Engineering Commons^™

Effects Of Imu Sensor Location And Number On The Validity Of Vertical Acceleration Time-Series Data In Countermovement Jumping, Dianne Althouse

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

Many devices are available for measuring the height of a CMJ. An inertial measurement unit (IMU) measures linear acceleration, orientation, and angular velocity. As an alternative to using IMU estimates of flight time, CMJ height could be estimated by integrating the IMU time-series signal for vertical acceleration to derive CMJ take-off velocity in order to track whole-body center of mass (WBCoM) movement, yet this approach would require valid IMU acceleration data. Thus, the purpose of this study was to quantify the effects of IMU sensor location and number on the validity of vertical acceleration estimation in CMJ. Thirty young adults …

Multi-Sensor Signatures From Ultrasonic Wire Embedding Used In Hybrid Additive Manufacturing, Patrick Steven Gutierrez

Open Access Theses & Dissertations

Additive Manufacturing (AM) has matured such that its products are used in applications ranging from prototypes to end-use parts; however, to expand the adoption of AM, the inclusion of multiple manufacturing technologies has become a focus area especially when the result is a 3D printed part with an embedded electrical system. The W.M. Keck Center for 3D Innovation has developed the Foundry Multi3D system consisting of two material extrusion AM machines, a robotic arm, and a CNC machine equipped with a laser soldering tool, solder micro-dispensing tool and an ultrasonic wire embedding (USWE) tool. The focus of this paper is …

Characterization Of A Flex-Fuel Oxy-Combustion System Through Experimental Investigation And Computational Modeling, Md Mohieminul I. Khan

Open Access Theses & Dissertations

Oxy-fuel combustion has the potential to offer high thermal efficiency and lower pollutants emission compared to other existing combustion technologies. More than 63% of the worldâ??s electricity is produced by fossil fuel combustion which also is the major reason for greenhouse gas emissions. Oxy combustion offers a solution to it. Oxy combustion uses pure oxygen as an oxidizer instead of air which eliminates the NOx and SOx products from the exhaust. In oxy-combustion flue gas mainly consists of CO2 and water vapor. Furthermore, combustion in presence of pure oxygen results in higher flame temperature and hence promises higher thermal efficiency. …

Optimization Of Lattice Structure Using Machine Learning Approach, Tanzila Bint Minhaj

Open Access Theses & Dissertations

The goal line of designing any structure is to get maximum performance at minimum cost. Therefore, optimization is the only method to achieve that objective. Engineers have been practicing different formats of optimization. Topological optimization is one of the well-known long-practiced methods. But it is always desired to find the most helpful design method that considers every relevant parameter associated with the structure. In the continuation of this search to enhance the efficacy of design through optimization, a new approach was explored in the following work. The motivation was to enable a model to be capable of finding out the …

Characterization Of 3d Printed Parts Containing Integrated Functionality Via Ultrasonically Embedded Wires, David Abraham Sepulveda

Open Access Theses & Dissertations

Material extrusion additive manufacturing has been widely adopted because it offers freedom of design, which allows complex geometry fabrication, and rapid prototyping. Interest in producing components with integrated functionality allowed forms of hybrid manufacturing to be developed such as the Multi3D system. This system produces parts with embedded components by combining additive, subtractive, soldering, dispensing, and embedding techniques. However, this involves pausing the printing process (which takes place in a controlled environment) and exposing it to ambient temperature where embedding takes places. In this research, the effect of embedding parts with 24 AWG copper for improved functionality was quantified mechanically. …

Novel Patterning Techniques To Improve Digital Image Correlation In Challenging Environments, Weston Craig

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A camera-based measurement technique called digital image correlation (DIC) is beneficial to measure displacement and strain in challenging environments (such as post-irradiation evaluation and high temperature environments) due to its non-contacting nature and ability to obtain measurements over multiple length scales. This technique requires a surface pattern which influences the measurement resolution and accuracy of the measurements. This thesis explores two novel patterning techniques to allow the use of DIC in more challenging environments:

The first is to determine if a pattern created from printed text can be used as a pattern in DIC. Native patterns are patterns already present …

Speed Of Small Droplets On Repellent Surfaces, Addison J. Litton

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A droplet of fluid can slide or roll down an angled surface if the droplet doesn’t stick to the plate (e.g., droplets on glass). The most common surface to allow for such this motion are hydrophobic surfaces. One example is a freshly waxed car where the rain beads up and rolls off. Another example is if a pan is heated to a high enough temperature then when small amounts of water are added the droplet will skitter around on the surface for a moment before boiling away. This high temperature effect where droplets rest on a vapor layer underneath cause …

Multidisciplinary Reference Solutions For Performance-Optimized Aircraft Wings With Tailored Aerodynamic Load Distributions, Jeffrey D. Taylor

