Engineering Commons^™

Homogenization Of Composite And Cellular Materials Incorporating Microstructure And Surface Energy Effects, Ahmad Gad

Mechanical Engineering Research Theses and Dissertations

In the last few decades, the popularity of composite and cellular materials has rapidly increased through their widespread applications in multiple engineering fields including aerospace, automotive, civil and biomedical. However, to a large extent, the success of their practical applications depends on our ability to predict their mechanical behavior by using high-fidelity mechanics models.

Micromechanical modeling of composite and cellular materials is a challenging task due to the heterogeneous nature of such materials and the interactions among various constituent phases at the microscopic level, which result in non-homogeneous deformation, strain and stress fields. Therefore, it is necessary to develop simple …

Work In Progress: Development Of A General Education First-Year Design Course, Courtney Hollar, Sondra M. Miller

Civil Engineering Faculty Publications and Presentations

We discuss in this Work in Progress paper the development of a new first-year engineering course at Boise State University. ENGR 180 Communication in Design Thinking, was developed in order to emphasize the importance of communication throughout the design process. Communication with the client at the start of the design process occurs in order to understand the problem to be solved. The team and other stakeholders continuously communicate in order to work toward developing a prototype to solve the problem. The ability to effectively communicate is equally as important to the design of the final product. The development of ENGR …

Adaptive Robotic Chassis (Arc), Darran Casey, Ryan Ku, Noah Kane Manuel, Isabella Morales, James Reimer, Lavelle Simmons

Interdisciplinary Design Senior Theses

The ARC is a width adjusting agricultural robot and accommodates auxiliary functions for supporting crop production and maintenance. Easily interchangeable payloads and components provide a modular solution to perform focused crop surveying functions with the potential for herbicide distribution, weeding, and harvesting while driving through varying crop rows. The potential auxiliary functions will be implemented by future teams with this year's effort being put toward finishing the physical chassis. The final product was successfully designed to weigh approximately 600 pounds targeting rolling speeds of0.90 fps to 2.30 fps with proof of concept shown in testing consisting of chain drive attached …

Heavy Lift Drone, Sam Carhart, David Cooper, Luis Gaitan, Michael Kaliterna, Sami Lama, Paul Rogel-Herrera, Yuya Yabe

Interdisciplinary Design Senior Theses

Despite the rapid rise in the number of drones in the past few years, there has been little work done to produce a drone that is optimized for the FAA' s 55 lb upper takeoff limit. This gap in the market is one that the Heavy Lift Drone (HLD) fills - a light-weight, higher payload capability, and inexpensive drone to be used in commercial applications - most notably irrigation monitoring. The HLD is a contra-rotating hexagonal configuration system featuring two levels of propellers that allow for larger propeller diameter and generate greater lift. After performing extensive finite element analyses and …

Application Of Optimal Switching Using Adaptive Dynamic Programming In Power Electronics, Ataollah Gogani Khiabani

Mechanical Engineering Research Theses and Dissertations

In this dissertation, optimal switching in switched systems using adaptive dynamic programming (ADP) is presented. Two applications in power electronics, namely single-phase inverter control and permanent magnet synchronous motor (PMSM) control are studied using ADP. In both applications, the objective of the control problem is to design an optimal switching controller, which is also relatively robust to parameter uncertainties and disturbances in the system. An inverter is used to convert the direct current (DC) voltage to an alternating current (AC) voltage. The control scheme of the single-phase inverter uses a single function approximator, called critic, to evaluate the optimal cost …

Control And Locomotion Of Inertially And Magnetically Actuated Multi-Scale Robotic Systems, Ehab Al Khatib

Mechanical Engineering Research Theses and Dissertations

In this research, two actuation systems were introduced, inertial and magnetic actuation. In the inertial actuation, the robot used the transfer of momentum to navigate, and this momentum could be generated by spinning masses and wheels. Recent studies in our System Laboratory proved that a wide range of inertially actuated locomotion systems could be generated. This can be achieved by using a family tree approach, starting from a very simple system, and progressively evolving it to more complex ones. The motion diversity of these robots inspired us to extend their locomotion from a macro scale to millimeter and micro scales. …

Utilizing The Product Development Process To Bring An Idea From Concept To Production, Sydney Ferguson, Jackson Sneed

Honors Theses

The purpose of this thesis is to document and discuss the five-stage product development process starting with defining a problem and resulting in manufacturing a final product for sale as it was implemented in the Portable Fire Pit Center for Manufacturing Excellence Senior Capstone Project. This project was carried out over the course of the Fall 2019 and Spring 2020 semesters by a team consisting of three Undergraduate Mechanical Engineering majors and two Undergraduate Accountancy majors. The ultimate goal of the project was to carry out a full production run of the Portable Fire Pit outputting fifteen units meeting retail …

