Mechanical Engineering Commons^™

Real-Time Length Sensing Of Braided Pneumatic Actuator Using Ir Time-Of-Flight Sensor, Luon B. Chung

Dissertations and Theses

Braided Pneumatic Actuators (BPAs) are used widely in robotics as artificial muscles because of their similar characteristics to biological muscles. When a BPA is pressurized, it expands in the radial direction and contracts in the longitudinal direction. The contraction generates a pulling force that is dependent on the input pressure and BPA length. Biological muscle also behaves in the same way where a pulling force is generated on a contraction. To control BPAs on a robot, the real-time pressure and length measurements are necessary. In this dissertation, I present a new method to measure length of BPAs in real-time using …

Structural Configuration Of Amorphous Silica Surface With Different Terminating Groups Using Classical And Ab Initio Molecular Dynamics, Md Azharul Islam

Student Theses and Dissertations

Silica has numerous applications across various sectors of technology, including concrete production, glass production, food additives, and semiconductor technology. The surface interaction properties of amorphous silica are crucial, yet many aspects of these interactions, particularly with passivating groups, are still not fully understood because amorphous silica’s nature is non-periodic. In this study, computational simulations are used to understand the bonding mechanism and atomic structure of the amorphous silica surfaces with different passivating groups. Amorphous silica surfaces are generated by melt-quench dynamics using classical molecular dynamics (MD). Then, subdomains of these surfaces containing an undercoordinated surface atom are selected for ab …

Enhancing Human Key Point Identification: A Comparative Study Of High-Resolution Vicon Dataset And Coco Dataset Using Bpnet, Bibash Lama

Masters Theses

Accurately identifying human key points is crucial for various applications, including activity recognition, pose estimation, and gait analysis. This study presents a high-resolution dataset created using the VICON motion capture system and three differently oriented 2D cameras, that can be used to train different neural networks for estimating the 2D key joint positions of the person from the 2D images or videos. The participants in the study included 25 healthy adults (17 males and 8 females) performing normal gait movements for about 2 to 3 seconds. The VICON system captured 3D ground truth data, while the three 2D cameras collected …

Hierarchical Based Classifcation Method Based On Fusion Ofgaussian Map Descriptors Foralzheimer Diagnosis Using T1‑Weighted Magnetic Resonance Imaging, Nourhan Zayed, Shereen E. Morsy, Inas A. Yassine

Mechanical Engineering

Alzheimer’s disease (AD) is considered one of the most spouting elderly diseases. In 2015, AD is reported the US’s sixth cause of death. Substantially, non-invasive imaging is widely employed to provide biomarkers supporting AD screening, diagnosis, and progression. In this study, Gaussian descriptors-based features are proposed to be efcient new biomarkers using Magnetic Resonance Imaging (MRI) T1-weighted images to diferentiate between Alzheimer’s disease (AD), Mild Cognitive Impairment (MCI), and Normal controls (NC). Several Gaussian map-based features are extracted such as Gaussian shape operator, Gaussian curvature, and mean curvature. The aforementioned features are then introduced to the Support Vector Machine (SVM). …

A Multi-Aerial Vehicle Platform For Testing Collaborative Mobility Formation Controllers, Matthew Snellgrove

LSU Master's Theses

Multi-agent systems have potential applications in a multitude of fields due to their ability to perform complex tasks with a high degree of robustness. Decentralized systems are multi-agent systems where sensing, control, and communication responsibilities are distributed amongst the agents giving this scheme a particularly high potential for robustness, adaptability, and complexity; however, this comes with its own list of challenges. Formation control is a topic in multi-agent systems that aims to have the agents moving as a virtual rigid body through space. In the literature, there have been successful implementation of formation control algorithms on robot agents in both …

Extreme Cooling Via Sweeping Gas Membrane Distillation, David M. Warsinger

School of Mechanical Engineering Faculty Publications

Thermal desalination processes like membrane distillation (MD) aim to have rapid evaporation rates to provide large quantities of fresh water. These processes, which resemble counterflow-heat exchangers with membranes in the middle, conventionally seek to maximize vapor mass transfer while minimizing all other modes of heat transfer as “thermal losses.” However, we can reverse this fundamental design need to make an exceptionally high throughput heat dissipation device. By using thin thermally conductive membranes and extremely rapid air flow rates, membrane heat exchangers inspired by MD can dissipate heat several times faster than conventional air-cooled heat exchangers. We demonstrate this new approach …

