Mechanical Engineering Commons^™

Research On Strategies For High Quality Development Of New Power Systems, Xiaohong Chen, Junpeng Li, Yongmei Liu

Bulletin of Chinese Academy of Sciences (Chinese Version)

New power systems are at a critical stage of transition from theory to implementation. Against the backdrop of accelerating global energy transformation and technological revolution, shifting the energy system from “scale-oriented” to “quality-driven” is both an urgent need and a key focus for advancing the high-quality development of China’s new power systems. This study employs a four-dimensional analytical framework integrating “technology-elements-industry-green transition” to identify the main challenges existing in the new power systems currently, including constraints in key technologies, imbalances in factor allocation, difficulties in industrial coordination, and instability in power supply structure. Targeted measures are proposed accordingly. (1) Strengthening …

Quasi-Static Indentation Characteristics Of Foam-Filled Sandwich Composite Structures With Additively Manufactured Cfrp And Gfrp Corrugated Cores, S.Z.H. Shah, Juhyeong Lee, Khurram Altaf, M. Mohammad, M.Z. Hussain, R.S. Choudhry

Mechanical and Aerospace Engineering Faculty Publications

This paper presents an experimental investigation on the quasi-static indentation performance of polyurethane (PU) foam-filled carbon fibre-reinforced polymer (CFRP) and glass fibre-reinforced polymer (GFRP) corrugated sandwich composite structures (SCSs) under different indenter tip geometries (conical, trapezoidal, hemispherical, pyramidal, and cylindrical shapes). The SCSs were produced using hybrid manufacturing methods: (1) the facesheets were fabricated using the vacuum-assisted resin infusion (VARI) process, (2) the CFRP and GFRP corrugated cores were additively manufactured using the fused filament fabrication (FFF) process, and (3) the self-expanding PU foam-filled the open spaces in the core. The results elucidated that the indenter tip geometry and core …

Measuring And Modeling Grease Degradation, Alan Gurt

LSU Doctoral Dissertations

Lubricating grease is an ideal lubricant for many devices such as roller bearings, journal bearings, slide bearings, gears, and many types of joints due to its simplicity. Once grease is put in place, it can often provide adequate lubrication for extended periods of time without the need for a complex supply system that would generally be needed for oil lubrication. However, during prolonged use, various degradation mechanisms change the physical and chemical properties of grease, possibly leading to inadequate performance and machinery failure.

In order to succinctly quantify the degradation of grease, it is essential to have robust, meaningful test …

Mitigation Of The Environmental Impacts Of Lithium Extraction And Lithium Battery Manufacturing, Dominick R. Strollo

Sustainability Conference

Lithium extraction and the production methods utilized for lithium-ion batteries can have a large impact on the areas directly surrounding them, and if not mitigated properly, the rest of the world as well. For these batteries to be produced, lithium must be mined and refined from sources all around the world. The main concern of lithium mines is their impact on the water cycle and the surrounding water tables due to the heavy metals involved in the process and the sheer amount of water required. Production of the batteries themselves using the lithium slurry is far less impactful on the …

Computational Design Of Complex Concentrated Alloys, Hamid Sharifi

Doctoral Dissertations

A high-throughput parameterization of modified embedded atom model (MEAM) interatomic potentials for combinations of Cu, Ti, Ni, Cr, Co, Al, Fe, and Mn was carried out using a genetic algorithm. Unary systems were parameterized based on DFT calculations and experimental results. MEAM potentials for 28 binary and 56 ternary combinations of the elements were parameterized to DFT results that were carried out with semi-automated frameworks. Specific attention was made to reproduce properties that impact compositional segregation, material strength, and mechanics. Utilizing the MEAM interatomic potentials and a Monte Carlo scheme, phase segregation in the CrNiCo, CuNiCr and CuNiCo fcc alloys …

Experimental And Numerical Investigation Of Droplet Dynamics In Microscale Systems: The Influence Of Surfactants And Nanoparticles On Environmental Applications, Negin Bahadori

Master's Theses

Emulsions are suspensions of droplets dispersed into an immiscible liquid phase, with at least a water phase and an oil phase. The capability to incorporate both hydrophilic and hydrophobic components makes emulsions amenable to a variety of applications, such as bilgewater treatment and oil recovery. To optimize bilgewater treatment or oil recovery, many aspects must be considered, such as the effect of emulsion stability, the wetting conditions and, more in general, the possibility to characterize droplet’s behavior over static or dynamic conditions. This thesis investigates the roles of surfactants and nanoparticles in understanding droplet behavior in oil-water systems, with a …

