Mechanical Engineering Commons^™

Optimal Energy Management For Off-Grid Hybrid Renewable Energy Systems, Owdean M. Suwi

Tanzania Journal of Engineering and Technology (TJET)

A photovoltaic (PV)/wind/battery/Generator-Set hybrid power system's energy dispatch is discussed in this research, along with the ideal solution. The optimization model enables the hybrid power system's generating devices to share power appropriately. The main goals are to minimize fuel consumption and costs and maximize the usage of Renewable Energy Sources (RES). The proposed simulation plan succeeds in lowering fuel costs because the diesel generator only kicks on at night and in the early morning when the energy from RES is insufficient to supply the load. The load is supplied with power, and the battery is charged throughout the day, when …

Investigation Of Electrically Isolated Capacitive Sensing Skins On Concrete To Reduce Structure/Sensor Capacitive Coupling, Emmanuel Ogunniyi, Alexander Vareen, Austin Downey, Simon Laflamme, Jian Li, Caroline Bennett, William Collins, Hongki Jo, Alexander Henderson, Paul Ziehl

Faculty Publications

Damage to bridges can result in partial or complete structural failures, with fatal consequences. Cracks develop in concrete infrastructure from fatigue loading, vibrations, corrosion, or unforeseen structural displacement. Effective long-term monitoring of civil infrastructure can reduce the risk of structural failures and potentially reduce the cost and frequency of inspections. However, deploying structural health monitoring technologies for crack detection on bridges is expensive, especially long-term, due to the density of sensors required to detect, localize, and quantify cracks. Previous research on soft elastomeric capacitors (SECs) has shown their viability for low-cost monitoring of cracks in transportation infrastructure. However, when deployed …

Creativity, Craftsmanship, And Connection: Large-Format Sculpture Design, Jacqueline L. Puga, Gordon Hoople

The Transdisciplinary STEAM+ Journal

Artistry is a concept that is not usually explored in engineering yet is an invaluable skill that touches everything from product design to systems thinking. This past summer I developed conceptual designs for a large format sculpture that required connecting engineering knowledge with artistic vision. The initial phase required constant inspiration and creativity. The first step was to look at previous sculptures showcased throughout the world, such as at venues like “Burning Man,” to understand the possibilities or limitations of the space provided. Sketching varied and numerous ideas was essential in our design process. Next, we took our favorite ideas …

Hemodynamic Investigations In Intracranial Aneurysms: A Commentary, Hang Yi, Mark Johnson, Luke Bramlage, Zifeng Yang, Bryan Ludwig

Mechanical and Materials Engineering Faculty Publications

Intracranial aneurysms (IAs) are abnormal bulges in a blood vessel in the brain that have a potential to rupture and even causing a stroke, which can lead to lasting brain damage, long-term disability, or even loss of life. It has been widely acknowledged that hemodynamic factors, e.g., instantaneous wall shear stress, time-averaged wall shear stress, wall shear stress gradient, gradient oscillatory number, oscillatory shear index, pulsatile blood flow waveform (flow rate magnitude and shape, physical flow period), relative residence time/turnover time, blood pressure, and vortex (i.e., size, location, and numbers), have a close relationship with the pathobiology (i.e., initiation, growth, …

Boron Nitride Nanotubes: Force Field Parameterization, Epoxy Interactions, And Comparison With Carbon Nanotubes For High-Performance Composite Materials, Swapnil S. Bamane, Michael B. Jakubinek, Krishan Kanhaiya, Behnam Ashrafi, Hendrik Heinz, Gregory Odegard

Michigan Tech Publications, Part 1

Boron nitride nanotubes (BNNTs) are a very promising reinforcement for future high-performance composites because of their excellent thermo-mechanical properties. To take full advantage of BNNTs in composite materials, it is necessary to have a comprehensive understanding of the wetting characteristics of various high-performance resins. Molecular dynamics (MD) simulations provide an accurate and efficient approach to establish the contact angle values of engineering polymers on reinforcement surfaces, which offers a measure for the interaction between the polymer and reinforcement. In this research, MD simulations and experiments are used to determine the wettability of various epoxy systems on BNNT surfaces. The reactive …

