Mechanical Engineering Commons^™

Free Vibration Analysis Of Rotating Beams Based On The Modified Couple Stress Theory And Coupled Displacement Field, Alireza Babaei, Masoud Arabghahestani

Mechanical Engineering Graduate Research

In this paper, transverse vibration analysis of rotating micro-beam is investigated based on the modified couple stress theory. The simply-supported micro-beam is modeled utilizing Euler-Bernoulli and Timoshenko beam theories. The system is rotating around a fixed axis perpendicular to the axial direction of the beam. For the first time, displacement filed is introduced as a coupled field to the translational field. In other words, the mentioned rotational displacement field is expressed as a proportional function of translational displacement field using first (axial), second (lateral), and third (angular or rotational) velocity factors. Utilizing Hamilton’s approach as a variational method, dynamic-vibration equations …

A Demand-Supply Matching-Based Approach For Mapping Renewable Resources Towards 100% Renewable Grids In 2050, Loiy Al-Ghussain, Adnan Darwish Ahmad, Ahmad M. Abubaker, Mohammad Abujubbeh, Abdulaziz Almalaq, Mohamed A. Mohamed

Mechanical Engineering Graduate Research

Recently, many renewable energy (RE) initiatives around the world are based on general frameworks that accommodate the regional assessment taking into account the mismatch of supply and demand with pre-set goals to reduce energy costs and harmful emissions. Hence, relying entirely on individual assessment and RE deployment scenarios may not be effective. Instead, developing a multi-faceted RE assessment framework is vital to achieving these goals. In this study, a regional RE assessment approach is presented taking into account the mismatch of supply and demand with an emphasis on Photovoltaic (PV) and wind turbine systems. The study incorporates mapping of renewable …

In-Situ Calibrated Modeling Of Residual Stresses Induced In Machining Under Various Cooling And Lubricating Environments, Julius M. Schoop

Mechanical Engineering Faculty Publications

Although many functional characteristics, such as fatigue life and damage resistance depend on residual stresses, there are currently no industrially viable ‘Digital Process Twin’ models (DPTs) capable of efficiently and quickly predicting machining-induced stresses. By leveraging advances in ultra-high-speed in-situ experimental characterization of machining and finishing processes under plane strain (orthogonal/2D) conditions, we have developed a set of physics-based semi-analytical models to predict residual stress evolution in light of the extreme gradients of stress, strain and temperature, which are unique to these thermo-mechanical processes. Initial validation trials of this novel paradigm were carried out in Ti-6Al4V and AISI 4340 alloy …

Scale Model Test To Estimate Thermal Damage By Fire In Aircraft Cargo, Jian Gao, Tsuneyoshi Matsuoka, Yuji Nakamura

Progress in Scale Modeling, an International Journal

The Federal Aviation Administration (FAA) requires fire detectors to alarm within one minute of the start of a fire in cargo compartments of airplanes. To determine whether such alarm timing works, investigations of the thermal damage to ceilings and other structures during the early stage of a fire were accomplished to demonstrate compliance with these FAA regulations. The objective was to test the feasibility of predicting convective heat transfer in early stage of a cargo compartment fire by conducting reduced scale (lab scale) experiments. First, the scaling laws was derived and validated. Then, full-scale and half-scale experiments were performed with …

Extinguishment Of Diffusion Flames Formed Over A Porous Plate Burner Using Rubber Balloons Filled With Inert Gases, Hiroyuki Torikai, Shinya Kudo

Progress in Scale Modeling, an International Journal

We have proposed an inert gas, rubber-balloon extinguishing method which might increase the effectiveness of extinguishing flames and decreasing the amounts of agents needed for fire suppression. Hence, extinguishing experiments have been performed to further clarify possible extinguishing characteristics, mechanisms and scaling effects of this method. Carbon dioxide, nitrogen, argon and helium gases were used as the extinguishing agents. Methane-air and propane-air diffusion flames were formed on two different diameter, round porous plate burner and used as the targets for extinguishment. The extinguishing probabilities were measured, and the extinguishing processes were observed with a high-speed camera. As a result, an …