Modeling Of Heat And Mass Transfer In Flat Heat Pipes, Salar Saadatian

LSU Doctoral Dissertations

Phase-change phenomenon is ubiquitous in nature and widely utilized in thermal management of computer chips. Flat heat pipes have been extensively used in thermal management of microelectronic devices. However, existing research mainly concentrates on developing numerical models and lacks a systematic analytical approach to elucidate the working mechanism of flat heat pipes. We consider a horizontal flat heat pipe with an idealized porous wick. The pores in the wick are straight circular capillaries running along and across the wick and are filled with a liquid. The rest of the pipe is filled with its vapor. The mass evaporative rate at …

On The Design And Power Output Response Of Hydraulic Wind Turbines, Helber Antonio Esquivel-Puentes, Andrea Vacca, Venkatesh Pulletikurthi, Ali Doosttalab, Jose Garcia-Bravo, David M. Warsinger, Leonardo P. Chamorro, Luciano Castillo

School of Mechanical Engineering Faculty Publications

Standard horizontal axis wind turbines typically use gearboxes for large-scale applications and direct coupling for small-scale designs to connect the rotor to the generator. However, gearboxes pose challenges due to their weight, cost, and exposure to dynamic loads and vibrations within the nacelle. A promising alternative is replacing mechanical transmission with a hydrostatic counterpart, offering advantages such as reduced nacelle mass, generator placement at the tower base, and elimination of the gearbox. It can potentially lead to cost savings of up to 20% in the levelized cost of electricity for offshore wind turbines. This study compares regulated hydrostatic transmission with …

Explainable Ai For Tool Wear Prediction In Turning, Saleh Valizadeh Sotubadi, Rui Liu, Vinh Nguyen

Michigan Tech Publications

This research aims develop an Explainable Artificial Intelligence (XAI) framework to facilitate human-understandable solutions for tool wear prediction during turning. A random forest algorithm was used as the supervised Machine Learning (ML) classifier for training and binary classification using acceleration, acoustics, temperature, and spindle speed during the orthogonal tube turning process as input features. The ML classifier was used to predict the condition of the tool after the cutting process, which was determined in a binary class form indicating if the cutting tool was available or failed. After the training process, the Shapley criterion was used to explain the predictions …

Experimental Analysis On Effects Of Inclination And Direction On Supercritical Carbon Dioxide Heat Transfer For Internal Pipe Flow, Emmanuel Gabriel-Ohanu

Electronic Theses and Dissertations, 2020-2023

Supercritical carbon dioxide (sCO2) can be utilized as a working or heat transfer fluid in various thermal systems with applications in large-scale power cycles; portable power production units, coolant systems and devices. However, there are no sufficient methods and equations of heat transfer coefficient correlations, and in addition insufficient research studies about the mechanisms controlling heat transfer processes for sCO2. This study is motivated by the need to understand the intricate properties of sCO2 heat transfer and fluid dynamics with an emphasis on flow direction and inclination effects. This paper presents the study on effects of gravity, buoyancy on sCO2 …

Power Packet Networks For Wave Energy Converter Arrays, David G. Wilson, Raymond H. Byrne, Steven F. Glover, Tu Anh Nguyen, Rush Robinett, Wayne Weaver, Et. Al

Michigan Tech Patents

One of the biggest challenges for all renewable energy sources (RES) is that they are variable power generators which will require reactive power or energy storage systems (ESS) to provide reliable power quality (ideally power factor of one) at the power grid generation side. The present invention is directed to a power packet network (PPN) for integrating wave energy converter (WEC) arrays into microgrids. Specifically, an array of WECs can be physically positioned such that the incoming regular waves will produce an output emulating an N-phase AC system such that the PPN output power is constant. ESS requirements are thereby …

Stochastic Modeling Of Physical Drag Coefficient – Its Impact On Orbit Prediction And Space Traffic Management, Smriti Nandan Paul, Phillip Logan Sheridan, Richard J. Licata, Piyush M. Mehta

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Ambitious satellite constellation projects by commercial entities and the ease of access to space in recent times have led to a dramatic proliferation of low-Earth space traffic. It jeopardizes space safety and long-term sustainability, necessitating better space domain awareness (SDA). Correct modeling of uncertainties in force models and orbital states, among other things, is an essential part of SDA. For objects in the low-Earth orbit (LEO) region, the uncertainty in the orbital dynamics mainly emanate from limited knowledge of the atmospheric drag-related parameters and variables. In this paper, which extends the work by Paul et al. (2021), we develop a …