Automatic Dispersion, Defect, Curing, And Thermal Characteristics Determination Of Polymer Composites Using Micro-Scale Infrared Thermography And Machine Learning Algorithm, Md Ashiqur Rahman, Mirza Masfiqur Rahman, Ali Ashraf

Mechanical Engineering Faculty Publications

Infrared thermography is a non-destructive technique that can be exploited in many fields including polymer composite investigation. Based on emissivity and thermal diffusivity variation; components, defects, and curing state of the composite can be identified. However, manual processing of thermal images that may contain significant artifacts, is prone to erroneous component and property determination. In this study, thermal images of different graphite/graphene-based polymer composites fabricated by hand, planetary, and batch mixing techniques were analyzed through an automatic machine learning model. Filler size, shape, and location can be identified in polymer composites and thus, the dispersion of different samples was quantified …

Biogas Combustion Characteristics In A Concentric Flow Slot Burner: Effects Of Co2 Concentration On Stability And Flame Structure, Maged Kiriakos

Theses and Dissertations

Biogas combustion is affected by the concentration of carbon dioxide. The successful applications of Biogas as a sustainable renewable alternative fuel produced from waste depend on its combustion stability, heat release, and pollution level. The aim of the current study is to apply new combustion technology and study the stability and combustion characteristics of natural gas with different percentages of carbon dioxide from 0 to 40% simulating biogas fuel. The stability characteristics and the temperature profiles of turbulent planar flames at different levels mixture inhomogeneity are investigated and presented in this work. The flames are created in a newly developed …

Simulation Of Natural Tornado Genesis And Evolution From An Initial Instability Profile, Kakkattukuzhy M. Issac

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A likely mechanism for the little-understood tornado genesis is proposed and its numerical implementation is presented. The Burgers-Rott vortex with its axis in the vertical direction is introduced as an instability mechanism, and the flow field then evolves under the influence of the atmospheric pressure, temperature and density variations with altitude. Buoyancy effects are implemented using the Boussinesq model. Results are presented and discussed for a set of conditions including mesh type and size, different turbulence models, and a few different boundary conditions. Post-processed results of the transient simulations including animations contain a wealth of information to help analyze tornado …

Accurate Evaluation Of The Direction-Dependent Mechanical Properties Of Ideal Single Crystals: A Comparative Ab Initio Study, Jaylan Ali Elhalawani

Theses and Dissertations

The mechanical properties of a single crystal or a grain in a polycrystalline material are highly dependent on the direction of the applied load. Key properties of interest are the Young’s modulus and the Poisson ratio in the small strain limit, and the ideal tensile strength in the large strain regime. Prior atomistic computations of these properties interchangeably used two approaches. In one approach the stress-strain response is explicitly calculated via a numerical tensile test experiment. In the second approach the second order single crystal elastic constants are computed via small deformations and then used in analytical equations to derive …

Changes In The Mechanical Performance Of An Ortho-Planar Spring After Aging Tests, Lucas F. L. Santos, Larry L. Howell, Jose J. R. D’Almeida

Faculty Publications

This paper analyzed an ortho-planar spring (OPS) compliant mechanism and evaluated its mechanical performance after hygrothermal and ultraviolet radiation aging tests. The aging analysis performed here addresses the performance of compliant mechanisms after aging processes which can help inform the design of future compliant mechanisms. ASTM D638 tensile test type I samples were also submitted to aging to serve as a comparison for OPS samples. The samples were submitted to three different kinds of aging conditions, namely water immersion, oil immersion, and ultraviolet radiation. In conclusion, tensile samples showed significant statistical changes in Young's modulus and elongation at break, whereas …

Surface Characterization Of Particulate Dust Subjected To Dew-Induced Cementation, Mohamed Adawi