Effects Of Dimensionless Numbers On Decomposition Of Methane Hydrate, Shoma Shimizu, Genichiro Kushida

Progress in Scale Modeling, an International Journal

It is necessary to elucidate the decomposition and combustion of methane hydrate for fire safety during transportation and storage to utilize it for commercial practice. The amount of methane evolved during the decomposition of methane hydrates is affected by the conditions such as the initial temperature, initial density and ambient temperature. In the present study, the internal temperature of methane hydrate and the amount of methane evolved during its decomposition were investigated by a dimensionless numerical analysis using a transient one-dimensional conduction model from a symmetrical methane hydrate ball heated by ambient air. The numerically calculated central temperature and the …

Fingering Behavior Of Flame Spread Over Solid Combustibles, Tsuneyoshi Matsuoka, Kentaro Nakashima, Takuma Kajimoto, Akihiro Yoshimasa, Yuji Nakamura

Progress in Scale Modeling, an International Journal

In this study, the fingering pattern formation and the following flamelet spreading over three different kinds of thick combustibles, i.e., Poly methacrylate (PMMA), Poly ethylene (PE) and Poly carbonate (PC) were observed and the effective Lewis number correlation was validated. Experiments were performed with a narrow channel apparatus. In addition to the kinds of solid fuel materials, the channel height and the oxidizer velocity were varied as experimental parameters. An image analysis method was developed to quantify the number, diameter and spread rate of the flamelets. Replacing the fuel thickness into the thermal thickness, the effective Lewis number which is …

Data-Driven Tools Guided By First-Principles For Scale Modeling, Sadegh Poozesh

Progress in Scale Modeling, an International Journal

For decades, traditional scale-modeling techniques have been relying on first-principles models (FPMs). FPMs have been used to find non-dimensional numbers (PIs) and identify normalized underlying forces and energies behind the phenomenon in focus. The two main challenges with FPM-based PIs extraction are finding the relevant PIs and proper correlations between PIs. The emergence and surge of data-driven modeling (DDM) provide a new opportunity to leverage experimental data in model development across scales/plants. In this paper, first, the two mentioned issues in PIs development will be elaborated to reveal the gap, and second, a new insight into scale modeling and similarity …

An Advanced Machine Learning Based Energy Management Of Renewable Microgrids Considering Hybrid Electric Vehicles’ Charging Demand, Tianze Lan, Kittisak Jermsittiparsert, Sara T. Al-Rashood, Mostafa Rezaei, Loiy Al-Ghussain, Mohammed A. Mohammed

Mechanical Engineering Graduate Research

Renewable microgrids are new solutions for enhanced security, improved reliability and boosted power quality and operation in power systems. By deploying different sources of renewables such as solar panels and wind units, renewable microgrids can enhance reducing the greenhouse gasses and improve the efficiency. This paper proposes a machine learning based approach for energy management in renewable microgrids considering a reconfigurable structure based on remote switching of tie and sectionalizing. The suggested method considers the advanced support vector machine for modeling and estimating the charging demand of hybrid electric vehicles (HEVs). In order to mitigate the charging effects of HEVs …

Clinical Evaluation Of Respiratory Rate Measurements On Copd (Male) Patients Using Wearable Inkjet-Printed Sensor, Ala'aldeen Al-Halhouli, Loiy Al-Ghussain, Osama Khallouf, Alexander Rabadi, Jafar Alawadi, Haipeng Liu, Khaled Al Oweidat, Fei Chen, Dingchang Zheng