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

Morphing wings, or wings that can change shape during flight, have the potential to substantially reduce the amount of fuel consumed by an aircraft over the course of its flight. However, the extent to which these wings can reduce fuel consumption depends on the design of the wing, including its aerodynamic efficiency and its structural layout, and how the aircraft flies, including its flight altitude and speed. Correctly predicting how these design and operational characteristics interact is critical to predicting how wing morphing may affect aircraft fuel consumption. Many computer prediction tools exist that include the effects of these interactions, …

Manufacturing And Characterization Of Continuous Nanofiber-Reinforced Composites, Lucas Barry

Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research

Fiber-reinforced composite laminates are some of the most advanced structural materials available. However, delamination remains a critical challenge due to its prevalence in structures and ability to cause catastrophic failure. Recently, high-temperature composites are at the forefront of polymer-matrix composites research, but they are prone to microcracking followed by delamination. Nanoreinforcement of interfaces by continuous nanofibers has been proposed earlier at UNL and produced increased interlaminar fracture resistance in conventional advanced composites. However, no studies have yet been conducted on emerging high-temperature composites. Also, there is insufficient information on the translatability of observed modes I and II interlaminar fracture toughness …

Direct Numerical Simulation Of Supercritical Co2 Mixing And Combustion, Syed Mohammad Ovais

All Dissertations

The supercritical CO₂ power cycle (sCO₂ ) is a relatively new technology, which promises to reduce CO₂ emissions with potentially higher efficiencies. However due to challenging conditions posed by supercritical pressures, the mixing and ignition phenomena in sCO₂ combustion is relatively less understood and studied. The primary objective of the current study is to investigate these fundamental processes using homogeneous ignition calculations (HMI) and direct numerical simulations (DNS). Broadly, the study is divided into two major parts. In the first part supercritical mixing in sCO₂ relevant conditions is investigated. To achieve this, DNS of temporally …

Development Of A Reverse Engineered, Parameterized, And Structurally Validated Computational Model To Identify Design Parameters That Influence American Football Faceguard Performance, William Ferriell

All Dissertations

Traumatic brain injury (TBI) continues to have the greatest incidence among athletes participating in American football. The headgear design research community has focused on developing accurate computational and experimental analysis techniques to better assess the ability of headgear technology to attenuate impacts and protect athletes from TBI. Despite efforts to innovate the headgear system, minimal progress has been made to innovate the faceguard. Although the faceguard is not the primary component of the headgear system that contributes to impact attenuation, faceguard performance metrics, such as weight, structural stiffness, and visual field occlusions, have been linked to athlete safety. To improve …

A Modification To The Skiving Process For The Manufacture Of Offset Geometry Strip-Fin Heat Sinks, Daniel Luberda

McKelvey School of Engineering Graduate Student Theses & Dissertations

High-powered electronics are extremely prevalent, and a vast majority of these devices use some form of heat sinks as either an active or passive cooling device. Although two-phase cooling technology has rapidly advanced to accommodate increasing heat loads on modern electronics, the added costs and complication inherent in two-phase cooling solutions makes effective air-cooled heat sinks potentially valuable.

A more effective heat sink can occupy a smaller footprint to dissipate the same heat flux, meaning material and packaging costs can be reduced. Aluminum heat sinks are produced through a variety of manufacturing processes, including machining, bonding, extrusion, casting, forging, 3D …

Foundations For Finite-State Modelling Of A Two-Dimensional Airfoil That Reverses Direction, Jake Michael Oscar Welsh

McKelvey School of Engineering Graduate Student Theses & Dissertations

Current 3-D finite-state wake models are incapable of simulating a maneuver in which the sign of the free-stream velocity changes direction and the rotor enters its own wake -- as might occur in the case of a helicopter which ascends and then descends. It is the purpose of this work to create a 2-D finite-state wake model which is capable of handling changes in free-stream direction as a precursor to development of a 3-D model that can do the same.

The 2-D finite-state model used for reentry modifications is an existing model created by Peters, Johnson, and Karunamoorthy. By the …

Peridynamic Modeling Of Crack Propagation In Brittle Materials With Electromechanical Coupling, Semsi Coskun

Dissertations

The bond-based peridynamics (BB-PD) is a widely used peridynamic model in the literature. Despite Poisson's ratio restriction, it still serves as a powerful tool to solve challenging engineering problems with a relatively cheap computational cost. Consider the Poisson ratio of the material does not deviate from the ones that BB-PD can model. In that case, it becomes advantageous to use the BB-PD compared to other PD models in terms of computational cost and simplicity. However, the BB-PD suffers from the so-called surface or skin effect where the material response at boundaries becomes softer than the bulk material points. As a …

Development Of A Bootcamp For Freshman Student Success During Covid-19 Transition, Eleazar Marquez, Noe Vargas Hernandez, Arturo A. Fuentes

