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Articles 5431 - 5460 of 29998

Full-Text Articles in Mechanical Engineering

Investigating The Performance Of A Novel Multi-Element Airfoil Concept Using Numerical Analysis, Ahmed Elbaz Jul 2022

Investigating The Performance Of A Novel Multi-Element Airfoil Concept Using Numerical Analysis, Ahmed Elbaz

Mechanical Engineering

Separation control is one of the trending topics recently for Vertical Axis Wind Turbine (VAWT) applications, flow separation that occur on the suction side of an airfoil is a major limitation for VAWTs starting and power coefficient; passive control of flow separation has been attracting wind energy research community recently. The principle objective of this paper is to investigate the effect of the multi-element airfoil on the aerodynamic characteristics at wide range of angles of attack at a Reynolds number of 140,000. The multi element airfoil modification has been implemented by replacing the baseline airfoil with two airfoil members within …

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Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen Jul 2022

Control And Planning For Mobile Manipulators Used In Large Scale Manufacturing Processes, Joshua T. Nguyen

LSU Master's Theses

Sanding operations in industry is one of the few manufacturing tasks that has yet to achieve automation. Sanding tasks require skilled operators that have developed a sense of when a work piece is sufficiently sanded. In order to achieve automation in sanding with robotic systems, this developed sense, or intelligence, that human operators have needs to be understood and implemented in order to achieve, at the minimum, the same quality of work. The system will also need to have the equivalent reach of a human operator and not be constrained to a single, small workspace. This thesis developed solutions for …

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A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess Jul 2022

A Comparative Study On Representativeness And Stochastic Efficacy Of Miniature Tensile Specimen Testing, Sreekar Karnati, Sriram Praneeth Isanaka, Yunlu Zhang, Frank W. Liou, Jason L. Schulthess

Mechanical and Aerospace Engineering Faculty Research & Creative Works

In this article, a miniature dog bone tensile coupon design was tested against the existing ASTM standard specimen design. Specimens were prepared from commercially sourced austenitic stainless steel 304 alloy, and a defect-ridden additively manufactured 304L alloy was studied. By utilizing a tensile specimen design that is 1/230th volume of the smallest ASTM E8-04 (2016), Standard Test Methods for Tension Testing of Metallic Materials, dog bone specimen, coupled to a digital image correlation (DIC) setup, case studies were performed to compare tensile property measurements and strain field evolution. Whereas yield strength measurements were observed to be similar, post-yield, the ultimate …

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Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby Jul 2022

Predictive Thermal Modeling And Characterization Of Ultrasonic Consolidation Process For Thermoplastic Composites, Madeline Kirby

LSU Master's Theses

Ultrasonic consolidation (USC) of thermoplastic composites (TPCs) is a highly attractive and promising method to manufacture high-performance composites. This work focuses on USC of dry carbon fiber (CF) fabrics with high-temperature polyphenylene sulfide (PPS) films. Experimental trials to assess feasibility of the process are time-consuming. Consequently, a predictive thermal model would facilitate process parameters selection to reduce expensive trial-and-error approaches. This paper presents a 2D finite element model of samples under consolidation, incorporating equations for viscoelastic heating, matrix phase change, and material properties. Theoretical temperature profiles for nodes of interest were compared to the corresponding experimental temperature curves for various …

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Tunable Passive Shock And Vibration Isolators For Rotational Isolation, Chase B. Lemaire Jul 2022

Tunable Passive Shock And Vibration Isolators For Rotational Isolation, Chase B. Lemaire

LSU Master's Theses

Shock and vibration isolation are a critical need in helmets, which are widely used to protect athletes, workers, soldiers, and astronauts. Passive vibration isolation systems are a good option when mass and volume should be minimized and when the experienced loadings can be predicted. However, it is frequently challenging to find materials and structures which exhibit the optimal vibration and impact isolation properties for an application. As a case study illustrating a novel design paradigm for rotational shock absorption, a family of optimal solutions for the physical properties of American football helmets is presented. Lumped parameter Simulink models simulate a …

