Mechanical Engineering Commons^™

Rebar Impalement Safety, Spencer C. Nefores, Steven M. Hoover

Industrial and Manufacturing Engineering

This project is sponsored by Webcor with the purpose of finding a better solution to rebar impalement safety. The current rebar impalement safety caps being used by Webcor were found to frequently fall off after being installed. This results in workers being exposed to the hazard for longer than desired. The research that has been done by the team showed that rebar impalement is a serious hazard and results in injury or death every year. Site visits and interviews were performed to aid in understanding the problem and designing solutions. The customer needs, current state of the problem, existing solutions, …

Parklets San Luis, Owen Kenny, Preston Jag Stebel, Leonidas Goodman, Lukas Braun

Industrial and Manufacturing Engineering

Downtown San Luis Obispo has been a popular destination for tourists, students, families, and roadtrippers. However, according to Ryan Betz, Interim Assistant to the City Manager, foot traffic and retail business revenue has been decreasing. Downtown SLO does not have enough free public spaces. Recent projects such as sidewalk bump outs and lighted crosswalks have aimed at making SLO more pedestrian accessible, but they have not actually made downtown more pleasurable. These projects have not seemed to drive any more business or traffic downtown. There are a myriad of ways to rectify this; studies show that having a free place …

Hydronic Service Valve Product Development, Mark Hunsaker

Construction Management

Since the inception of modern mechanical and HVAC systems, maintenance and repairs have been prevalent in both contracting and facility operations. The average life of HVAC equipment is fractional compared to the life of buildings as construction technologies improve. Traditionally, the serviceability of heating and cooling equipment has entailed the significant amounts of labor and materials to disruptively drain or freeze hydronic systems in order to cut in means of bypassing the main system, swapping out equipment, or repair. The intent of this project is to explore alternative methods to forgo the aforementioned negative impacts of service and to improve …

Design And Development Of A Robotic Platform For General Neurosurgical Procedures, Mehbodniya Amir Hossein

Student Works (2020-2029)

For the first time in 1985, robots were introduced to the neurosurgical operating rooms. Since then this field of robotics have advanced with new technologies with better accuracy and safety. However, developing robots for neurosurgery is a challenging task due to the sensitive nature of these applications and additionally their high cost of development. A typical neurosurgical robot costs millions of dollars in 2018, even though the costs of components and calculations have been lowered tremendously. This is mainly due to focus of current neurosurgical robots on few highly precise and specific surgical tasks which makes their use limited. In …

Design And Analysis Of A Compact Combustor For Integration With A Jetcat P90 Rxi, Daniel Holobeny

Theses and Dissertations

Ultra Compact Combustors are a novel approach to modern gas turbine combustor designs that look to reduce the overall combustor length and weight. A previous study integrated an Ultra Compact Combustor into a JetCat P90 RXi turbine engine and achieved self-sustained operation with a length savings of 33% relative to the stock combustor. However, that combustor could not operate across the full stock engine performance range due to flameout at increased mass ow rates as reactions were pushed out of the primary zone. To ensure reactions stayed in the primary zone, a new design with a larger combustor volume was …

Lip Thrust Apparatus, Ian M. Wilson, Alvin K. Cheong

Mechanical Engineering

This document contains the background information, defined scope of work, preliminary design philosophy, conceptual design development, and final design choices along with its corresponding manufacturing and design verification plans. It also includes the preliminary testing and prototyping necessary in bringing our verification prototype to its final configuration for delivery. Finally, it includes the entire manufacturing process followed in creating the final project and the extensive testing performed to ensure it meets the defined engineering specifications. The aerodynamic phenomenon being analyzed and demonstrated in our final deliverable can be seen in a scenario where when a propeller is enclosed in a …

Experimental Characterization Of The Electrostatic Levitation Force In Mems Transducers, Meysam Daeichin, Ronald Miles, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

In this study, a two-step experimental procedure is described to determine the electrostatic levitation force in MEMS transducers. In these two steps, the microstructure is excited quasi-statically and dynamically and its response is used to derive the electrostatic force. The experimental results are obtained for a 1 by 1 plate that employs 112 levitation units. The experimentally obtained force is used in a lumped parameter model to find the microstructure response when it is subjected to different dynamical loads. The natural frequency and the damping ratios in the model are identified from the experimental results. The results show this procedure …