Machine Learning-Driven Process Analysis And Optimization In Solid-State Welding And Fusion-Based Additive Manufacturing, Radif Uddin Ahmed

Master's Theses

In the modern era of advanced manufacturing, optimizing process parameters is pivotal in ensuring the quality and reliability of sophisticated component fabrication. This study presents a novel, data-driven approach to parameter optimization in two cutting-edge manufacturing techniques: Friction Stir Welding (FSW) and Laser Powder Bed Fusion (LPBF). By leveraging machine learning methodologies, this research addresses the critical challenge of efficiently determining optimal process parameters, a task traditionally relying on time-consuming and resource-intensive trial-and-error methods. This study will lead to a robust data-driven framework for process analysis of more advanced manufacturing techniques like the Additive Friction Stir Deposition (AFSD) process. Friction …

Optimizing Electric Vehicle Fleet Integration In Industrial Demand Response: Maximizing Vehicle-To-Grid Benefits While Compensating Vehicle Owners For Battery Degradation, Andre Leippi, Markus Fleschutz, Kevin Davis, Anna-Lena Klingler, Michael D. Murphy

Publications

This paper addresses the integration of electric vehicle (EV) fleets into industrial smart grids to increase operational flexibility. It focuses on an extended multi-objective optimization problem that minimizes two primary objectives: (i) the electricity expenditure of a company using its employees’ EV batteries as temporary distributed energy storage, and (ii) the costs associated with the degradation of EV batteries, given the additional usage from the company’s perspective. In this paper, the utilization of an EV fleet is simulated at the individual car level over a one-year period. These optimization problems were balanced by using real-time electricity prices and the effective …

Robust Data-Driven Run-To-Run Control Via One-Step Constrained Optimization For Automated Serial Sectioning, Rhianna M. Oakley

Mechanical Engineering ETDs

This Thesis develops a one-step predictive run-to-run controller (R2R-MPC) for automating a mechanical serial sectioning (MSS) system. MSS is a destructive material analysis process that iteratively removes slices of material and captures 2D images, reconstructing them into 3D representations. Commonly used in material science for characterizing materials and failure analysis, MSS typically operates in an open-loop fashion, which experiences high variability in material removal due to system disturbances. To address this, a robust closed-loop R2R-MPC is presented, modeling MSS process uncertainty using a linear differential inclusion identified from operational historical data. The R2R-MPC is posed as an optimization problem that …

Collapse Of Pre-Covid-19 Differences In Performance In Online Vs. In-Person College Science Classes, And Continued Decline In Student Learning, Gregg R. Davidson, Hong Xiao, Kristin Davidson

Faculty and Student Publications

Abstract: Studies comparing student outcomes for online vs. in-person classes have reported mixed results, though with a majority finding that lower-performing students, on average, fare worse in online classes, attributed to the lack of built-in structure provided by in-person instruction. The online/in-person outcome disparity was normative for non-major geology classes at the University of Mississippi prior to COVID-19, but the difference disappeared in the years after 2020. Previously distinct trendlines of GPA-based predictions of earned-grade for online and in-person classes merged. Of particular concern, outcomes for in-person classes declined to match pre-COVID-19 online expectations, with lower-GPA students disproportionally impacted. Objective …

Fringe-Field Actuation Of Mems Cantilever Resonators: Capacitance Model For Frequency-Amplitude Response Of Parametric Resonance, Miguel A. Martinez, Dumitru I. Carantu

Mechanical Engineering Faculty Publications

The paper investigates the frequency-amplitude response of micro-electromechanical system (MEMS) cantilever beams, which are actuated by the fringe field at parametric resonance. In this design, a micro cantilever beam (flexible electrode) and a ground plate (fixed electrode) are placed in parallel and connected through an AC voltage. The electrostatic force is due to electric field lines within the volume directly between the cantilever and the ground plate. The parallel-plate capacitance is directly related to the overlapping area of the two electrodes. However, to accurately compute the capacitance of the two electrodes, the effects due to the fringing field must be …

Electrostatically Actuated Bio-Mems Circular Membrane Resonator Sensors: Voltage Response Of Primary Resonance, Dumitru I. Caruntu, Marcos Alipi

Mechanical Engineering Faculty Publications

This paper deals with the voltage-amplitude relationship during the primary resonance of electrostatically actuated circular membrane resonator sensors within the context of BIO-MEMS. The motion of these membranes is governed by a partial differential equation, which is nondimensionalized for analysis. This equation incorporates both damping effects and soft electrostatic actuation. The actuation AC frequency is set close to half of the membrane’s first natural frequency, leading to primary resonance. To investigate membrane’s voltage response, two principal methods were employed: the method of multiple scales (MMS) and a reduced order model (ROM) that incorporates two modes of vibration. This research provides …