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Microfluidic Device For Localized Electroporation, Justin Brooks, Arian Jaberi, Ruiguo Yang Jul 2022

Microfluidic Device For Localized Electroporation, Justin Brooks, Arian Jaberi, Ruiguo Yang

Department of Mechanical and Materials Engineering: Faculty Publications

Electroporation is a common method of transfection due to its relatively low risk and high transfection efficiency. The most common method of electroporation is bulk electroporation which is easily performed on large quantities of cells yet results in variable levels of viability and transfection efficiency across the population. Localized electroporation is an alternative that can be administered on a similar scale but results in much more consistent with higher quality transfection and higher cell viability. This paper discusses the creation and use of a simple and cost-effective device using porous membrane for performing localized electroporation.

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Phase Space Analysis Of Nonlinear Wave Propagation In A Bistable Mechanical Metamaterial With A Defect, Mohammed A. Mohammed, Piyush Grover Jul 2022

Phase Space Analysis Of Nonlinear Wave Propagation In A Bistable Mechanical Metamaterial With A Defect, Mohammed A. Mohammed, Piyush Grover

Department of Mechanical and Materials Engineering: Faculty Publications

We study the dynamics of solitary waves traveling in a one-dimensional chain of bistable elements in the presence of a local inhomogeneity (`defect'). Numerical simulations reveal that depending upon its initial speed, an incoming solitary wave can get transmitted, captured or reflected upon interaction with the defect. The dynamics are dominated by energy exchange between the wave and a breather mode localized at the defect. We derive a reduced-order two degree of freedom Hamiltonian model for wave-breather interaction, and analyze it using dynamical systems techniques. Lobe dynamics analysis reveals the fine structure of phase space that leads to the complicated …

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Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors, Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, Austin Downey Jul 2022

Structural Health Monitoring Of Fatigue Cracks For Steel Bridges With Wireless Large-Area Strain Sensors, Sdiq Anwar Taher, Jian Li, Jong-Hyun Jeong, Simon Laflamme, Hongki Jo, Caroline Bennett, William N. Collins, Austin Downey

Faculty Publications

This paper presents a field implementation of the structural health monitoring (SHM) of fatigue cracks for steel bridge structures. Steel bridges experience fatigue cracks under repetitive traffic loading, which pose great threats to their structural integrity and can lead to catastrophic failures. Currently, accurate and reliable fatigue crack monitoring for the safety assessment of bridges is still a difficult task. On the other hand, wireless smart sensors have achieved great success in global SHM by enabling long-term modal identifications of civil structures. However, long-term field monitoring of localized damage such as fatigue cracks has been limited due to the lack …

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Micro Heat Exchanger To Cool Cerebrospinal Fluid For Brain Injury Treatment, Sachin Dahiya Jul 2022

Micro Heat Exchanger To Cool Cerebrospinal Fluid For Brain Injury Treatment, Sachin Dahiya

LSU Master's Theses

Hypothermia is accepted as a method to preserve cells and tissue. Clinical evidence shows that administration of hypothermia could lead to neuroprotection after cardiac arrest. Non-invasive methods such as surface cooling devices, drugs and cold liquid ventilation are available to induce hypothermia. These approaches for achieving hypothermia have not been optimized yet. The surface cooling methods are generally slow and may lead to additional thermal shock to the body. Here, we propose a rapid, selective cooling method for the brain using a micro heat exchanger to cool the cerebrospinal fluids (CSF). We designed and 3D printed a U-type heat exchanger …

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Efficiently Searching Extreme Mechanical Properties Via Boundless Objective-Free Exploration And Minimal First-Principles Calculations, Joshua Ojih, Mohammed Al-Fahdi, Alejandro David Rodriguez, Kamal Choudhary, Ming Hu Jul 2022

Efficiently Searching Extreme Mechanical Properties Via Boundless Objective-Free Exploration And Minimal First-Principles Calculations, Joshua Ojih, Mohammed Al-Fahdi, Alejandro David Rodriguez, Kamal Choudhary, Ming Hu