An Integrated Computational Materials Engineering-Anchored Closed-Loop Method For Design Of Aluminum Alloys For Additive Manufacturing, Saket Thapliyal, Mageshwari Komarasamy, Shivakant Shukla, Le Zhou, Holden Hyer, Sharon Park, Yongho Sohn, Rajiv S. Mishra

Mechanical Engineering Faculty Research and Publications

A closed-loop approach based on integrated computational material engineering was used to design, fabricate and characterize an Al–1.5Cu–0.8Sc–0.4Zr (wt%) alloy for laser powder bed fusion additive manufacturing (AM). Finalization of composition and prediction of solidification behavior and mechanical properties were done using calculation of phase diagrams (CALPHAD) and analytical tools. The microstructure of the printed alloy in as-built condition consisted of crack-free regions with fine-equiaxed grains which was consistent with CALPHAD results. Yield strength (YS) of ~349 ± 8 MPa was also in more than 90% agreement with predicted YS. The findings demonstrate an efficient methodology for application-based alloy design …

Piezoelectric Energy Harvesting Suspension System For A Half Car Model: Analytical And Experimental Study, Doaa Ali Nasser Al-Yafeai

Mechanical Engineering Theses

One of the essential techniques for energy harvesting is the clean energy collection from ambient vibration. Recently, piezoelectric energy harvesting systems became a hot topic and attracted many researchers. This is due to their simple structure, relatively high output power among the other mechanisms (electromagnetic and electrostatic), compatibility with MEMS, and operation in a wide frequency range. The main objective of the current work is to develop a mathematical model to evaluate the potential of harvesting power from the car suspension system. Quarter and half car models with a built-in piezoelectric stack were modeled mathematically using Laplace transformation and simulated …

Use Of Body Composition Imaging To Calculate 3-D Inertial Parameters For Inverse Dynamic Analysis Of Youth Pitching Arm Kinetics, Dalton James Jennings

Master's Theses

The objectives of this study were to 1) calculate participant-specific segment inertial parameters using dual energy X-ray absorptiometry (DXA) data (referred to as full DXA-driven parameters) and compare the pitching arm kinetic predictions using full DXA-driven inverse dynamics vs scaled, DXA mass-driven (using DXA masses but scaled centers of mass and radii of gyration), and DXA scaled inverse dynamics(ID) (using the full DXA-driven inertial parameters averaged across all participants), 2) examine associations between full DXA-driven kinetics and body mass index (BMI) and 3) examine associations between full DXA-driven kinetics and segment mass index (SMI). Eighteen 10- to 11- year-olds pitched …

Hybrid Phase-Change Lattice Boltzmann Simulation Of Vapor Condensation On Vertical Subcooled Walls, Wandong Zhao, Yuan Gao, Ruijie Li, Songgang Qiu, Yin Zhang, Ben Xu

Mechanical Engineering Faculty Publications

Saturated vapor condensation on homogenous and heterogeneous subcooled walls is presented in this study by adopting a hybrid phase-change multiple-relaxation-time Lattice Boltzmann model. The effects of wall wettability on the condensation process, including droplets’ growth, coalescence and falling, and the influence of vapor flow to condensation are investigated. The results demonstrate that the heat fluxes around the triple-phase contact lines are higher than that in other cold areas in homogeneous subcooled walls, which actually indicates the fact that filmwise condensation is preventing the continuous condensation process. Furthermore, the dropwise condensation can be formed more easily on the heterogeneous surface with …

Architecture And Trilogy Of (Law, Theory And Hypothesis), Ahmed Hashim Hameed

Al-Esraa University College Journal for Engineering Sciences

The general cognitive expositions had focused on the study of the general knowledge frameworks of the field of architecture, with both concepts that influencing and influenced by them, which used to contain them without referring to their intellectual origins in order to understand their general effect and their role in the cognitive enrichment to the architectural field. This, in return, showed the importance of direction to study the role, influence and effect of trilogy (Law, theory and hypothesis) in the field of architecture, according to their general reality knowledge and their specific theoretical and intellectual characteristics. This research deals with …