Sediment Transport On Rippled Beds, Octavio Guevara, L. Guan, J. S. Salinas, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We conduct an Euler-Lagrange, direct numerical simulation of a turbulent channel flow at a shear Reynolds number of Reτ=180 over an erodible particle bed. The particle bed consists of approximately 1.3 × 10⁶ monodisperse particles, resulting in a bed thickness of around 12–13 particles. The particle density and size are chosen to achieve a ratio of 4 for the Shields stress to the critical Shields stress necessary for incipient motion such that particle transport occurs primarily as bedload. The simulation is run long enough for ripples to form. We track the temporal evolution of the particle flux and excess …

Control Of Multiagent Networks With Misbehaving Nodes, Emre Yildirim

USF Tampa Graduate Theses and Dissertations

The overarching objective of this dissertation is to introduce system theoretical frameworks in control of misbehaving multiagent networks subject to limited resources (i.e., limited number of driver nodes), and the presence of disturbances and/or uncertainties (i.e., misbehaving nodes). Below, we briefly summarize each problem studied in this dissertation with their proposed solutions.

Specifically, we first consider multiagent networks subject to misbehaving nodes over fixed undirected graph topologies. To address this problem, we apply proportional-integral control signals to a subset of nodes (i.e., driver nodes) in the network to address the undesired effects arising from misbehaving nodes. Since multiagent networks with …

The Impact Of Hearing Aid User Speech On Environment Classification And Own Voice Listener Preferences, Robert Andrew Budinsky Iii

USF Tampa Graduate Theses and Dissertations

Hearing aids (HA) have improved over the past few decades with advanced signal processing, such as environment classification and background noise reduction, but are still limited by challenges related to when the user is speaking. These challenges include the potential interference a HA user’s voice has on device environment classification and the potential influence a HA has on own voice (OV) sound quality. However, the effects of OV on HA environment classification and signal processing are not well established, nor are the desired HA program settings regarding OV listening preferences. In this study, a combination of electroacoustic and behavioral methods …

A Study Of Fit And Friction Force As A Function Of The Printing Process For Fff 3d-Printed Piston–Cylinder Assembly, Philippe A. Passeraub, Quentin Allen, Elizabeth Clark, Michael Miles, Siddartha Berns, Maija Pearson, Sterling Allred, Jonah Brooks, Sylvain Hugon

ScholarsArchive Data

Dataset DOI: https://doi.org/10.26067/hjm6-3d45

The shared data comprises the experimental measurements performed presented in the figures 5, 6, 7, 9, 10, 11, 12, and in the tables for the following article:

Passeraub, P.A.; Allen, Q.; Clark, E.; Miles, M.; Berns, S.; Pearson, M.; Allred, S.; Brooks, J.; Hugon, S. A Study of Fit and Friction Force as a Function of the Printing Process for FFF 3D-Printed Piston–Cylinder Assembly. J. Manuf. Mater. Process. 2024, 8, 249. https://doi.org/10.3390/jmmp8060249

Active Grid Turbulence Anomalies Through The Lens Of Physics Informed Neural Networks, Sofía Angriman, Sarah E. Smith, Patricio Clark Di Leoni, Pablo J. Cobelli, Pablo D. Mininni, Martín Obligado

Mechanical and Materials Engineering Faculty Publications and Presentations

Active grids operated with random protocols are a standard way to generate large Reynolds number turbulence in wind and water tunnels. But anomalies in the decay and third-order scaling of active-grid turbulence have been reported. We combine Laser Doppler Velocimetry and hot-wire anemometry measurements in a wind tunnel, with machine learning techniques and numerical simulations, to gain further understanding on the reasons behind these anomalies. Numerical simulations that incorporate the statistical anomalies observed in the experimental velocity field near the active grid can reproduce the experimental anomalies observed later in the decay. The results indicate that anomalies in experiments near …

Theoretical And Numerical Investigation Of An Ultra-Broadband Near-Perfect Absorption In Auxetic Metamaterials, Md. Rezwan Ahmed, Oishi Jyoti,, Ferdous Farjana, Pritu P. Sarkar, Alok Kumar Paul, Md. Samiul Habib