Mechanical Engineering Faculty Publications

Results from assessment show that passing rates in introductory courses as well as retention rates of first-year students in the College of Engineering and Computer Science at a HSI significantly dropped with the advent of COVID-19. Such results and trends provide an overall perspective on the academic preparation of incoming students. There is a high concern that the necessary skill set (e.g., adaptability, persistence, and performance) of the new cohort of students, who are primarily underrepresented Hispanics from underserved and challenged communities from the Rio Grande Valley, is not optimal for the rigor of engineering education. To this end, an …

A Comparison Of Uniaxial Compressive Response And Inelastic Deformation Mechanisms In Freeze Cast Alumina-Epoxy Composites Without And With Rigid Confinement, Tareq Aljuhari

Mechanical & Aerospace Engineering Theses & Dissertations

Cellular ceramics have an array of improved mechanical properties that make them incredibly desired for different applications such as armor systems, aircraft structures, automobiles bumpers, and biomedical implants. It is also desirable that porous architecture could be shaped into bulk complicated shapes and easy to scale-up with low manufacturing cost. Despite several efficient techniques to fabricate cellular ceramics, some limitations are preventing us from meeting the high demand of the after mentioned applications. For that, freeze casting, also called ice-templating, is technique of solidifying an aqueous ceramic suspension under the effect of unidirectional temperature gradient. In this study, Ice-templated porous …

The Effect Of Soft Tissue And Bone Morphology On The Stresses In The Foot And Ankle, Jinhyuk Kim

Mechanical & Aerospace Engineering Theses & Dissertations

The foot and ankle interface with the ground, thus they absorb reaction forces and initiate load distribution through the body. The plantar fascia (PF) is a flexible structure that absorbs reaction forces and distributes loading across the foot. It is frequently a source of foot pain especially when people have plantar fasciitis and/or diabetes mellitus. Finite element (FE) models of the foot and ankle were created to examine the function however, the plantar fascia is frequently modeled as a 1D tension only spring, which does not represent variations caused by injury and/or disease.

As models move toward being patient specific, …

Role Of Structural Hierarchy In Multiscale Material Systems, Siavash Sattar

Mechanical & Aerospace Engineering Theses & Dissertations

Multiscale material systems derive their effective mechanical properties through a hierarchical organization of their structural elements and components. The hierarchy of a material is related to its effective properties, material processing, and composition. The hierarchy can be defined as an identifiable structural component with a specific size scale, such as the individual fibers collimated into platelets arranged randomly and producing a complex composite system or the lamellar structure in freeze-casted ceramic with the variation of in-plane orientation. In this study, the role of the structural hierarchy on the effective mechanical response and failure behavior of three complex material systems was …

Optimization Of Solar-Coal Hybridization For Low Solar Augmentation, Aaron T. Bame, Joseph Furner, Ian Hoag, Kasra Mohammadi, Kody Powell, Brian D. Iverson

Faculty Publications

This work presents a process to determine the preliminary optimal configuration of a concentrating solar power-coal hybrid power plant with low solar augmentation, and is demonstrated on a regenerative steam Rankine cycle coal power plant in Castle Dale, UT, USA (average DNI of 542 W m⁻²). A representative plant model is developed and validated against published data for a coal power plant. The simplifications that lead to the representative model from a coal power plant model include combining multiple feedwater heaters, combining turbines, and using a mass-average calculation for extraction steam properties. Comparing net power generation and boiler …

Collaborative Robotics Strategies For Handling Non-Repetitive Micro-Drilling Tasks Characterized By Low Structural Mechanical Impedance, Xiangyu Wang

Mechanical & Aerospace Engineering Theses & Dissertations

Mechanical micro-drilling finds widespread use in diverse applications ranging from advanced manufacturing to medical surgery. This dissertation aims to develop techniques that allow programming of robots to perform effective micro-drilling tasks. Accomplishing this goal is faced with several challenges. Micro-drills suffer from frequent breakage caused from variations in drill process parameters. Micro-drilling tasks afford extremely low feed rates and almost zero tolerance for any feed rate variations. The accompanying robot programming task is made difficult as mathematical models that capture the micro-drilling process complexities and sensitive variations in micro-drill parameters are highly difficult to obtain. Therefore, an experimental approach is …

Analytical Investigation Of Sound Radiation From Functionally Graded Thin Plates Based On Elemental Radiator Approach And Physical Neutral Surface, B. N. Singh, R. N. Hota, S. Dwivedi, Ratneshwar Jha, V. Ranjan, K. Řehák