The Impact Of Spatial Location Of Functions To Identify Architectural Forms As A Landmark (Case Study - Contemporary Islamic Architecture -), Ibtisam Abdulelah Mohammed Al Khafaji, Maha Haki Ismaeil

Al-Esraa University College Journal for Engineering Sciences

This research discusses the impact of spatial location of functions inside architectural form to enhance visual legibility and how it can improve the possibilities of identifying them as a landmark. The absence of a clear conceptual frame which can be used to describe this impact forms the basic research problem. The objective aim of the research is to clarify and describe this impact. To achieve this objective aim, an analytical process was used. We supposed that spatial location of functions enhances visual legibility of forms, then improves our possibility of identifying them as a landmark. For applying the conceptual frame, …

Effect Of Loading Level Of Hybrid Reinforced Concrete Deep Beams Under Repeated Loading, Sawsan Akram Hassan, Ghsoon Ali Faroun

Al-Esraa University College Journal for Engineering Sciences

This research is devoted to investigating the experimental and theoretical behavior of hybrid deep beams under monotonic and repeated two-point loading. The dimensions and the flexural reinforcement of the deep beams were kept constant. In this work, the idea of a hybrid beam is completely different. Two types of concrete were used but not in the cross-section. The first type, which is fiberous concrete (FC), was used in casting beam sides (shear spans), while the second type was conventional concrete (CC) which was used in the middle portion of the beam (between two shear spans). This was done to strengthen …

Reverse Osmosis Method For Sulphate Re-Moval From Treated Wastewater Of Al-Doura Refinery, Rana Mohammed Rasheed

Al-Esraa University College Journal for Engineering Sciences

The treated wastewater by the industrial Wastewater Treatment Plant (WWTP) commonly named (INGECO) in Al-Doura refinery suffers from highly sulfate concentrations that exceed the EPA specified limits of 250 mg/L. Therefore, laboratory water quality historical data have been reviewed and analyzed to determine the annual rate, maximum, and peak sulfate concentrations that were found to be 360 mg/L, 425 mg/L, and 550 mg/L, respectively. Through field inspection aimed at specifying the reasons for the high sulfate concentrations in the wastewater of most refinery process units, it was found that the maximum required sulfate remaining concentration should not exceed 10 mg/L …

Comparison Between Regular And Irregular Configuration In Earthquake Resistant Design, Ali Nur-Aldeen Azeez, Ali Mohsen Jaafer Al-Khafaji

Al-Esraa University College Journal for Engineering Sciences

Earthquake-resistant design is one of the greatest challenges that must be considered by the Architect because it is a serious natural disaster that affects the stability and durability of the building. Due to the connection between the seismic behavior of buildings with its formal configuration and the differences in seismic resistance between regular and irregular buildings, the research problem presented as the confusion of seismic behavior of irregular buildings and their difference from the regular buildings when earthquakes occur. The aim of the research is to clarify the differences between regular and irregular configurations, also clarifying the design considerations in …

Pedestrian Movement Within Residential Areas, Abd Alali Hamza Mohamed

Al-Esraa University College Journal for Engineering Sciences

The network of transport within residential areas, especially within residential neighborhoods, consists mainly of roads designed to provide relative safety for road users and to prioritize solutions that enhance safety. It is believed that the pedestrian movement network should be separated from the car movement network, with a focus on road design, pedestrian paths, and the types of vehicles used in these areas to ensure safety. This research explores the solutions developed in the planning of roads and walkways in traditional housing schemes within the urban fabric of old cities. It examines the approaches and conclusions of modern models of …

Stable Adaptive Control Systems In The Presence Of Unmodeled And Actuator Dynamics, Kadriye Merve Dogan

USF Tampa Graduate Theses and Dissertations

In adaptive control of physical systems, it is well-known that the presence of actuator and/or unmodeled dynamics in feedback loops can yield to unstable closed-loop system trajectories. Motivated by this standpoint, this dissertation presents novel model reference and distributed adaptive control architectures with stability and performance guarantees for uncertain sole and multiagent dynamical systems with unmodeled and/or actuator dynamics.