Mechanical Engineering Faculty Publications

In this paper, we present and numerically investigate an auxetic metamaterial absorber based on vanadium dioxide (VO2), achieving more than 90% absorption of the incident terahertz (THz) waves between 4.15 THz to 8.43 THz with an average absorption of 98.4%. To our knowledge, the absorption bandwidth is higher than previously reported VO2-based absorbers. The proposed absorber contains two VO2 based resonator rings placed diagonally at the top of the dielectric substrate in such a way as to create an auxetic shape and provide more design space than the existing absorbers. Considering the vector nature of electromagnetic fields in three-dimensional space, …

Hypoxic Incubator: Improving Robustness/Reliability And Demonstrating Physiological Efficacy, Damon Dennis Tan

Master's Theses

The Microphysiological Systems Laboratory aims to develop colorectal cancer tumor models under a hypoxic environment to assess model response to pharmaceutical compounds in vitro. To perform relevant studies, researchers have attempted to use different hypoxic inducing strategies such as a nitrogen pod and hypoxic incubator to recreate in vivo physiological responses to hypoxia. However, studies would be interrupted due to incubator functionality failure. To ensure successful and physiologically relevant studies, I improved and verified the robustness and reliability of a hypoxic incubator previously designed and manufactured in the lab. Through the testing and iterating design processes, I engineered and implemented …

3d Printed Microfluidic Fabrication Methodology, Characterization, Mechanical Design, And Applications In Electrostatic Artificial Muscles And Benthic Microbial Fuel Cells, Terak B. Hornik

Master's Theses

The fabrication of microfluidic devices often requires specialized methods. The development of these methods requires careful characterization and understanding of the processes involved. Using primarily PolyJet 3D printing technology, microfluidics offers a wide scope of applications such as microfluidic benthic microbial fuel cells (MBMFCs) and electrostatic artificial muscles. MBMFCs benefit from the confinement of the microbes resulting in close proximity between the electrode and the organisms. Using a modular design called the Sponge, assembly and upscaling is possible. Electrostatic artificial muscles benefit from a microfluidic approach due to the non-linearity of electrostatic attraction creating disproportionate benefits when miniaturized. When designed …

Atmosphere Effects In Laser Powder Bed Fusion: A Review, Ben Brown, Cody Lough, Davis Wilson, Joseph Newkirk, Frank Liou

Materials Science and Engineering Faculty Research & Creative Works

The use of components fabricated by laser powder bed fusion (LPBF) requires the development of processing parameters that can produce high-quality material. Manipulating the most commonly identified critical build parameters (e.g., laser power, laser scan speed, and layer thickness) on LPBF equipment can generate acceptable parts for established materials and moderately intricate part geometries. The need to fabricate increasingly complex parts from unique materials drives the limited research into LPBF process control using underutilized parameters, such as atmosphere composition and pressure. As presented in this review, manipulating atmosphere composition and pressure in laser beam welding has been shown to expand …

Temperature Effect On The Properties And Response Of Composite Materials And Plates, Victor Birman

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The paper illustrates the effect of temperature on composite material properties and its influence on the response of composite plates. Two composites considered include laminae with uniaxially oriented and with in-plane randomly oriented fibers. Analytical solutions are presented for a uniformly heated large-aspect-ratio plate deforming into a cylindrical surface. The solutions are demonstrated for thermal buckling and natural frequencies for the cases of controlled loading and controlled displacements. Micromechanical residual and lifetime thermally induced stresses at the interface of fibers and matrix are assessed to predict a possible onset of local damage after the curing and during lifetime. The material …

Machine Vision To Provide Quantitative Analysis Of Meltpool Stability For A Coaxial Wire Directed Energy Deposition Process, Braden Mclain, Remy Mathenia, Todd Sparks, Frank Liou

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Wire-based additive manufacturing (AM) is at the forefront of complex metal fabrication because of its scalability for large components, potential for high deposition rates, and ease of use. A common goal of wire directed energy deposition (DED) is preserving a stable process throughout deposition. If too little energy is put into the deposition, the wire will stub into the substrate and begin oscillating, creating turbulence within the melt pool. If too much energy exists, the wire will overheat, causing surface tension to take over and create liquid drips as opposed to a solid bead. This paper proposes a computer vision …

Optimal Control Of Nonlinear, Nonautonomous, Energy Harvesting Systems Applied To Point Absorber Wave Energy Converters, Houssein Yassin, Tania Demonte Gonzalez, Kevin Nelson, Gordon Parker, Wayne Weaver