Student Theses and Dissertations

Accumulation of soils and other particulate matter on the front cover glass of solar photovoltaic (PV) modules results in transmission losses that detrimentally affect the power output of PV installations. Cementation reactions occur due to interactions between the dust and the glass surface in the presence of temperature, humidity, and ph. In this study, accelerated soiling and cementation tests on glass coupons were performed using a custom instrumented soiling chamber and several standardized soils (Arizona Test Dust, Aramco Test Dust, and China Test Dust) to assess soil adhesion and cementation behaviors. Water contact angle (WCA) and X-ray photoelectron spectroscopy (XPS) …

Study Of The Graphene Energy Absorbing Layer And The Viscosity Of Sodium Alginate In Laser-Induced- Forward-Transfer (Lift) Bioprinting, Shuqi Zhou, Jianzhi Li, Ben Xu

Manufacturing & Industrial Engineering Faculty Publications

Laser induced forward transfer (LIFT) bioprinting has been viewed as a new and actively developed three-dimensional bioprinting technology due to its high accuracy and good cell viability. The printing quality is highly dependent on the jet formation and its stability in the LIFT bioprinting process. The objective of this study is to investigate the effect of a graphene Energy Absorbing Layer (EAL) and alginate hydrogel (SA) (w.t. 1% and 2%) viscosity on jet generation in the LIFT bioprinting process. Since SA exhibits a shear-thinning behavior, it is a non-Newtonian fluid. The effect of EAL thickness and SA’s viscosity were addressed …

On The Development And Evaluation Of A Framework For Brain-Computer Interface And Vibrotactile Feedback For Human-Robot-Interaction In Virtual Spaces And Robotic Hardware, Sudip Hazra, Shane Whitaker, Panos S. Shiakolas

Mechanical and Aerospace Student Research - Archive

Research in Brain-Computer Interface (BCI) aims to understand human intent with the goal to enhance Human-Robot Interaction (HRI) especially in the field of assistive robotics. The goal of this research is to develop a behavioral sequence based framework to help persons with upper limb disabilities to maintain self-dependence. The framework aims to operate in stages and links multiple functional components to identify human intent and control a robotic arm. The development, operation, and evaluation of the framework and the linked functional components to acquire, process, evaluate, and map BCI signals generated using facial expressions and head movements to predefined actions …

Estimation Of The Response, Power Spectra, And Whirling Patterns Generated From Mud Circulating Along The Annulus During Drilling Procedures: An Alternative Mathematical Representation Via Finite Element Modelling, Eleazar Marquez

Mechanical Engineering Faculty Publications

In this study, an alternative mathematical representation of a drill-string is proposed to provide an alternative assessment on BHA dynamic alterations. Lateral vibrations remain the focal point of drill-string breakdowns given their high frequency characterization and ability to deviate perforation trajectories from the subsurface target. In this paper, the proposed model consists of an anisotropic rotor subjected to distinct RPMs, an axial force, and a bidirectional harmonic excitation with specified amplitude and assorted duration to simulate annulus motion generated from the mud fluid. In this regard, Euler-Bernoulli beam theory was adopted to establish a complete MDOF mathematical expression and thus …

Development Of An Improved Mathematical Representation Which Captures The Nonlinear Dynamic Behavior Of A Drill-String Assembly, Eleazar Marquez

Mechanical Engineering Faculty Publications

In this study, an improved mathematical representation of a drill-string assembly is developed to provide an alternative assessment on vibration irregularities proliferating downhole due to bit-rock interference. Lateral vibrations receive particular attention due to their high frequency content which alter the dynamic response of the drill-string, instigate casing damage, and impede optimal penetration rates. The response of the drill-string is captured by synthesizing compatible stationary bit excitations, via an auto-regressive digital filter, and implementing Monte Carlo simulation, while the power spectral density function is approximated to elucidate the dynamic characteristics during drilling. Formulating adequate physical parameters for the equation of …

