 within an actual biological matrix …

A Physical Test Artifact For Evaluating Edge Cases Of Individual And Fused Automated Driving Perception Sensors, Colin Schaefer

Dissertations, Master's Theses and Master's Reports

With the advent of technologies to support autonomous vehicles (AVs), the number of different AV models from a variety of companies and organizations has proliferated. With this increase in options comes the need to physically evaluate their perception systems. However, there is a lack of standard methods to physically evaluate these perception systems. A set of test artifacts can be used to compare the performances of perception systems, but the artifacts must be usable with different types of perception sensors and various sensor fusion systems. This thesis presents the development of an artifact that injects edge case scenarios into the …

High Temperature Strength Reduces Soldering In Aluminum High Pressure Die Casting, Jacob A. Belke

Dissertations, Master's Theses and Master's Reports

Die soldering, an adhesion defect in high pressure die casting (HPDC), is a symptom of localized sticking where a localized portion of the cast material is adhered to the tooling surface causing build up over time. This requires the tooling to be serviced which incurs additional costs to the process that gets passed on to the parts. Historically, soldering has been mitigated using lubricants, coatings, and alloy chemistry modifications but solder persists.

The Tresca friction thermomechanical model suggests soldering occurs when the local interfacial shear stress between the casting and die surface exceeds the local shear strength of the casting. …

Study Of Nanoparticle Dispersed Phase Change Materials And The Impact Of Temperature Gradient On The Potential For Particle Migration, Udit Sharma

Dissertations, Master's Theses and Master's Reports

Supercooling in phase change materials (PCMs) and the associated challenges in enhancing thermal conductivity through nanoparticle dispersion prompted this investigation. Existing literature exhibits inconsistencies in thermal conductivity improvements, suggesting a potential correlation with nanoparticle migration induced by thermophoresis. To address this, a novel temperature-dependent scaling parameter, \(\xi\), was introduced to predict particle migration propensity. A strong association was observed between higher \(\xi\) values and diminished thermal conductivity enhancements, indicating a significant influence of nanoparticle movement on heat transfer.

To further elucidate this relationship, a Nanoparticle Interaction Parameter \(N_\text{{pl}}\) was developed, incorporating critical fluid properties and interfacial effects. The derived critical …

An Elasto-Plastic Constitutive Model With Phase-Field Fracture For Additively Manufactured Metallic Materials, Nolan Ruble

Dissertations, Master's Theses and Master's Reports

The advent of additive manufacturing (AM), commonly known as 3D printing, has revolutionized the production of metallic components across various industries. This technology, which builds objects layer by layer, has shifted paradigms in manufacturing, allowing for unprecedented design freedom, material efficiency, and rapid prototyping. Metal additive manufacturing, in particular, has shown remarkable promise due to its ability to produce complex geometries that are difficult or impossible to achieve with traditional subtractive methods. In addition, additively manufactured (AM) materials are gaining popularity in thanks to their often superior and controllable properties in comparison to their wrought counterparts. In the present work, …

Modeling Pulsatile Flows Using Truly Incompressible Finite Volume Lattice Boltzmann Model, Akshay S. Dongre

Dissertations, Master's Theses and Master's Reports

The present study addresses the compressibility error inherent in the standard Lattice Boltzmann Method (LBM) and LBM’s restriction to uniform Cartesian meshes. To mitigate the compressibility error, an incompressible LBM (iLBM) model has been incorporated into the finite volume framework using a cell-centered finite volume approach, leveraging the simplicity of the LBM algorithm for irregularly shaped flow domains with unstructured meshes. Monotonic Upstream-centered Scheme for Conservation Laws (MUSCL) and linear reconstruction (LR) schemes have been used to compute convective fluxes across the cell interfaces with boundary conditions implemented using the second-order accurate Non-Equilibrium Extrapolation (NEE) method.

The finite volume iLBM …

Phase Field Modeling Of Fracture And Phase Separation Using Numerical Methods And Machine Learning, Revanth Mattey

Dissertations, Master's Theses and Master's Reports

Phase field modeling is a crucial tool in scientific and engineering disciplines due to its ability to simulate complex phenomena like phase transitions, interface dynamics, and pattern formation. It plays a vital role in understanding material behavior during processes such as solidification, phase separation, and fracture mechanics. Particularly in fracture mechanics, phase field modeling can be utilized to predict the crack path in complex materials. Understanding the failure behavior is vital for applications of any material. The specific contributions to the field of phase field fracture mechanics, are, Firstly, we propose a novel phase field fracture model to simulate the …

Exploring Market Segmentation For Autonomous Ferries, Ashari Fitra Rachmannullah, Taih Cherng Lirn, Kuo Chung Shang