Prediction Of Transient Hydrogen Flow Of Proton Exchange Membrane Electrolyzer Using Artificial Neural Network, Mohammad Biswas, Tabbi Wilberforce, Mohammad A. Biswas

Mechanical Engineering Faculty Publications and Presentations

A proton exchange membrane (PEM) electrolyzer is fed with water and powered by electric power to electrochemically produce hydrogen at low operating temperatures and emits oxygen as a by-product. Due to the complex nature of the performance of PEM electrolyzers, the application of an artificial neural network (ANN) is capable of predicting its dynamic characteristics. A handful of studies have examined and explored ANN in the prediction of the transient characteristics of PEM electrolyzers. This research explores the estimation of the transient behavior of a PEM electrolyzer stack under various operational conditions. Input variables in this study include stack current, …

Heat And Mass Transfer Modeling Of High-Temperature Moving-Bed Thermochemical Reactors, David Korba

Theses and Dissertations

With the global deployment of renewable energy generation at record rates, clean energy is steadily becoming competitive with its fossil-fuel counterparts. However, further expansion is limited by the inherent intermittency of renewable energy sources (solar, wind, wave, etc.), which typically do not match with daily and seasonal variations of global (and local) energy demand. Thermochemical energy storage (TCES) has demonstrated strong potential in being a technological pathway to provide on-demand process heat and handle the intrinsic variations in renewable energy generation and energy demand. TCES works on the premise of excess renewable heat driving an endothermic reduction reaction, in which …

Multi-Objective Design Optimization Of Two Configurations Of Ventricular Shunts For Hydrocephalus, Will Kirkpatrick

Theses and Dissertations

Hydrocephalus is developed when the flow of cerebrospinal fluid is obstructed in the ventricles and a pressure build-up is generated within the brain. Ventricular shunts are used to remove excess fluid from the brain, but these shunts have a common problem of failure due to the shunt being obstructed by the build-up of astrocytes. To address this, two sets of 27 designs of ventricular shunts were identified and analyzed with parameters that could potentially reduce obstruction risks. The performance of these designs was examined using fluid simulations on these two sets of 27 designs. One set explored close-tipped shunt designs, …

Nanoscale Modeling Of Membrane Systems Under Mechanical Deformation In Traumatic Brain Injury Using Molecular Dynamics, Anh Thi Ngoc Vo

Theses and Dissertations

Neuronal membrane disruption and mechanoporation are nanoscale damage mechanisms that critically affect brain cell viability during traumatic brain injury (TBI). These nanoscale cellular impairments are elusive in experiments and necessitate in silico approaches such as molecular dynamics (MD) simulations. Implementing MD, this research aims to investigate the effects of different key factors related to membrane deformation and damage, including force field resolutions, lipid compositions, and loading conditions.

To examine the impact of force field resolution, MD deformation simulations were conducted on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine (POPC) lipid bilayer membranes, using all-atom (AA), united-atom (UA), and coarse-grained Martini (CG-M) force fields. The mechanical responses …

Effects Of Machining Parameters Of C45 Steel Applying Vegetable Lubricant With Minimum Quantity Cooling Lubrication (Mqcl), Mayur A. Makhesana, Prashant J. Bagga, Kaushik M. Patel, Jaime Taha-Tijerina

Informatics and Engineering Systems Faculty Publications

One of the most significant performance indicators for measuring the machinability of materials is tool wear and surface roughness. Choosing the best combination of cutting parameters can help reduce production costs, which is what the manufacturing industry is interested in. At the same time, industries are always looking for an alternative to conventional flood cooling since its use creates an environmental burden and health concerns for the operators. Therefore, vegetable oil-based minimum quantity cooling lubrication (MQCL) is considered a cutting environment. Sunflower oil is utilized as base fluid in MQCL and applied to the cutting zone through a nozzle. The …

Influence Of Forming Forces On Torsional, Tensile, And Compressive Deformation Of Paperboard Packages, Arvo Niini, Panu Tanninen, Juha Varis, Ville Leminen