Faculty Publications

Despite the machine learning (ML) methods have been largely used recently, the predicted materials properties usually cannot exceed the range of original training data. We deployed a boundless objective-free exploration approach to combine traditional ML and density functional theory (DFT) in searching extreme material properties. This combination not only improves the efficiency for screening large-scale materials with minimal DFT inquiry, but also yields properties beyond original training range. We use Stein novelty to recommend outliers and then verify using DFT. Validated data are then added into the training dataset for next round iteration. We test the loop of training-recommendation-validation in …

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Lubrication Performance Of Sunflower Oil Reinforced With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas, Md Mashfiqur Rahman, Javier A. Ortega, Laura Peña-Parás, Demófilo Maldonado-Cortés, José A. González, Ricardo Cantú, Adrián Campos, Eugenio Flores Jul 2022

Lubrication Performance Of Sunflower Oil Reinforced With Halloysite Clay Nanotubes (Hnt) As Lubricant Additives, Md Abu Sayeed Biswas, Md Mashfiqur Rahman, Javier A. Ortega, Laura Peña-Parás, Demófilo Maldonado-Cortés, José A. González, Ricardo Cantú, Adrián Campos, Eugenio Flores

Mechanical Engineering Faculty Publications

This study evaluates the tribological performance of nanolubricants of a vegetable oil (sunflower oil) reinforced with different concentrations of environmentally-friendly nanoparticles of halloysite clay nanotubes (HNTs). Tribological characterization was performed under different conditions to determine its effect on the nanolubricants’ performance and optimal HNT concentration. The tribological performances under low and high contact pressures were analyzed with a block-on-ring tribometer following the ASTM G-077-05 standard procedure. The extreme pressure (EP) properties of the nanolubricants were determined with a T-02 four-ball tribotester according to the ITeE-PIB Polish method for testing lubricants under scuffing conditions. In addition, the lubrication performance of the …

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Incorporation Of Torsion Springs In A Knee Exoskeleton For Stance Phase Correction Of Crouch Gait, Katy Baker Bumbard, Harold Herrington, Chung-Hyun Goh, Alwathiqbellah Ibrahim Jul 2022

Incorporation Of Torsion Springs In A Knee Exoskeleton For Stance Phase Correction Of Crouch Gait, Katy Baker Bumbard, Harold Herrington, Chung-Hyun Goh, Alwathiqbellah Ibrahim

Mechanical Engineering Faculty Publications and Presentations

Crouch gait is a motor complication that is commonly associated with cerebral palsy, spastic diplegia, stroke, and motor-neurological pathologies, broadly defined as knee flexion in excess of 20° in the gait cycle. Uncorrected crouch gait results in fatigue, joint degradation, and loss of ambulation. Torsion springs have been used in cycling to store energy in the knee flexion to reduce fatigue in the quadriceps during knee extension. SolidWorks was used to design a passive exoskeleton for the knee, incorporating torsion springs of stiffnesses 20,000 N/mm and 30,000 N/mm at the knee joint, to correct four different crouch gaits. OpenSim was …

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Topological Supercavity Resonances In The Finite System, Lujun Huang, Bin Jia, Yan Kei Chiang, Sibo Huang, Chen Shen, Fu Deng, Tianzhi Yang, David A Powell, Yong Li, Andrey E Miroshnichenko Jul 2022

Topological Supercavity Resonances In The Finite System, Lujun Huang, Bin Jia, Yan Kei Chiang, Sibo Huang, Chen Shen, Fu Deng, Tianzhi Yang, David A Powell, Yong Li, Andrey E Miroshnichenko

Henry M. Rowan College of Engineering Departmental Research

Acoustic resonant cavities play a vital role in modern acoustical systems. The ultrahigh quality-factor resonances are highly desired for some applications such as high-resolution acoustic sensors and acoustic lasers. Here, a class of supercavity resonances is theoretically proposed and experimentally demonstrated in a coupled acoustic resonator system, arising from the merged bound states in the continuum (BICs) in geometry space. Their topological origin is demonstrated by explicitly calculating their topological charges before and after BIC merging, accompanied by charges annihilation. Compared with other types of BICs, they are robust to the perturbation brought by fabrication imperfection. Moreover, it is found …