Critical Point Identification In 3d Velocity Fields, Mohammadreza Zharfa

Mechanical Engineering Research Theses and Dissertations

Classification of flow fields involving strong vortices such as those from bluff body wakes and animal locomotion can provide important insight to their hydrodynamic behavior. Previous work has successfully classified 2D flow fields based on critical points of the velocity field and the structure of an associated weighted graph using the critical points as vertices. The present work focuses on extension of this approach to 3D flows. To this end, we have used the Gauss-Bonnet theorem to find critical points and their indices in the 3D velocity vector field, which functions similarly to the Poincare-Bendixon theorem in 2D flow fields. …

Stability Analysis, Dynamic Modeling, And Kinematic Analysis Of Hydraulically Amplified Dielectric Elastomer Actuators And Robot Manipulators, Amir Hosein Zamanian

Mechanical Engineering Research Theses and Dissertations

In this dissertation, we have proposed a new dielectric elastomer actuator design and model that couples electrostatics, fluid mechanics, linear and nonlinear elastic deformations. The internal hydraulic pressure can amplify the structural deformation generated by induced electrostatic forces (Maxwell pressure), given the name of this class of actuators, hydraulically amplified dielectric elastomer actuators (HADEAs).

First, we developed novel lumped-parameter models (LPMs) using linear and hyper-elastic material models and second compared the LPM results with finite element analysis in quasi-static simulations. We analytically expressed the conditions for the snap-through instability in the HADEA, which appears after exceeding a certain voltage applied …

Basil Leaf Automation, Andrew Soong, Chris Nelson, John Goldsberry, Kalle Suzuki, Nikolas Abenoja, Sherene Victor, Simon Liu

Interdisciplinary Design Senior Theses

Recent population and wage increases have forced farmers to grow more food without a proportionate increase in work force. Automation is a key factor in reducing cost and increasing efficiency. In this paper, we explore our automation solution that utilizes position manipulation and vision processing to identify, pick up, and drop a leaf into a can. Two stepper motors and a linear actuator drove the three-dimensional actuation. Leaf and can recognition were accomplished through edge detection and machine learning algorithms. Testing proved subsystem-level functionality and proof of concept of a delicate autonomous pick-and-place robot.

Design Of A Greywater-Fed Hydroponics System, Alex Estrada, Katya Fairchok, Andrew Feldmeth, Andrew Jezak

Interdisciplinary Design Senior Theses

To combat issues of local water insecurity, a hydroponics system was designed in partnership with LEAP 5 High School in Jane Furse, South Africa. Climate change, increasing human population, and continued environmental degradation all threaten access to clean drinking water. Approximately seventy percent of all freshwater is used for agriculture globally, thus threatening food security especially in developing countries where access to water is potentially volatile. The hydroponics garden system utilizes sustainable materials, a self-monitoring temperature controls system, and greywater input, to act as an educational tool for students and significantly reduce freshwater use compared to traditional, in-ground agriculture. An …

Computational Assessment Of Aortic Valve Function And Mechanics Under Hypertension, Saurav Kadel

Browse all Theses and Dissertations

Calcific aortic valve disease (CAVD), the most common valvular heart disorder, is associated with complications such as stroke, heart attack, aortic aneurysm, left ventricular hypertrophy, and ultimately death. While hypertension has been identified as a major risk factor for CAVD, the mechanisms by which it may promote calcification are still unknown. Given the sensitivity of valvular tissue to mechanical stress alterations, the hemodynamic abnormalities linked to hypertension may play a role in the development of CAVD. Further, the effects of hypertension on the left ventricular functionality and coronary flow resistance remain largely uninvestigated. Hence, the objectives of this thesis were …

Thermal Modeling Of Coordinated Multi-Beam Additive Manufacturing, Rachel Elizabeth Evans

Browse all Theses and Dissertations

In additive manufacturing (AM), it is necessary to know the influence of processing parameters in order to have better control over the microstructure and mechanical performance of the part. Laser powder bed fusion (LPBF) is a metal AM process in which thin layers of powdered material are selectively melted to create a three-dimensional structure. This manufacturing process is beneficial for many reasons; however, it is limited by the thermal solidification conditions achievable in the available processing parameter ranges for single-beam processing methods. Therefore, this work investigates the effect of multiple, coordinated heat sources, which are used to strategically modify the …

Designing New Generations Of Bcc Lattice Structures And Developing Scaling Laws To Predict Compressive Mechanical Characteristics And Geometrical Parameters, Hasanain Abdulhadi

Browse all Theses and Dissertations

Lattice structures (LSs) have been exploited for wide range applications including mechanical, thermal, and biomedical structures because of their unique attributes combining the light weight and relatively high mechanical properties. The first goal of this research is to investigate the effect of strut orientation and length on the compressive mechanical characteristics of body centered cubic (BCC) LS subjected to a quasi-static axial compressive loading using finite element analyses (FEA). In this study, two lattice generations were built and analyzed in commercial finite element (FE) software, ABAQUS/CAE 2016 using “smart procedure”, a meshing technique which was developed for this research to …