Mechanical Engineering Graduate Research

Introduction: Chronic Obstructive Pulmonary Disease (COPD) is a progressive disease that causes long-term breathing problems. The reliable monitoring of respiratory rate (RR) is very important for the treatment and management of COPD. Based on inkjet printing technology, we have developed a stretchable and wearable sensor that can accurately measure RR on normal subjects. Currently, there is a lack of comprehensive evaluation of stretchable sensors in the monitoring of RR on COPD patients. We aimed to investigate the measurement accuracy of our sensor on COPD patients. Methodology: Thirty-five patients (Mean ± SD of age: 55.25 ± 13.76 years) in different stages …

Numerical Reconstruction Of Spalled Particle Trajectories In An Arc-Jet Environment, Raghava S. C. Davuluri, Sean C. C. Bailey, Kaveh A. Tagavi, Alexandre Martin

Mechanical Engineering Faculty Publications

To evaluate the effects of spallation on ablative material, it is necessary to evaluate the mass loss. To do so, a Lagrangian particle trajectory code is used to reconstruct trajectories that match the experimental data for all kinematic parameters. The results from spallation experiments conducted at the NASA HYMETS facility over a wedge sample were used. A data-driven adaptive methodology was used to adapts the ejection parameters until the numerical trajectory matches the experimental data. The preliminary reconstruction results show that the size of the particles seemed to be correlated with the location of the ejection event. The size of …

Wetting And Brazing Of Yig Ceramics Using Ag–Cuo–Tio2 Metal Filler, Wanqi Zhao, Shuye Zhang, Jian Yang, Tiesong Lin, Dusan P. Sekulic, Peng He

Mechanical Engineering Faculty Publications

The wetting and brazing of Y₃Fe₅O₁₂ (YIG) ceramics with a Ag–8CuO–2TiO₂ filler was investigated for the first time. For comparison, the wettability of a Ag–10CuO filler on YIG ceramics was similarly investigated. The Ag–8CuO–2TiO₂ filler has an equilibrium contact angle of approximately 31 °C on the YIG substrate at 1000 °C; thus, its wettability is excellent. Moreover, its wettability exceeds that of Ag–10CuO. The microstructure and the interfacial structure between the filler and the substrate were determined using scanning electron microscopy, X-ray diffraction, EPMA and transmission electron microscopy. The liquid Ag–8CuO–2TiO₂ filler …

Biofilm And Cell Adhesion Strength On Dental Implant Surfaces Via The Laser Spallation Technique, James D. Boyd, Arnold J. Stromberg, Craig S. Miller, Martha E. Grady

Statistics Faculty Publications

OBJECTIVE: The aims of this study are to quantify the adhesion strength differential between an oral bacterial biofilm and an osteoblast-like cell monolayer to a dental implant-simulant surface and develop a metric that quantifies the biocompatible effect of implant surfaces on bacterial and cell adhesion.

METHODS: High-amplitude short-duration stress waves generated by laser pulse absorption are used to spall bacteria and cells from titanium substrates. By carefully controlling laser fluence and calibration of laser fluence with applied stress, the adhesion difference between Streptococcus mutans biofilms and MG 63 osteoblast-like cell monolayers on smooth and rough titanium substrates is obtained. The …

Energy Consumption And Lifecycle Assessment Comparison Of Cutting Fluids For Drilling Titanium Alloy, Navneet Khanna, Prassan Shah, Jwalant Wadhwa, Anjali Pitroda, Julius M. Schoop, Franci Pusavec

Institute for Sustainable Manufacturing Faculty Publications

This study analyzes four cutting conditions (dry, flood, Liquid CO 2 (LCO2), and Liquid N2 (LN 2)) based on energy consumption and ecological impacts for drilling VT-20, a Titanium alloy. The lower cutting and total energy have been consumed for LCO2 as compared to others. The Life Cycle Assessment (LCA) analysis has been performed using ReCiPe 2016 midpoint (H) to identify the impact of cutting conditions on ecosystem, human health, and natural resources. Cryogenic environment with LN 2 has been found as the most ecological cutting condition next to dry machining, while flood coolant has 94-99% of total impact considering …

Localization Of Stationary Source Of Floor Vibration Using The Steered Response Power Method, Mohammad Royvaran