Journal of Applied Packaging Research

Paperboard packages were tested mechanically to investigate influence of forming forces on torsional, tensile, and compressive deformation. The packages were paperboard trays which were press formed with different pressing forces and blank holder forces. Deformation of the trays was observed with torsion, compression, and tensile tests. A statistical analysis of test results was conducted to derive optimal forming forces. Increased pressing force yielded desirable deformation characteristics with the trays. Blank holder force had largest impact on the compressive deformation. Interaction of the pressing force and the blank holder force influenced the torsional and the compressive deformation. The optimal forming forces …

A Robust Model Reduction For The Optimal Boundary Feedback Stabilization Of Magnetizable Piezoelectric Beams, Md Rafi As Sadeq Ibn Emran

Masters Theses & Specialist Projects

The one-dimensional Partial Differential Equation (PDE) model of the wave equation, which describes wave dynamics of a wide-range of controlled mechanical systems, with a state feedback controller at its boundary is known to have exponentially stable solutions. Moreover, it is also reported that the several model reductions of the wave equation by the standard Finite Differences and Finite Elements approximations suffer from the lack of exponential stability (and exact observability without a state feedback controller) uniformly as the discretization parameter tends to zero. This is due to the loss of a uniform gap among the high-frequency eigenvalues as the discretization …

Fatigue And Fracture Of Electron Beam Melting Ti-6al-4v, William A. Grell

Electronic Theses and Dissertations

For applications in the aerospace field, selection of materials for a given design requires an understanding of critical properties, like fatigue and fracture, in addition to static mechanical and physical properties. With the ongoing advancements in metallic additive manufacturing techniques and the interest in applying the process to aerospace applications, there is a clear need to fully characterize properties. Arguably, the most attractive alloy for applications in aerospace is the Ti-6Al-4V alloy. The current dissertation examines the mechanical properties of the alloy, made by the Electron Beam Melting (EBM) Powder Bed Fusion (PBF) method. As illustrated in this work, the …

Hemodynamic Assessment Of Y-Incision Aortic Root Enlargement Using Computational Simulations, Astitwa Ghimire

Electronic Theses and Dissertations

The Yang procedure is a new aortic root enlargement technique used to enlarge the aortic annulus by multiple valve sizes. The procedure prevents patient prosthesis mismatch and establishes a viable platform for future valve-in-valve implantation. This study used the Yang procedure to investigate the hemodynamics in the aortic root and bioprosthetic valve regions after aortic root enlargement. Results indicate the velocity magnitude at the sinus regions of a patient who underwent the Yang procedure was slower, indicating risks of flow stasis and thrombosis. Simulation results denote computational models can be created for optimization of surgical procedures.

Machine Learning Based Average Pressure Coefficient Prediction For Isolated High-Rise Buildings, Shiva Sai Reddy Marapakala

ETD Archive

In structural design, the distribution of wind-induced pressure exerted on structures is crucial. The pressure distribution for a particular building is often determined by scale model tests in boundary layer wind tunnels (BLWTs). For all combinations of interesting building shapes and wind factors, experiments with BLWTs must be done. Resource or physical testing restrictions may limit the acquisition of needed data because this procedure might be time-and resource-intensive. Finding a trustworthy method to cyber-enhance data-collecting operations in BLWTs is therefore sought.

This research analyzes how machine learning approaches may improve traditional BLWT modeling to increase the information obtained from tests …

High Magnification Surface Topography Based Digital Image Correlation (Dic) For Identifying Damage Accumulation And Crack Growth In Polycrystalline Nickel, Arash Valiollahi

Mechanical and Aerospace Engineering Dissertations - Archive

Damage index parameters that have been formulated to identify damage localization in plastically deformed materials typically require all six stress or strain components. Recently, simulations through Crystal Plasticity Finite Element Method (CPFEM) have been widely used to extract damage initiation parameters. However, these models are rarely verified due to the challenges in measuring the out-of-plane deformation/strain experimentally. A damage index combining the effective plastic strain and surface roughness change is investigated for identifying damage accumulation sites and predicting crack propagation path in polycrystalline pure Nickel. A novel Digital Image Correlation (DIC) technique is developed to measure both in-plane and out-of-plane …

Investigation Of Thermal Performance Enhancement And Thermo-Mechanical Assessment Of Ite Using Single-Phase Immersion Cooling Technology, Pratik Bansode