Specifically, model reference and distributed adaptive control architectures are powerful theoretical tools for both sole and multiagent systems, where they have the capability to suppress the effect of exogenous disturbances and system uncertainties for achieving a desired level of closed-loop system …

On The Spreading Of Non-Canonical Thermals From Direct Numerical Simulations, Kai Liu, ‪Nadim Zgheib, S. Balachandar

Mechanical Engineering Faculty Publications

We present results from direct numerical simulations on laminar and turbulent non-canonical thermals with an initial rectangular density distribution at a Reynolds number of Re = 500 and Re = 5000, respectively. We find the non-canonical shape to induce strong azimuthal variations in the thermal for both the laminar and turbulent cases. These include noticeable differences in downward and horizontal propagation speeds as well as differences in the strength of the vortex tube. These differences persist over a significant period of time and help generate a cross-flow component that is otherwise not present in canonical cases. The cross-flow component is …

Numerical Investigation Of Vortex-Induced Vibration Of A Vertical Riser In Uniform Flow At High Reynolds Numbers, Jerónimo Domingo, Luis Pérez-Rojas, H. R. Díaz-Ojeda

Journal of Marine Science and Technology–Taiwan

This work presents a numerical study on the vortex-induced vibration (VIV) phenomenon of synchronization of a vertical, flexible, circular cylinder with a length-to-diameter ratio of 475, being free to move along the in-line (IL) and cross-flow (CF) directions for Reynolds numbers of 42K, 84K and 126K. It is found that the dominant mode numbers, the maximum root mean square amplitudes, the dominant frequencies and the lift coefficient increase with the Reynolds number, but the drag coefficient decreases. The in-line response shows a main frequency component at twice the cross-flow frequency. At some Reynolds number value and riser span location, a …

Verification And Validation Of A Resistance Model For Tanker 17.500 Dwt, D. Purnamasari, I. K. A. P. Utama, I. K. Suastika

Journal of Marine Science and Technology–Taiwan

Verification and validation study was performed based on to the methodology and procedures of the International Towing Tank Conference. The verification was based on a mesh dependency study, Richardson extrapolations, and uncertainty analysis with factor of safety methods. The validation was performed by comparing the experimental data of the 17.500 DWT tanker, tested in calm water at the Indonesian Hydrodynamic Laboratory, with computational data. The verification and validation results revealed that it was possible to improve the reliability of the numerical simulation by reducing the errors and uncertainties related to resistance prediction.

Fracture Toughness Analysis Of Epoxy-Recycled Rubber-Based Composite Reinforced With Graphene Nanoplatelets For Structural Applications In Automotive And Aeronautics, Alaeddin Burak Irez, Emin Bayraktar, Ibrahim Miskioglu

Michigan Tech Publications, Part 1

This study proposes a new design of lightweight and cost-efficient composite materials for the aeronautic industry utilizing recycled fresh scrap rubber, epoxy resin, and graphene nanoplatelets (GnPs). After manufacturing the composites, their bending strength and fracture characteristics were investigated by three-point bending (3PB) tests. Halpin-Tsai homogenization adapted to composites containing GnPs was used to estimate the moduli of the composites, and satisfactory agreement with the 3PB test results was observed. In addition, 3PB tests were simulated by finite element method incorporating the Halpin-Tsai homogenization, and the resulting stress-strain curves were compared with the experimental results. Mechanical test results showed that …

Publisher Correction: Evaporation Of A Sessile Droplet On A Slope., Mitch Timm, Esmaeil Dehdashti, Amir Jarrahi Darban, Hassan Masoud

Michigan Tech Publications, Part 1

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Dispersion Tuning And Route Reconfiguration Of Acoustic Waves In Valley Topological Phononic Crystals, Zhenhua Tian, Chen Shen, Junfei Li, Eric Reit, Hunter Bachman, Joshua E. S. Socolar, Steven A. Crummer, Tony Jun Huang

Henry M. Rowan College of Engineering Departmental Research

The valley degree of freedom in crystals offers great potential for manipulating classical waves, however, few studies have investigated valley states with complex wavenumbers, valley states in graded systems, or dispersion tuning for valley states. Here, we present tunable valley phononic crystals (PCs) composed of hybrid channel-cavity cells with three tunable parameters. Our PCs support valley states and Dirac cones with complex wavenumbers. They can be configured to form chirped valley PCs in which edge modes are slowed to zero group velocity states, where the energy at different frequencies accumulates at different designated locations. They enable multiple functionalities, including tuning …