Theses and Dissertations--Civil Engineering

If the generated vibration in a building exceeds the acceptable limit design for a floor system, it is necessary to identify the source of vibration, a process known as localization. The objective of this study is the localization of stationary vibration sources, and the approach used is the steered response power (SRP) method. This method has already been shown to work well for wireless and acoustical applications to locate transmitter and sound sources, respectively. To the writer’s knowledge, this study is the first application of the SRP method to locate vibration sources using floor vibration measurements. However, because waves behave …

Measurements Of Wind Turbine Wake Evolution And Trajectory During Morning Boundary Layer Transition And Under Wake Steering Conditions Via Unmanned Aerial Vehicles, Stewart Nelson

Theses and Dissertations--Mechanical and Aerospace Engineering

In July of 2019, a flight campaign was conducted using semi-autonomous Unmanned Aerial Vehicles (UAVs) at the Port Alma Kruger Energy wind farm in Ontario, Canada, to study various aspects of wind turbine wake evolution. Horizontal transects across the wakes were measured using modified fixed-wing aircraft fitted with a five-hole probe to measure the wind velocity vector. Reference boundary layer conditions were measured by an octocopter with an assortment of mounted sensors flying vertical profiles upstream of the turbines. Three experiments were conducted during the campaign, which consisted of a study on wake behavior during the morning boundary layer transition, …

Prediction Of Noise Emissions Using Panel Contribution Analysis Supplemented With Scale Modeling, Gong Cheng

Theses and Dissertations--Mechanical and Aerospace Engineering

Panel contribution analysis (PCA) can be used to predict machinery noise emissions, component contributions, and to assess the impact of sound reduction treatments. PCA is a measurement approach that is advantageous for complex machinery that is not easily modeled using conventional numerical analysis approaches. In this research, PCA is combined with scale modeling in order to speed up the necessary measurement work. Moreover, the method can be applied to much larger machinery and noise emissions can be assessed prior to locating and installing the equipment. This eliminates the necessity to use voluminous anechoic chambers.

The machinery is first discretized into …

Kinetics Of Elementary Reactions In Graphene Oxidation And Kinetics Of Oh* In Hydrogen Flames, Siamak Mahmoudi

Theses and Dissertations--Mechanical and Aerospace Engineering

Due to diverse applications of graphene, a kinetic mechanism describing rates of elementary reactions is extremely useful. To achieve that goal the elementary reactions need to be detected and their rates need to be determined. In this work the objectives are to use first-principle tools to find those reactions and analyze their paths in the context of graphene oxidation. Density functional theory (DFT) calculations provide the best approximation to the Schr\"{o}dinger equation, which is not feasible to solve analytically for large molecules like graphene. We have performed these calculations to find stable configurations (geometry optimization) and minimum energy paths between …

Balancing Trade-Offs In One-Stage Production With Processing Time Uncertainty, Jingjing You

Theses and Dissertations--Mechanical and Aerospace Engineering

Stochastic production scheduling faces three challenges, first the inconsistencies among key performance indicators (KPIs), second the trade-offs between the expected return and the risk for a portfolio of KPIs, and third the uncertainty in processing times. Based on two inconsistent KPIs of total completion time (TCT) and variance of completion times (VCT), we propose our trade-off balancing (ToB) heuristic for one-stage production scheduling. Through comprehensive case studies, we show that our ToB heuristic with preference =0.0:0.1:1.0 efficiently and effectively addresses the three challenges. Moreover, our trade-off balancing scheme can be generalized to balance a number of …

Tailoring Texture, Microstructure, And Shape Memory Behavior Of Niti Alloys Fabricated By L-Pbf-Am, Sayed Ehsan Saghaian N.E.