The Thermal And Mechanical Characteristics Of Lithiated Peo Lagp Composite Electrolytes, Jacob Michael Denney

Browse all Theses and Dissertations

Lithium-ion batteries are part of a multibillion-dollar industry that strives to meet the demands for an increasingly advanced technological future. Flexible batteries can be easily adapted from emerging novel wearable electronics to electrical vehicles and advanced solar panels. Solid-state batteries can greatly reduce the risk of fire or leaking hazardous materials due to puncture. For the development of solid-state flexible lithium based batteries polymer-ceramic composites are attractive electrolyte candidates because of their combined properties, such as electrical, thermal and mechanical properties, that not only overcome limitations from the base materials but may also render some enhanced performances resulting from the …

Primary Processing Parameters And Their Influence On Porosity And Fatigue Life Of Additively Manufactured Alloy 718, Luke C. Sheridan

Browse all Theses and Dissertations

In many structural applications void-like defects cause significant performance debits which call for component redesign or post-processing to account for or remove the defects. For laser powder bed fusion (LPBF) processes, it has been shown that many of these features and their size and shape characteristics are controllable through LPBF process parameter manipulation. For design efforts, however, it is necessary to understand the direct influences of processing on the formation of porosity and the role that individual pores and porosity distributions have on the properties and performance of AM components. Additionally, design criteria must be established to facilitate implementation of …

Defect Modeling And Vibration-Based Bending Fatigue Of Additively Manufactured Inconel 718, Wesley Earl Eldt

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Additive manufacturing (AM) is convenient for building components with complex features. However, the long-term integrity of these components is uncertain, since AM parts have defects such as pores and rough surfaces. In this work, an analytical model was developed to determine the impact of defects, and a novel bending fatigue test was used to determine the fatigue life of channeled specimens. The analytical model, based off the theory of critical distances, investigates coupled pores and predicts their potential for fatigue failure. This resulted in a maximum allowable pore size and spacing recommendation for coupled defects. Additionally, specimens with through channels …

Optimization Study Of A Combined Wind-Solar Farm For A Specified Demand, Venkat Siddhartha Rama

Browse all Theses and Dissertations

At the present time, using wind and solar energy for producing electricity in the United States is becoming cost competitive. According to Lazard’s 2019 [36] levelized cost of energy (LCOE) analysis of a number of energy sources used for producing electricity in the United States, wind and solar are cheaper than natural gas and coal. While capital, maintenance, operation, and fuel costs are included in LCOE numbers, energy source intermittency is not. Intermittency is an important issue with wind and solar energy sources, but not with natural gas or coal energy sources. Combining wind and solar energy sources into one …

Additive Manufacturing Techniques To Enhance The Performance Of Electronics Created On Flexible And Rigid Substrates, Aamir Hamed Hamad

Browse all Theses and Dissertations

Different additive manufacturing (AM) methods including fused deposition modeling (FDM) and piezoelectrical drop on demand (DOD) inkjet printing have been used in printed electronics for easy production, easy integration, better performance, and low cost. These methods have been used in producing everyday smart printed electronics such as conformal antennas (planner and non-planar antennas), sensors, actuators, and solar cells created on flexible and rigid substrates. The performance of printed electronics strongly depends on printing techniques and printing resolution that enhance their electrical and mechanical properties. In this dissertation, 3D and surface printing techniques were used to enhance the performance of printed …

Adaptive Multi-Fidelity Modeling For Efficient Design Exploration Under Uncertainty, Atticus J. Beachy

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This thesis work introduces a novel multi-fidelity modeling framework, which is designed to address the practical challenges encountered in Aerospace vehicle design when 1) multiple low-fidelity models exist, 2) each low-fidelity model may only be correlated with the high-fidelity model in part of the design domain, and 3) models may contain noise or uncertainty. The proposed approach approximates a high-fidelity model by consolidating multiple low-fidelity models using the localized Galerkin formulation. Also, two adaptive sampling methods are developed to efficiently construct an accurate model. The first acquisition formulation, expected effectiveness, searches for the global optimum and is useful for modeling …

Correlating In-Situ Monitoring Data With Internal Defects In Laser Powder Bed Fusion Additive Manufacturing, Andrew J. Harvey

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The presence of defects within laser powder bed fusion (LPBF) parts can lead to reduced mechanical properties and life of components. Because of this, the ability to detect these defects within the parts is critical before the part is subject to its intended loading. Normally the parts are subjected to a quality analysis once they are completed however, this process is typically expensive and time consuming. A solution for these problems is to sense the creation of defects and pores in the parts in-situ, while the part is being fabricated. One proposed method of in-situ monitoring is visible spectroscopy to …