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Large Scale Energy Signature Analysis: Tools For Utility Managers And Planners, Sukjoon Oh, John F. Gardner Jul 2022

Large Scale Energy Signature Analysis: Tools For Utility Managers And Planners, Sukjoon Oh, John F. Gardner

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Building energy signature analysis is a well-established tool for understanding the temperature sensitivity of building energy consumption and measuring energy savings. This tool has been used to measure energy savings of residential, commercial, and even industrial buildings. The public availability of electricity loads (i.e., hourly electricity demand (MW)) from entire Balancing Authorities (BAs) provide an interesting opportunity to apply this approach to a large aggregate load. In this paper, we explore that opportunity for BAs and show that the correlations for large geographical areas are surprisingly coherent when the change-point linear regression analysis is used with the daily interval data …

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Effects Of Pulsatile Flow Rate And Shunt Ratio In Bifurcated Distal Arteries On Hemodynamic Characteristics Involved In Two Patient-Specific Internal Carotid Artery Sidewall Aneurysms: A Numerical Study, Hang Yi, Mark Johnson, Luke C. Bramlage, Bryan Ludwig, Zifeng Yang Jul 2022

Effects Of Pulsatile Flow Rate And Shunt Ratio In Bifurcated Distal Arteries On Hemodynamic Characteristics Involved In Two Patient-Specific Internal Carotid Artery Sidewall Aneurysms: A Numerical Study, Hang Yi, Mark Johnson, Luke C. Bramlage, Bryan Ludwig, Zifeng Yang

Mechanical and Materials Engineering Faculty Publications

The pulsatile flow rate (PFR) in the cerebral artery system and shunt ratios in bifurcated arteries are two patient-specific parameters that may affect the hemodynamic characteristics in the pathobiology of cerebral aneurysms, which needs to be identified comprehensively. Accordingly, a systematic study was employed to study the effects of pulsatile flow rate (i.e., PFR−I, PFR−II, and PFR−III) and shunt ratio (i.e., 75:25 and 64:36) in bifurcated distal arteries, and transient cardiac pulsatile waveform on hemodynamic patterns in two internal carotid artery sidewall aneurysm models using computational fluid dynamics (CFD) modeling. Numerical results indicate that larger PFRs can cause higher wall …

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In-Situ Infrared Thermographic Inspection For Local Powder Layer Thickness Measurement In Laser Powder Bed Fusion, Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming-Chuan Leu Jul 2022

In-Situ Infrared Thermographic Inspection For Local Powder Layer Thickness Measurement In Laser Powder Bed Fusion, Tao Liu, Cody S. Lough, Hossein Sehhat, Yi Ming Ren, Panagiotis D. Christofides, Edward C. Kinzel, Ming-Chuan Leu

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The laser powder bed fusion (LPBF) process is strongly influenced by the characteristics of the powder layer, including its thickness and thermal transport properties. This paper investigates in-situ characterization of the powder layer using thermographic inspection. A thermal camera monitors the temperature history of the powder surface immediately after a layer of new powder is deposited by the recoating system. During this process, thermal energy diffuses from the underlying solid part, eventually raising the temperature of the above powder layer. Guided by 1D modeling of this heat-up process, experiments show how the parameterized thermal history can be correlated with powder …

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Jme 4110: Battery Operated Extendable Limb Shears, James Lehn, Ngoc Nguyen, Cory Sellers, Larissa Wells Jul 2022

Jme 4110: Battery Operated Extendable Limb Shears, James Lehn, Ngoc Nguyen, Cory Sellers, Larissa Wells

Washington University / UMSL Mechanical Engineering Design Project JME 4110

This project entails the design, analysis, and construction process of battery operated extendable limb shears. The design consists of shears mounted on top of extendable poles and is powered by a DeWalt hand-held drill mounted on a manufactured steel box. By using the mechanics of pulleys and tension force, the shears can cut branches up to 1.5 inches in diameter and as tall as 16 feet above the ground.