Mechanical and Aerospace Engineering Dissertations - Archive

The use of air-cooling as a thermal management technique in data centers has consistently maintained its importance, however its efficacy is limited to CPUs with lower power requirements. The expenses and energy use related to the air circulation process for high-power density racks are deemed excessively costly. The limits of air cooling have aroused concerns owing to its low specific heat capacity and poor thermal conductivity, which result in reduced effectiveness. Consequently, a substantial discourse has emerged about alternate and effective cooling methods that provide supplementary advantages, such as the recuperation of waste heat. In light of the limitations associated …

Optimal Aggressive Constrained Trajectory Synthesis And Control For Multi-Copters, Tsung-Liang Liu

Mechanical and Aerospace Engineering Dissertations - Archive

Multi-copters have become increasingly popular in recent years due to their availability, mobility, agility, and flexibility. They serve as excellent platforms for control experiments and various applications. Their characteristics also make them an attractive choice for high-speed aerial navigation in complex environments. Numerous studies have been conducted on aggressive trajectory generation and maneuver tracking. However, the level of aggressiveness achievable depends on the optimality of the trajectory plan and the dynamic capabilities of the vehicle. It would be valuable if one can generate a trajectory that fully utilizes the dynamic capabilities of the multi-copter while accommodating specific maneuvers at predetermined …

Analyzing The Thermomechanical Performance Of Tg400g Material Substrate Core Under Immersion Cooling, Venkateswar Vishnu Tirupati Venkatachal

Mechanical and Aerospace Engineering Theses - Archive

The relentless surge in demand for seamless information exchange through consumer electronics, driven by the indispensable role of the Internet, has given rise to an unprecedented need for data centres. Yet, the energy consumption of conventional data centres, where a significant one-third of energy usage is attributed solely to cooling, has triggered an urgent quest for energy-efficient solutions. Immersion cooling technology appears as a promising contender due to its exceptional prowess in managing thermal energy. However, its potential impact on the reliability of IT equipment needs a more profound exploration before widespread adoption can be realized. This study embarks on …

Electromagnetic Simulations Of The Lansce Chopper Structure, Yusuf Sahin

Electrical and Computer Engineering ETDs

Particle accelerators are important for basic research as well as in applications such as ion implantation and cancer therapy. One important accelerator is the Los Alamos Neutron Science Center (LANSCE) located at Los Alamos National Laboratory (LANL) that primarily produces neutrons for research. The beam chopper simulation described here is a study to provide better modeling of this subsystem of LANSCE. A chopper is a device in which particles are intermittently sliced and directed to a target and/or experiment. The simulations in this thesis are used to analyze the correct operating parameters of the chopper. A good chopper model can …

Performance And Emissions Study Of N+3 And N+4 Engine Models With Several Fuel Types Using Npss, Abel Solomon

McKelvey School of Engineering Graduate Student Theses & Dissertations

The aviation industry is known to be one of the major contributors to greenhouse gases accounting for 4.9% of the global greenhouse emissions. With the ever-increasing threat of climate change to the overall survival of the planet, the exploration of new technologies and alternative energy sources that minimize greenhouse gas emissions are of paramount importance. In this regard, the development of propulsion systems well suited for the performance and emissions requirements of future commercial aircraft plays a crucial role. This thesis investigates N+3 and N+4 technology-level propulsion systems that are proposed by NASA as possible propulsion systems for advanced single-aisle …

Vibration Fatigue Of Leaded Solder Joint Interconnects For Pcb Electronics, John Crowder

All Theses

With the increasing prevalence of electronic equipment worldwide, there is also a decrease in the size of the components on their printed circuit boards (PCBs), leading to an increase in the density of these components. A significant amount of failure in electronic equipment is vibration fatigue of solder joints and their attachments. However, the complexity of these PCBs and their components has made finite element modeling (FEM) more complex, adding considerable time to create and analyze a model.

This paper aims to provide a literature review for the vibration fatigue of leaded solder components, create a test setup, and validate …

Life Cycle Energy Assesment Of Advanced Fiber Reinforced Composite Design And Manufacturing Methodologies, Urjit Lad

All Theses

Automotive industry at large is focused on vehicle light-weighting since a 6%-8% increase in fuel efficiency can be achieved with a 10% reduction in vehicle weight [1]. With the growing demand for cost-effective and sustainable light weighting of automobile structures, interest has increased in the application of fiber reinforced plastic (FRP) composites for use in the Body-in-White (BiW), which can account for up to 40% of the total vehicle weight. Traditional FRP composite manufacturing processes like vacuum assisted resin transfer molding, autoclave consolidation or use of automated fiber placement have been successfully used for marine and aerospace applications. However, these …