Developing Equivalent Solid Model For Lattice Cell Structure Using Numerical Approaches, Tahseen Abdulridha Ali Al-Wattar

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Lattice cell structures (LCS) are the engineered porous structures that are composed of periodic unit cells in three dimensions. Such structures have many scientific and engineering applications, such as in vessel gas technology, thermal systems, mechanical and aerospace structures, etc. for which lightweight, high strength, and energy absorption capabilities are essential properties. To have an optimized design, finite element analysis (FEA) based computational approach can be used for detailed analysis of such structures, sometime in full scale. However, developing a large-scale model for a lattice-based structure is computationally expensive. If an equivalent solid FE model can be developed using the …

Turbine Passage Vortex Response To Upstream Periodic Disturbances, Mitchell Lee Scott

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Flow through the turbine section of gas turbine engines is inherently unsteady due to a variety of factors, such as the relative motion of rotors and stators. In low pressure turbines, periodic wake passing has been shown to impact boundary layer separation, blade surface pressure distribution, and loss generation. The effect of periodic disturbances on the endwall flow is less understood. Endwall flow in a low-pressure turbine occurs in the boundary layer region of the flow through the blade passage where the blade attaches to the hub in the turbine. The response of an endwall vortical structure, the passage vortex, …

Failure Of High Strength Concrete Under Dynamic Uniaxial Compression, Colin Loeffler

Mechanical Engineering Research Theses and Dissertations

The failure strength of concrete materials has been widely shown to be dependent on experimental parameters such as specimen geometry and strain-rate. The effects of specimen geometry have been shown both theoretically and experimentally to be a result of the quasi-brittle nature of concrete. While the failure strength of concrete has been widely reported to increase significantly when deformed at high strain-rates, the physical mechanisms driving this phenomenon remain the source of debate amongst researchers. This means that constitutive models designed to predict this rate dependent behavior are not based on the real physical mechanisms that drive this behavior but …

College Of Engineering Welcomes New Academic Advisor | College Of Engineering, Utah State University

College of Engineering News

USU’s College of Engineering welcomes new academic advisor Valerie Daines. She will provide advising services to mechanical engineering students with last names A through J.

College Of Engineering Welcomes New Academic Advisor | College Of Engineering, Utah State University

College of Engineering News

USU’s College of Engineering welcomes new academic advisor Sierra Browning. She will provide advising services to mechanical engineering students with last names K through Z.

Development Of A Robotized Laser Directed Energy Deposition System And Process Challenges, Meysam Akbari

Mechanical Engineering Research Theses and Dissertations

Metal additive manufacturing (AM) is a disruptive technology, enabling fabrication of complex and near net shaped parts by adding material in a layer-wise fashion. It offers reduced lead production time, decreased buy-to-fly ratio, and repair and remanufacturing of high value components. AM processes are finding applications in many industrial sectors such as aerospace, automotive, biomedical and mold tooling. However, beside tremendous advantages of AM, there are still some challenges that prevent the adoption of this technology into high standard applications. Anisotropy and inhomogeneity in mechanical properties of the as-built parts and existence of pores and lack-of-fusion defects are considered as …

Graphene-Based Water Desalination Using Atomistic Simulations, Thanh Chinh Nguyen

Mechanical Engineering Research Theses and Dissertations

My research focused on investigating saltwater transport through nanoporous graphene membranes using molecular dynamics (MD) simulations. Particularly, in this dissertation, we focused on pressure-driven flows of salt water through uncharged and charged nanoporous graphene membranes for water desalination applications. In the first study, desalination performance of uncharged single-layer nanoporous graphene membranes was observed based on volumetric flow rate, required pressure drop, and salt rejection efficiency. A functional relationship between the volumetric flow rate, pressure drop, pore diameter, and the dynamic viscosity of saltwater was also examined. In further studies, transport of salt ions through positively and negatively charged single-layer nanoporous …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Undergraduate Researcher Awarded at Georgia Environmental Conference

Investigation Of The Electrode Polarization Effect For Biosensor Applications, Anil Koklu

Mechanical Engineering Research Theses and Dissertations

My research focuses on electrokinetic transport. Particularly, in this dissertation, we focus on fabrication and testing of micro electrodes with nanostructured surfaces to minimize the electrode polarization (EP) effects for biosensor applications. In the first study, electrochemical deposition of gold nanoparticles on to planar gold electrodes was used to generate rough surfaces. Dendritic nanostructures that reduced EP up to two orders of magnitude was obtained by optimizing the deposition conditions. These structures also enhanced dielectrophoresis (DEP) response of our bio-chips, making them usable in physiological buffers. In further studies we discovered a universal scaling of EP in the frequency domain, …