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Pressure Disturbance Upstream Of The Boundary Layer Data System, Michelle S. Leclere Jul 2022

Pressure Disturbance Upstream Of The Boundary Layer Data System, Michelle S. Leclere

Master's Theses

The primary objective for this work was to evaluate the reliability of computational fluid dynamics (CFD) tools in the prediction of upstream surface pressure disturbance and pressure drag of various instrument excrescence shapes for a small aircraft flight test device called the Boundary Layer Data System (BLDS). Insights on pressure disturbance will serve as a guide for the placement of BLDS probes/sensors, and pressure drag can be used to ensure sufficient adhesive is used to install BLDS instrumentation. The Mach number for all CFD cases was 0.12 and the Reynolds number based on excrescence height varied from 4 x 10 …

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Dice Testing With The Running Chi-Square Distribution, Warren Campbell, Hunter Wimsatt Jul 2022

Dice Testing With The Running Chi-Square Distribution, Warren Campbell, Hunter Wimsatt

SEAS Faculty Publications

Dice are not fair. Producing a geometrically precise, uniform die is not possible. Casino dice come as close as possible to perfectly random dice because they are machined to an accuracy of a few ten-thousandths of an inch and the putty used for the pips (dots) is the same density as the plastic die body. Polyhedral dice used in games like Dungeons and Dragons are far more difficult to manufacture to high tolerances. Some dice are fairer than others. Since 20-sided dice (D20s) are very difficult to manufacture precisely, they were the focus of this study. The running chi-square distribution …

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Microstructure Dependence Of The Thermal Radiative Properties In Yttria-Stabilized Zirconia Thermal Barrier Coatings, Yao Wang Jul 2022

Microstructure Dependence Of The Thermal Radiative Properties In Yttria-Stabilized Zirconia Thermal Barrier Coatings, Yao Wang

Theses and Dissertations

Thermal barrier coatings (TBCs) based on the yttria-stabilized zirconium dioxide (YSZ) are widely used in gas turbines. With increasing gas turbine combustion temperature to improve the thermal efficiency, the radiative heat transfer properties of YSZ coatings become important. Currently there is no clear understanding the relationship between the coating microstructure and the radiative properties. In this study, a hybrid computational approach is developed to invert the radiative properties form the spectral measurement. To investigate the relationship between the radiative properties and microstructure, a predictive model of the scattering coefficient is developed based on the pore size distribution obtained from SEM …

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Internal Energy Balance And Aerodynamic Heating Predictions For Hypersonic Turbulent Boundary Layers, Matthew Barone, Gary L. Nicholson, Lian Duan Jul 2022

Internal Energy Balance And Aerodynamic Heating Predictions For Hypersonic Turbulent Boundary Layers, Matthew Barone, Gary L. Nicholson, Lian Duan

Mechanical and Aerospace Engineering Faculty Research & Creative Works

The elemental equation governing heat transfer in aerodynamic flows is the internal energy equation. For a boundary layer flow, a double integration of the Reynolds-averaged form of this equation provides an expression of the wall heat flux in terms of the integrated effects, over the boundary layer, of various physical processes: turbulent dissipation, mean dissipation, turbulent heat flux, etc. Recently available direct numerical simulation data for a Mach 11 cold-wall turbulent boundary layer allows a comparison of the exact contributions of these terms in the energy equation to the wall heat flux with their counterparts modeled in the Reynolds-averaged Navier-Stokes …

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Molecular Arrangement And Fringe Identification And Analysis From Molecular Dynamics (Mafia-Md): A Tool For Analyzing The Molecular Structures Formed During Reactive Molecular Dynamics Simulation Of Hydrocarbons, Khaled Mosharraf Mosharraf Mukut, Somesh Roy, Eirini Goudeli Jul 2022