Theses and Dissertations--Mechanical and Aerospace Engineering

Laser Powder Bed Fusion (L-PBF) is one of the most promising Additive Manufacturing (AM) methods to fabricate near net-shape metallic materials for a wide range of applications such as patient-specific medical devices, functionally graded materials, and complex structures. NiTi shape memory alloys (SMAs) are of great interest due to a combination of unique features, such as superelasticity, shape memory effect, high ductility, work output, corrosion resistance, and biocompatibility that could be employed in many applications in automotive, aerospace, and biomedical industries. Due to the difficulties with traditional machining and forming of NiTi components, the ability to fabricate complex parts, tailor …

A Theoretical Study On Integration And Optimization Of Gas Turbine Problems With Solar Energy System, Ahmad M. Abubaker

Theses and Dissertations--Mechanical and Aerospace Engineering

Gas Turbine (GT) power plants suffer from sensitivity to ambient-air temperatures, high fuel consumption, and a high amount of waste heat dumped into the ambient. Various solutions were proposed to solve these drawbacks, which could simultaneously solve at most two problems, usually at the expense of the third. For instance, inlet-air cooling can reduce ambient-air temperatures but will result in increased fuel consumption. However, in this work, a novel cascaded system was integrated into a combined cycle, capable of simultaneously solving all the aforementioned GT drawbacks. Parabolic trough collectors were used to preheat the air at the combustion chamber inlet …

The Role Of Live Conifer Fuels In Crown Fires Spread, Adnan Darwish Ahmad

Theses and Dissertations--Mechanical and Aerospace Engineering

Live foliage for some tree and shrub species can support flaming fire spread at much higher moisture content than dead fuel materials. However, the role of live fuels in forest fires has been controversial in the past decades. Although ignition and spread statistical data for live and dead fuels exist in the literature, a clear understanding of the fundamental difference in the burning behavior is missing. To illuminate the role of live fuel on forest fire spreading, a laboratory ignition experiment was designed to examine the burning behavior of live Norway spruce needles. A schlieren-Infrared combined measurement apparatus was developed …

Use Of Microscale Hydrophobic Surface Features For Integration Of 3d Cell Culture Into Multi-Functional Microfluidic Devices, Soroosh Torabi

Theses and Dissertations--Mechanical and Aerospace Engineering

3D cell culture and microfluidics both represent powerful tools for replicating critical components of the cell microenvironment; however, challenges involved in integration of the two and compatibility with standard tissue culture protocols still represent a steep barrier to widespread adoption. Here we demonstrate the use of engineered surface roughness in the form of microfluidic channels to integrate 3D cell-laden hydrogels and microfluidic fluid delivery. When a liquid hydrogel precursor solution is pipetted onto a surface containing open microfluidic channels, the solid/liquid/air interface becomes pinned at sharp edges such that the hydrogel forms the “fourth wall” of the channels upon solidification. …

Multiscale Finite Element Modeling Of Active Contraction In Striated Muscle, Charles Kurtis Mann

Theses and Dissertations--Mechanical and Aerospace Engineering

Greater than one in three American adults have at least one type of cardiovascular disease, a major cause of morbidity. Computational cardiac mechanics has become an important part of the research effort to understand the heart’s response to mechanical stimuli and as an extension, disease progression and potential therapies. To this end, the present work aims to extend these efforts by implementing a cell level contractile model in which active stress generation in muscle tissue is driven by half-sarcomere mechanics. This is accomplished by enhancing the MyoSim model of actin and myosin in order to produce a multiscale model. This …

Evaluation Of Radiative Conductivity Inside A Porous Media With The Effect Of Participating Medium Based On Microscale Imaging, Mingping Zheng

Theses and Dissertations--Mechanical and Aerospace Engineering

Space vehicles will experience high loads of heat while entering the planetary atmosphere. At such high temperature, radiation becomes the dominant mode of heat transfer. Since the atmospheric entry environment is nearly impossible to duplicate in a laboratory environment, a numerical model to evaluate thermal performance of the thermal protection system was established. The model simulates the radiative heat transfer process in highly porous media, and the process also takes into account the influence of the participating media. An iterative approach and periodic boundary conditions are used to solve The unbalanced heat flux problem. CT scanned microscale Fiberform and artificial …