Michigan Tech Publications

Pursuing sustainable energy solutions has prompted researchers to focus on optimizing energy extraction from renewable sources. Control laws that optimize energy extraction require accurate modeling, often resulting in time-varying, nonlinear differential equations. An energy-maximizing optimal control law is derived for time-varying, nonlinear, second-order, energy harvesting systems. We demonstrate that sustaining periodic motion under this control law when subjected to periodic disturbances necessitates identifying appropriate initial conditions, inducing the system to follow a limit cycle. The general optimal solution is applied to two point absorber wave energy converter models: a linear model where the analytical derivation of initial conditions suffices and …

Development Of Multifunctional Wood Composites With Integrated Phase Change Materials For Enhanced Thermal Management, Self-Healing, And Sustainability., Emmanuel Igbokwe

LSU Master's Theses

Abstract

This study focused on incorporating self-healing, flame retardancy, and energy harvesting capabilities into the wood composite to contribute to more sustainable and energy-efficient building practices. Oriented strand board has been widely used as sheath for roofing or dry walls in residential buildings. Residential buildings account for a large portion of energy consumption. Therefore, an oriented strand board with energy harvesting capability is highly desired. Additionally, flame retardancy and damage self-healing and end-of-life recycling are also critical features for buildings.

In this study, we prepared a novel oriented strand board by constructing sandwich structures. The face sheets of the sandwich …

Lithicone-Protected Lithium Metal Anodes For Lithium Metal Batteries With Nickel-Rich Cathode Materials, Ridwan A. Ahmed, Kevin V. Carballo, Krishna P. Koirala, Qian Zhao, Peiyuan Gao, Ju-Myung Kim, Cassidy S. Anderson, Xiangbo Meng, Chongmin Wang, Ji-Guang Zhang, Wu Xu

Mechanical Engineering Faculty Publications and Presentations

The high energy density advantage of lithium (Li) metal batteries (LMBs) makes them increasingly desirable; however, problems such as strong reactivity and dendrite growth of Li metal anode limit their practical uses. In this work, a novel Li-containing glycerol (LiGL) or lithicone protection layer on a 50 μm thick Li metal anode is employed for improving the performance of LMBs. This LiGL layer was accurately deposited via a molecular layer deposition (MLD) process at 150°C, using lithium tert-butoxide and glycerol as precursors. The as-formed LiGL coating layer is highly tunable in its thickness by simply adjusting MLD cycles and shows …

Design And Implementation Of Attitude Control System For Gnssas 6u Cubesat, Anoud Nasser Alkatheeri

Theses

This thesis presents the design and simulation of the Attitude Control System (ACS) for the GNSSaS 6U CubeSat, developed by the National Space Science and Technology Center (NSSTC) at UAE University. The CubeSat's mission is to enhance GNSS signal accuracy, which requires precise attitude control to achieve this objective. The ACS utilizes magnetorquers and reaction wheels for actuation. The primary objective of this thesis is to design an ACS that fulfills the mission’s performance requirements, including maintaining pointing accuracy in both fine and medium pointing modes. To achieve this, a comprehensive disturbance analysis was conducted, leading to the selection of …

Smuggling Of Person By Sea In Southeast Asia : From Regional Perspective, Sovisal Srey

World Maritime University Dissertations

No abstract provided.

Implementation Of Mash Surrogate Test Vehicles For Sign Supports, Breakaway Poles, And Work Zone Traffic Control Devices, Mahfuza Rahman Doreen

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

This describes the development of two surrogate test vehicles, or "bogie vehicles," for performing compliance testing of breakaway devices found on the roadside according to the American Association of State Highway and Transportation Officials (AASHTO) Manual for Assessing Safety Hardware (MASH). Historically, surrogate vehicle testing and approval of roadside structures was not permitted, because critical vehicle behaviors could not be emulated using the existing or modified rigid frame structures. Therefore, Project NCHRP 22-55 was funded to develop two reusable bogie vehicles to emulate the MASH 1100C small car and 2270P pickup truck. This thesis describes the background data collection, initial …

Analysis, Design, And Experimental Validation Of The Thermal Subsystem Of Alainsat-1 Cubesat, Ameereh Seyedzadeh

Theses

This thesis investigates the thermal management techniques of AlAinSat-1 during extremely harsh space conditions. It presents a comprehensive analysis of its thermal behavior using numerical techniques and validates the CubeSat's survivability in space via experimental testing. AlAinSat-1 is a nanocube-shaped satellite carrying Earth observation payloads, including RITA (Remote sensing and Interference detector with radiome-Try and vegetation Analysis) and Locana. Understanding how the CubeSat behaves in harsh space conditions and maintains thermal stability during its mission is critical to its success. The main aim of this study is to employ finite element analysis (FEA) techniques to simulate the thermal behavior of …