Molecular Arrangement And Fringe Identification And Analysis From Molecular Dynamics (Mafia-Md): A Tool For Analyzing The Molecular Structures Formed During Reactive Molecular Dynamics Simulation Of Hydrocarbons, Khaled Mosharraf Mosharraf Mukut, Somesh Roy, Eirini Goudeli

Mechanical Engineering Faculty Research and Publications

Reactive molecular dynamics (RMD) simulations are becoming popular, with the recent developments in high-performance and efficient computing architecture, for investigating fundamental physico-chemical behaviors of reacting species. Due to the complexity of hydrocarbon systems, characterization of molecules formed during RMD simulations of hydrocarbons can be very challenging for simulations involving a large number of molecules. The novel post-processing utility “MAFIA-MD” – an acronym for “Molecular Arrangement and Fringe Identification and Analysis from Molecular Dynamics” – presented in this manuscript can analyze and perform molecular characterization of a large number of RMD trajectory files (.XYZ files) simultaneously. The utility will be useful …

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Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center Jul 2022

Carbon Capture, Utilization, And Storage, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about carbon capture, utilization, and storage (CCUS) and the Energy & Environmental Research Center’s CCUS capabilities. Includes information on the Plains CO2 Reduction (PCOR) Partnership initiative, Brine Extraction and Storage Test (BEST), Carbon Storage Assurance Facility Enterprise (CarbonSAFE), Red Trail Energy Carbon Capture and Storage, a feed study at Coal Creek Station, Bell Creek and Cedar Creek anticline projects, and Partnership for CO2 Capture (PCO2C). [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

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Ti–6al–4v Alloy Deposition Characteristics At Electrode-Negative Polarity In The Cold Metal Transfer–Gas Metal Arc Process, Tae Hyun Lee, Dong Hyuck Kam, Je Hoon Oh, Cheolhee Kim Jul 2022

Ti–6al–4v Alloy Deposition Characteristics At Electrode-Negative Polarity In The Cold Metal Transfer–Gas Metal Arc Process, Tae Hyun Lee, Dong Hyuck Kam, Je Hoon Oh, Cheolhee Kim

Mechanical and Materials Engineering Faculty Publications and Presentations

Although wire arc additive manufacturing (WAAM) of Ti alloys using gas metal arc yields a high deposition rate, cathode spots exhibit unstable behavior. In this study, the cold-metal-transfer process and an electrode-negative (EN) polarity were used in the WAAM process of the Ti–6Al–4V alloy. High-speed imaging was performed to investigate the mechanisms to stabilize cathode plasma jets, arc plasma, and molten metal transfer in the EN polarity. Arc plasma and cathode jets had the same direction, and sound cathode jets were shrouded by arc plasma in the EN mode. The metal transfer was also stabilized by balanced plasma formation under …

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Error Estimate Of A Decoupled Numerical Scheme For The Cahn-Hilliard-Stokes-Darcy System, Wenbin Chen, Shufen Wang, Yichao Zhang, Daozhi Han, Cheng Wang, Xiaoming Wang Jul 2022

Error Estimate Of A Decoupled Numerical Scheme For The Cahn-Hilliard-Stokes-Darcy System, Wenbin Chen, Shufen Wang, Yichao Zhang, Daozhi Han, Cheng Wang, Xiaoming Wang

Mathematics and Statistics Faculty Research & Creative Works

We analyze a fully discrete finite element numerical scheme for the Cahn-Hilliard-Stokes-Darcy system that models two-phase flows in coupled free flow and porous media. To avoid a well-known difficulty associated with the coupling between the Cahn-Hilliard equation and the fluid motion, we make use of the operator-splitting in the numerical scheme, so that these two solvers are decoupled, which in turn would greatly improve the computational efficiency. The unique solvability and the energy stability have been proved in Chen et al. (2017, Uniquely solvable and energy stable decoupled numerical schemes for the Cahn-Hilliard-Stokes-Darcy system for two-phase flows in karstic geometry. …

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Exploring Passive Flow Control Techniques Applied To A Supersonic Multistream Rectangular Nozzle, Emma Dawn Gist Jul 2022