Journal of Marine Science and Technology–Taiwan

This study aims to investigate the determinants that underlie psychographic segmentation in the domain of autonomous ferries (AFs) by using the theory of planned behaviour (TPB) as a guiding theoretical construct. The paper focuses on Indonesian individuals who had previously utilised conventional ferry services. TPB was applied as a catalyst to identify possible market segmentation among potential AF passengers. In this study, cluster analysis is used to differentiate passengers by their perception of using AFs. The results identified three market segments through cluster analysis based on passengers’ perceptions of using AFs: Resource-Limited, Resource-Capable, and Value-Optimistic. Among these segments, the Resource-Capable …

Adaptive Prediction Horizon Energy-Saving Collision-Free Mpc Of Ships Based On Ship-Shore Cooperation, Han Xue, Enjie Yang

Journal of Marine Science and Technology–Taiwan

ABSTRACT:In order to perform the close association between ship maneuvering control and energy consumption through the control strategy, this paper designs an adaptive prediction horizon based energy-saving robust nonlinear model predictive control (APHERNMPC) for underactuated ships to deal with the actual control and state constraints during berthing based on ship-shore cooperation. An improved Emperor Penguin Optimizer (EPO) method is proposed for collision avoidance decision. To solve the problems of falling into local optimum and reducing the convergence speed, the traditional EPO is improved based on Sobol sequence in order to enhance the diversity and ergodicity of the population. The multi-ship …

Research And Design A Lifeboat Virtual Reality Simulation System For Maritime Safety Training In Vietnam, Nguyen Dinh Thach, Nguyen Van Hung

Journal of Marine Science and Technology–Taiwan

Ensuring maritime safety and security is crucial for all nations. Training trainees and operational officers in this field aims to enhance their professional skills and ability to manage and resolve incidents at sea. This article outlines the development of a lifeboat simulation system that integrates Virtual Reality (VR) technology in accordance with international maritime regulations. It describes the creation of an algorithm designed to optimize data transmission between simulation systems using the ant colony optimization technique in conjunction with intelligent control algorithms on Unity 3D software for human interaction. In particular, the system combines training with a maritime simulation framework …

Characterization Of Magnetically Stabilized Hinges For Origami-Inspired Mechanisms, Larry L. Howell, H T. Pruett, Philip Klocke, Spencer Magleby

Faculty Publications

Origami-inspired mechanisms provide opportunities for deployable systems, including reflectarray antennas. There is a need for approaches to deploy and stabilize such arrays. Magnetic mechanisms show promise for meeting those needs and methods for modeling their behavior would facilitate their design and analysis. We demonstrate the existence of bistability in select configurations of magnetically stabilized hinges and characterize their equilibrium positions as a function of parameters estimated from simulation data for these mechanisms. Other relevant information such as potential energy, axial force data, angular position of unstable equilibria, and transition values from bistability to monostability are also modeled. The results are …

Nebraska Test #2289: Case Ih Steiger 525 Rowtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Nebraska Test #2288: Case Ih Steiger 475 Rowtrac, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Tractor Test 2281: John Deere 9rt 540 Diesel, Nebraska Tractor Test Lab

Nebraska Tractor Tests

ABOUT THE TEST REPORT AND USE OF THE DATA The test data contained in this report are a tabulation of the results of a series of tests. Due to the restricted format of these pages, only a limited amount of data and not all of the tractor specifications are included. The full OECD report contains usually about 30 pages of data and specifications. The test data were obtained for each tractor under similar conditions and therefore, provide a means of comparison of performance based on a limited set of reported data. EXPLANATION OF THE TEST PROCEDURES Purpose The purpose of …

Enhancing Robotic Exploration Through Semantically-Guided Sampling Strategies, Christopher Alexander Arend Tatsch

Graduate Theses, Dissertations, and Problem Reports (ETD)

From space and deep-sea exploration to disaster response and environmental monitoring, autonomous robots are essential for advancing science, improving safety, and addressing critical challenges. This dissertation introduces a novel open-source strategy for autonomous robotic exploration: the Semantically-Guided Exploration (SGE) framework. Designed for ground vehicles, SGE integrates semantic understanding into the autonomous exploration process, improving decision-making in complex environments. Specifically, the proposed sampling-based approach uses the information from the semantic segmentation of RGB images and depth images to guide the robot's selection of exploration goals. This method enables the robot to steer away from potential dangers such as large rocks and …

Bridging Evolutionary And Bayesian Optimization For Enhanced Safety Verification In Control Systems, Joshua M. Yancosek

Graduate Theses, Dissertations, and Problem Reports (ETD)

The rigorous safety verification of control systems in critical applications is essential, given their in creasing complexity and integration into everyday life. Simulation-based falsification approaches play a pivotal role in the safety verification of control systems, particularly within critical applications. These methods systematically explore the operational space of systems to identify configurations that result in violations of safety specifications. However, the effectiveness of traditional simulation based falsification is frequently limited by the high dimensionality of the search space and the sub stantial computational resources required for exhaustive exploration. This thesis presents Bayesian Evolutionary Approach for COuNterexample, or BEACON, a novel …