Shallow Water Seafloor Geodesy: Gps On An Anchored Spar Buoy, Surui Xie

USF Tampa Graduate Theses and Dissertations

Measuring seafloor motion in shallow coastal water is challenging due to strong and highly variable oceanographic effects. Such measurements are potentially useful for monitoring near-shore coastal subsidence, subsidence due to petroleum withdrawal, strain accumulation/release processes in marine shelves and submerged volcanoes, and certain fresh water applications, such as volcano deformation in caldera-hosted lakes. I participated in a project to develop a seafloor geodetic system for this environment based on an anchored spar buoy topped by high precision GPS. Orientation of the buoy is measured using a digital compass that provides heading, pitch, and roll information. The combined orientation and GPS …

Laser-Assisted Micromachining Systems And Methods, Yung C. Shin, Xiangyang Dong

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Laser-assisted micromachining methods and systems capable of providing flexible beam positioning and low incident angles. Such laser-assisted micromachining systems preferably include a laser beam source, a cutting tool, means for engaging a workpiece with the cutting tool, optical elements arranged to define a path of a laser beam emitted by the laser beam source wherein the optical elements include at least a first mirror mounted in fixed relation to the laser beam source, and means for adjustably mounting a second mirror to project the laser beam onto the workpiece in proximity to the cutting tool and at an incidence angle …

Mission-Oriented Multirobot Adaptive Navigation Of Scalar Fields, Robert Mcdonald

Engineering Ph.D. Theses

Scalar fields are spatial regions where each point has an associated physical value. These fields often contain features of interest, such as local extrema and contours with a value of significance. Traditional navigation techniques require robots to exhaustively search these regions to find the areas of significance, while adaptive navigation allows them to move directly to the points of interest based on measurements of the field taken during the navigation process. This work expands existing adaptive navigation techniques by adding a finite state machine layer to the control architecture, and using it as a discrete mode controller; the state machine …

Angular Correlation Using Rogers-Szego-Chaos, Christine Schmid, Kyle J. Demars

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Polynomial chaos expresses a probability density function (pdf) as a linear combination of basis polynomials. If the density and basis polynomials are over the same field, any set of basis polynomials can describe the pdf; however, the most logical choice of polynomials is the family that is orthogonal with respect to the pdf. This problem is well-studied over the field of real numbers and has been shown to be valid for the complex unit circle in one dimension. The current framework for circular polynomial chaos is extended to multiple angular dimensions with the inclusion of correlation terms. Uncertainty propagation of …

A Quasi-Monte Carlo Solver For Thermal Radiation In Participating Media, Joseph Farmer, Somesh Roy

Mechanical Engineering Faculty Research and Publications

The Monte Carlo (MC) method is the most accurate method for resolving radiative heat transfer in participating media. However, it is also computationally prohibitive in large-scale simulations. To alleviate this, this study proposes a quasi-Monte Carlo (QMC) method for thermal radiation in participating media with a focus on combustion-related problems. The QMC method employs low-discrepancy sequences (LDS) in place of the traditional random numbers. Three different low-discrepancy sequences – Sobol, Halton, and Niederreiter – were examined as part of this work. The developed QMC method was first validated against analytical solutions of radiative heat transfer in several one-dimensional configurations. Then …

Dislocation-Oxide Interaction In Y2o3 Embedded Fe: A Molecular Dynamics Simulation Study, M. Mustafa Azeem, Qingyu Wang, Zhongyu Li, Yue Zhang

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

Oxide dispersed strengthened (ODS) steel is an important candidate for Gen-IV reactors. Oxide embedded in Fe can help to trap irradiation defects and enhances the strength of steel. It was observed in this study that the size of oxide has a profound impact on the depinning mechanism. For smaller sizes, the oxide acts as a void; thus, letting the dislocation bypass without any shear. On the other hand, oxides larger than 2 nm generate new dislocation segments around themselves. The depinning is similar to that of Orowan mechanism and the strengthening effect is likely to be greater for larger oxides. …