Exploring Passive Flow Control Techniques Applied To A Supersonic Multistream Rectangular Nozzle, Emma Dawn Gist

Dissertations - ALL

Passive control techniques are applied experimentally to examine different aspects of a supersonic multistream rectangular nozzle representing a modern airframe-integrated variable cycle engine. The flow is comprised of a core stream (M = 1.6) and bypass (M = 1.0) that merge behind a splitter plate and exit through a Single Expansion Ramp Nozzle (SERN) onto an aft-deck. Previous efforts for the nominal nozzle configuration have shown that an instability initiated at the splitter plate trailing edge (SPTE) influences the effectiveness of the third stream as a barrier for the aft-deck and persists through the entire do- main due to its …

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Processing Time, Temperature, And Initial Chemical Composition Prediction From Materials Microstructure By Deep Network For Multiple Inputs And Fused Data, Amir Abbas Kazemzadeh Farizhandi, Mahmood Mamivand Jul 2022

Processing Time, Temperature, And Initial Chemical Composition Prediction From Materials Microstructure By Deep Network For Multiple Inputs And Fused Data, Amir Abbas Kazemzadeh Farizhandi, Mahmood Mamivand

Mechanical and Biomedical Engineering Faculty Publications and Presentations

Prediction of the chemical composition and processing history from microstructure morphology can help in material inverse design. In this work, we propose a fused-data deep learning framework that can predict the processing history of a microstructure. We used the Fe-Cr-Co alloys as a model material. The developed framework is able to predict the heat treatment time, temperature, and initial chemical compositions by reading the morphology of Fe distribution and its concentration. The results show that the trained deep neural network has the highest accuracy for chemistry and then time and temperature. We identified two scenarios for inaccurate predictions; 1) There …

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Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca Jul 2022

Predicting The Remaining Service Life Of Railroad Bearings: Leveraging Machine Learning And Onboard Sensor Data, Leonel Villafranca

Theses and Dissertations

By continuously monitoring train bearing health in terms of temperature and vibration levels of bearings tested in a laboratory setting, statistical regression models have been developed to establish relationships between the sensor-acquired bearing health data with several explanatory factors that potentially influence the bearing deterioration. Despite their merits, statistical models fall short of reliable prediction accuracy levels since they entail restrictive assumptions, such as a priori known functional relationship between the response and input variables. A data-driven machine learning algorithm is presented, which can unravel the nonlinear deterioration model purely based on the bearing health data, even when the structure …

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Large Area Projection Sintering Of Semicrystalline Polymers And Part Analysis Of The Printed Specimens, Taranjot Kaur Jul 2022

Large Area Projection Sintering Of Semicrystalline Polymers And Part Analysis Of The Printed Specimens, Taranjot Kaur

USF Tampa Graduate Theses and Dissertations

As the requirements posed to products have increased in recent years. The trend towards individualized serial products steps up the need for respective manufacturing techniques to be more and more flexible. Conventional techniques of serial production, such as injection molding, are unable to fully meet the requirements of this trend. Additive manufacturing techniques generate components directly from a CAD data set while requiring no specific mold, producing minimal waste, and reaching satisfactory geometric accuracy. This is how, as opposed to conventional techniques, they comply with these increased demands to processing technology. Over the last two decades, the research community has …

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Hybrid Theory-Machine Learning Methods For The Prediction Of Afp Layup Quality, Christopher M. Sacco Jul 2022

Hybrid Theory-Machine Learning Methods For The Prediction Of Afp Layup Quality, Christopher M. Sacco

Theses and Dissertations

The advanced manufacturing capabilities provided through the automated fiber placement (AFP) system has allowed for faster layup time and more consistent production across a number of different geometries. This contributes to the modern production of large composite structures and the widespread adaptation of composites in industry in general and aerospace in particular. However, the automation introduced in this process increases the difficulty of quality assurance efforts. Industry available tools for predicting layup quality are either limited in scope, or have extremely high computational overhead. With the advent of automated inspection systems, direct capture of semantic inspection data, and therefore complete …

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