Viscoelasticity Of Ptfe-Based Face Seals, Bo Tan

Theses and Dissertations--Mechanical and Aerospace Engineering

PTFE-based materials are widely used in areas of tribology, particularly in seal and bearing applications because of their outstanding self-lubricating properties. Often in dynamic seal applications there is a need for ultra-low mechanical friction loss between the sealing surfaces. Due to its extremely low friction coefficient, there is interest in employing Polytetrafluoroethylene (PTFE) materials in such applications. One challenging aspect of employing PTFE is that these materials are viscoelastic and plastic. This dissertation concentrates on the modeling of viscoelastic material response when used as mechanical face seals with a focus on PTFE-based materials. First, the viscoelastic characteristics are measured through …

Study Of Stress-Based Fiber Reorientation Law In A Finite Element Model Of Cardiac Tissue, Alexus Lori Rockward

Theses and Dissertations--Mechanical and Aerospace Engineering

Myofiber organization in the heart plays an important role in achieving and maintaining physiological cardiac function. In many cardiac disease states, myofibers and particularly cardiomyocytes are disorganized in chaotic patterns, a phenotype known broadly as myocardial disarray. In familial hypertrophic cardiomyopathy (HCM), this disorganization in the form of myocyte disarray is thought to contribute to impaired cardiac function and the development of arrhythmia during disease progression. However, the mechanisms regarding fiber reorientation in the heart are yet still unclear, and few adaptative laws have been created to explore these mechanisms. A stretch-based law was developed with the aim of achieving …

Waste Heat Recovery Of Industrial Regenerative Thermal Oxidizer (Rto), A Case Study, James Trimpe Jr.

Theses and Dissertations--Mechanical and Aerospace Engineering

Industrial processes that utilize and release hazardous compounds into the atmosphere are required to break down those compounds before exhausting them from their facilities. An industry-recognized method to break down those hazardous compounds is through thermal oxidation. Thermal oxidation is a process where the compounds are exposed to their auto-ignition temperature in an oxygen-rich environment and combust. The output of thermal oxidation is carbon dioxide, water vapor, and heat. Thermal oxidizers are equipment that performs the thermal oxidation process. The heat output from thermal oxidizers is wasted if directly exhausted into the atmosphere. Regenerative thermal oxidizers (RTOs) use the waste …

Redesigning Products To Optimize Sustainable Performance In Multi-Generational Closed-Loop Production For Advancing The Circular Economy, Buddhika Minendra Hapuwatte

Theses and Dissertations--Mechanical and Aerospace Engineering

Sustainable manufacturing and the circular economy concepts promote efficient and effective resource use to minimize the adverse economic, environmental, and social impacts of alarmingly increasing consumption rates. Product design is the key to implement these transformations in manufacturing. However, the currently available sustainable and circular design methods are not comprehensive and inadequate—especially for multi-generational products. Therefore, designing sustainable products optimized for circular and closed-loop production systems is a challenging task. The 6Rs concept introduced ‘Redesign’ to modify a product’s engineering specifications and allow sustainable utilization of the end-of-use resources from previous generations, thus closing the production loop. Therefore, the objective …

Experimental Investigation Of Image Distortion In A Mach 6 Hypersonic Flow, Ricky W. Green Ii

Theses and Dissertations--Mechanical and Aerospace Engineering

The image distortion that is inherently present when imaging through a flow field at hypersonic speeds was investigated. The original problem involves observation of the outside world from the inside an aircraft moving at hypersonic speeds. For this work, a Mach 6 hypersonic wind tunnel at Wright Patterson Air Force Base (WPAFB) was used and optical patterns were imaged with and without flow field characteristics. Two test campaigns were scheduled to conduct experiments that would provide answers to the proposed problem of the effect on observable aberrations through flow fields.

During the first test campaign, October 2017, optical patterns were …