A Probabilistic Analysis In Vibration-Assisted Drilling To Measure Dynamic Behavior During Drilling And Understand Risk Factors, Eleazar Marquez, Samuel Garcia

Mechanical Engineering Faculty Publications

In this paper, a mathematical representation is proposed to further understand the dynamic behavior and risk factors associated with vibration-assisted drilling (VAD) technology. The proposed Timoshenko beam model, which characterizes VAD technology, consists of two passive, counter-rotating coaxial rotors operating simultaneously, subjected to a stochastic excitation. In this regard, a finite element technique was incorporated to determine the physical parameters of the governing equation of motion, where the shear and rotary effects, as well as the gyroscopic couples generated perpendicular to the axis of rotation, were accounted for. Further, the relative velocity between the coaxial rotors was accounted in the …

Quadcopter Control Using Single Network Adaptive Critics, Alberto Velazquez, Lei Xu, Tohid Sardarmehni

Mechanical Engineering Faculty Publications

In this paper, optimal tracking control is found for an inputaffine nonlinear quadcopter using Single Network Adaptive Critics (SNAC). The quadcopter dynamics consists of twelve states and four controls. The states are defined using two related reference frames: the earth frame, which describes the position and angles, and the body frame, which describes the linear and angular velocities. The quadcopter has six outputs and four controls, so it is an underactuated nonlinear system. The optimal control for the system is derived by solving a discrete-time recursive Hamilton-Jacobi-Bellman equation using a linear in-parameter neural network. The neural network is trained to …

Non-Destructive Infrared Thermographic Curing Analysis Of Polymer Composites, Md Ashiqur Rahman, Javier Becerril, Dipannita Ghosh, Nazmul Islam, Ali Ashraf

Mechanical Engineering Faculty Publications

Infrared (IR) thermography is a non-contact method of measuring temperature that analyzes the infrared radiation emitted by an object. Properties of polymer composites are heavily influenced by the filler material, filler size, and filler dispersion, and thus thermographic analysis can be a useful tool to determine the curing and filler dispersion. In this study, we investigated the curing mechanisms of polymer composites at the microscale by capturing real-time temperature using an IR Thermal Camera. Silicone polymers with fillers of Graphene, Graphite powder, Graphite flake, and Molybdenum disulfide (MoS₂) were subsequently poured into a customized 3D printed mold for …

Sagittal Plane Dynamic Model Using Tibiofemoral Articular Geometric Center And Experimental Tibiofemoral Center Of Rotation To Predict Joint Forces During Knee Extension Exercise, Jose Mario Salinas, Dumitru I. Caruntu

Mechanical Engineering Faculty Publications

A 2-dimensional anatomical dynamic model of the patellofemoral joint was developed for investigating the forces that contribute to patellar motion during the knee extension exercise. Sagittal bone profiles were aligned to kinematic experimental data to simulate bone motion. Kinematic experimental data was collected using VICON motion analysis system. Marker coordinate data was used to set body-fixed coordinate systems on femur and tibia. These body-fixed coordinate systems were used to drive the femur and tibia geometric profiles during the knee extension exercise. Kinematic experimental data was used to calculate the relative instant center of rotation of markers on tibia with respect …

Session 11: Can Machine Learning Predict Particle Deposition At Specific Intranasal Regions Based On Computational Fluid Dynamics Inputs/Outputs And Nasal Geometry Measurements?, Mohammad Mehedi Hasan Akash, Zachary Silfen, Diane Joseph-Mccarthy, Arijit Chakravarty, Saikat Basu

SDSU Data Science Symposium

Along with machine learning modeling, numerical simulations of respiratory airflow and particle transport can be used to improve targeted deposition at the upper respiratory infection site of numerous airborne diseases. Given the need for more patient data from varied demographics, we propose a machine learning-enabled protocol for determining optimal formulation design parameters that may match nasal spray device settings for successful drug delivery. We measured 11 anatomical parameters (including nasopharyngeal volume, nostril heights, and mid-nasal cavity volume) for 10 CT-based nasal geometries representative of the population for this aim. We also ran 160 computational fluid dynamics simulations of drug delivery …

Application Of Gaussian Mixture Models To Simulated Additive Manufacturing, Jason Hasse, Semhar Michael, Anamika Prasad

SDSU Data Science Symposium

Additive manufacturing (AM) is the process of building components through an iterative process of adding material in specific designs. AM has a wide range of process parameters that influence the quality of the component. This work applies Gaussian mixture models to detect clusters of similar stress values within and across components manufactured with varying process parameters. Further, a mixture of regression models is considered to simultaneously find groups and also fit regression within each group. The results are compared with a previous naive approach.

Session 2: The Effect Of Boom Leveling On Spray Dispersion, Travis A. Burgers, Miguel Bustamante, Juan F. Vivanco

SDSU Data Science Symposium

Self-propelled sprayers are commonly used in agriculture to disperse agrichemicals. These sprayers commonly have two boom wings with dozens of nozzles that disperse the chemicals. Automatic boom height systems reduce the variability of agricultural sprayer boom height, which is important to reduce uneven spray dispersion if the boom is not at the target height.

A computational model was created to simulate the spray dispersion under the following conditions: a) one stationary nozzle based on the measured spray pattern from one nozzle, b) one stationary model due to an angled boom, c) superposition of multiple stationary nozzles due an angled boom, …

Symmetric Equations For Evaluating Maximum Torsion Stress Of Rectangular Beams In Compliant Mechanisms, Guimin Chen, Larry L. Howell

Faculty Publications

There are several design equations available for calculating the torsional compliance and the maximum torsion stress of a rectangular cross-section beam, but most depend on the relative magnitude of the two dimensions of the cross-section (i.e.,the thickness and the width). After reviewing the available equations, two thickness-to-width ratio independent equations that are symmetric with respect to the two dimensions are obtained for evaluating the maximum torsion stress

of rectangular cross-section beams. Based on the resulting equations, outside lamina emergent torsional joints are analyzed and some useful design insights are obtained. These equations, together with the previous work on symmetric equations …

Membrane-Enhanced Lamina Emergent Torsional Joints For Surrogate Folds, Guimin Chen, Spencer P. Magleby, Larry L. Howell

Faculty Publications

Lamina emergent compliant mechanisms (including origami-adapted compliant mechanisms) are me- chanical devices that can be fabricated from a planar material (a lamina) and have motion that emerges out of the fabrication plane. Lamina emergent compliant mechanisms often exhibit undesirable para- sitic motions due to the planar fabrication constraint. This work introduces a type of lamina emergent torsion (LET) joint that reduces parasitic motions of lamina emergent mechanisms (LEMs), and presents equations for modeling parasitic motion of LET joints. The membrane joint also makes possible one-way joints that can ensure origami-based mechanisms emerge from their flat state (a change point) into …

Neural Network Flow Optimization Using An Oscillating Cylinder, Meihua Zhang, Zhongquan Charlie Zheng, Yangliu Liu, Xiaoyu Jiang

Mechanical and Aerospace Engineering Student Publications and Presentations

Flow behaviors of a downstream object can be affected significantly by an upstream object in close proximity. Combined with the neural network algorithms, this concept is used for flow control in this study to optimize the aerodynamic performance of a downstream object. Flow with an oscillating cylinder placed upstream is systematically studied because there are multiple control parameters that influence the flow dynamics around the downstream object. These control parameters are used as the input factors of a back-propagation neural network, and then a revised genetic algorithm is applied to find the optimal set of control parameters. In the current …

Halloysite Reinforced Natural Esters For Energy Applications, Jaime Taha-Tijerina, Karla Aviña, Victoria Padilla-Gainza, Aditya Akundi

Informatics and Engineering Systems Faculty Publications

Recently, environmentally friendly and sustainable materials are being developed, searching for biocompatible and efficient materials which could be incorporated into diverse industries and fields. Natural esters are investigated and have emerged as eco-friendly high-performance alternatives to mineral fluids. This research shows the evaluations on thermal transport and tribological properties of halloysite nanotubular structures (HNS) reinforcing natural ester lubricant at various filler fractions (0.01, 0.05, and 0.10 wt.%). Nanolubricant tribotestings were evaluated under two configurations, block-on-ring, and 4-balls, to obtain the coefficient of friction (COF) and wear scar diameter (WSD), respectively. Results indicated improvements, even at merely 0.01 wt.% HNS concentration, …

Effect Of Stress Interaction On Multi-Stress Accelerated Life Test Plan: Assessment Based On Particle Swarm Optimization, Ekene Gabriel Okafor, David Ryan Huitink

Mechanical Engineering Faculty Publications and Presentations

Sustainability of products that seek to maintain ecosystem balance, such as electric vehicles or solar system inverters, often require extensive testing during their developmental stages in a manner that minimizes wastage and drives creativity. Multi-stress accelerated test planning is often used for these products, their subsystems and components if their in-service failures are driven by multiple stress factors. Multi-stress accelerated life testing (ALT) often expedites time to failure for highly reliable products. Many studies assume model parameters that may not be appropriate for the considered stress factors. Most importantly, the effect stress interaction has on the ALT plan is often …

Synthesizing Ti–Ni Alloy Composite Coating On Ti–6al–4v Surface From Laser Surface Modification, Yitao Chen, Joseph William Newkirk, Frank W. Liou

Materials Science and Engineering Faculty Research & Creative Works

In This Work, a Ni-Alloy Deloro-22 Was Laser-Deposited on a Ti–6Al–4V Bar Substrate with Multiple Sets of Laser Processing Parameters. the Purpose Was to Apply Laser Surface Modification to Synthesize Different Combinations of Ductile TiNi and Hard Ti₂Ni Intermetallic Phases on the Surface of Ti–6Al–4V in Order to Obtain Adjustable Surface Properties. Scanning Electron Microscopy, Energy Dispersion Spectroscopy, and X-Ray Diffraction Were Applied to Reveal the Deposited Surface Microstructure and Phase. the Effect of Processing Parameters on the Resultant Compositions of TiNi and Ti₂Ni Was Discussed. the Hardness of the Deposition Was Evaluated, and Comparisons with …

Launching A 3d Printing Program For Students: Recommendations And Best Practices For Libraries, Wilhelmina Randtke, Lee Bareford

Georgia Library Quarterly

The Georgia Southern University Libraries launched a 3D printing program for students in July 2022. Prior to launch, library employees at two of Georgia Southern University’s campuses investigated options for implementing safe, affordable, and sustainable 3D printing in existing academic libraries without retrofitting costly ventilation systems into existing facilities. This article describes the reasons why the Georgia Southern University Libraries thought that a 3D printing program could fulfill a service need for students across university colleges and departments and outlines some of the challenges, best practices, and unique innovations that the library’s employees experienced throughout the program launch process. The …

Glass-Based Biodegradable Pressure Sensor Toward Biomechanical Monitoring With A Controllable Lifetime, Devdatt Chattopadhyay, Jonghyun Park, Chang-Soo Kim

Mechanical and Aerospace Engineering Faculty Research & Creative Works

A New Class of Potentially Implantable Solid-State Sensors is Demonstrated Utilizing Biodegradable Glass as the Main Structural Material. the Device Behavior is Manipulated Via Chemical Decomposition, and Then Physically Disintegrated in a Controlled Manner. It is based on the Capacitive Sensing Mechanism, Comprising an Elastic Insulator between Two Borate-Rich Glass Substrates. This Mesoscale Pressure Sensor is Characterized by a Range of Pressure of Up to 14 MPa in a Phosphate Buffer Solution Environment. the Sensor Exhibits Good Sensitivity and Reversibility Responding to Compressive Pressures and Remains Fully Functional Before a Desired, Sudden Failure Caused by Dissolution. the Operational Lifetime Can …