Henry M. Rowan College of Engineering Departmental Research

This paper analyzes the sound radiation behavior of a clamped thin, functionally graded material plate using the classical plate theory and Rayleigh Integral with the elemental radiator approach. The material properties of the plate are assumed to vary according to the power-law distribution of the constituent materials in the transverse direction. The functionally graded material is modeled using a physical neutral surface instead of a geometric middle surface. The effects of the power-law index, elastic modulus ratio, different constituent materials, and damping loss factor on the sound radiation of functionally graded plate are analyzed. It was found that, for the …

Passive Prosthetic Ankle Design Based On Indonesian Anthropometry, Wahyu Dwi Lestari

Journal of Mechanical Engineering Science and Technology (JMEST)

Foot prosthesis is a replacement for the foot to overcome activity limitations due to disease, birth defects, accidents, or amputations. Many foot prosthetics have been developed in recent years to treat patients. However, prostheses on the market today have drawbacks, including their high price, lack of comfort, stiff ankles, and low durability. The main objective of this study is to develop an existing ankle-foot prosthesis design that approximates the resemblance of a human foot according to the anthropometry of Asians, especially Indonesians. This study contains the design of a prosthetic foot with a skin design model and a support core. …

Effect Of Variation Of Sic Mass Fraction On Mechanical Properties Of Al-Sic Composite Using Stir Casting Method, Sumarji Sumarji, Naufal Fardio Albajili, Mahros Darsin, Rahma Rei Sakura, Andi Sanata

Journal of Mechanical Engineering Science and Technology (JMEST)

Al-SiC is a composite composed of AA6061 as a matrix and SiC as a reinforcement particle. The variation of mass added will affect the mechanical properties of the composite because Al-SiC is hardenable, which means that its mechanical properties can be improved by adding the reinforcement component. However, an excessive portion of SiC leads to a decrease in mechanical properties. The purpose of this study was to find the optimal composition of the addition of SiC into the aluminium matrix to gain maximum tensile strength and hardness. The mass fraction variation that would be used in this composite was the …

Effect Of Homogenization Pressure On Bacterial Cellulose Membrane Characteristic Made From Pineapple Peel Waste, Muhamad Muhajir, Heru Suryanto, Yanuar Rohmat Aji Pradana, Uun Yanuhar

Journal of Mechanical Engineering Science and Technology (JMEST)

Many studies were conducted to maintain the environment by reducing the waste, especially pineapple peel waste. This study aims to explore the effect of various pressure of the homogenization process on bacterial cellulose membrane surface morphology and structure produced using extract of pineapple peel waste. The methods include the preparation of pellicle samples from the product of the fermentation process of Acetobacter xylinum using a medium from the extract of pineapple peel waste. Bacterial cellulose pellicles were crushed using a blender. Mashed bacterial cellulose pellicle was homogenized in High-Pressure Homogenizer with pressure variation of 150 bar, 300 bar, 450 bar, …

Machine Vision For The Various Road Surface Type Classification Based On Texture Feature, Susi Marianingsih, Widodo Widodo, Marla Sheilamita S. Pieter, Evanita Veronica Manullang, Hendry Y. Nanlohy

Journal of Mechanical Engineering Science and Technology (JMEST)

The mechanized ability to specify the way surface type is a piece of key enlightenment for autonomous transportation machine navigation like wheelchairs and smart cars. In the present work, the extracted features from the object are getting based on structure and surface evidence using Gray Level Co-occurrence Matrix (GLCM). Furthermore, K-Nearest Neighbor (K-NN) Classifier was built to classify the road surface image into three classes, asphalt, gravel, and pavement. A comparison of KNN and Naïve Bayes (NB) was used in present study. We have constructed a road image dataset of 450 samples from real-world road images in the asphalt, gravel, …

Gasohol Engine Performance With Various Ignition Timing, Hendry Y. Nanlohy, Suyatno Suyatno, Helen Riupassa, Marthina Mini, Trismawati Trismawati, Mebin Panithasan

Journal of Mechanical Engineering Science and Technology (JMEST)

Experimental research has been conducted on the effect of ignition timings on the characteristics and performance of gasohol engines such as power, torque, specific fuel consumption, and thermal efficiency. The fuel used in this research is pure gasoline and a mixture of 50% bioethanol (BE50). The results show that the ignition timing that gives the maximum effect occurs at the top and bottom dead points of 9 degrees for gasoline and 12 degrees for BE50 fuel. Furthermore, the maximum power is obtained at 6,500 rpm, and at an ignition time of 12 degrees BTDC the maximum power generated is 4.63 …

Surface Quality Of Fe, Ni And Cr Added Hyper-Eutectic Al-Si Automotive Alloys Under Up-Milling And Down-Milling Operation, Akib Abdullah Khan, Mashiur Rahman Shoummo, Mohammad Salim Kaiser

Journal of Mechanical Engineering Science and Technology (JMEST)

Effect of the elements Fe, Ni, and Cr on the surface quality under machining of hyper-eutectic aluminiumbased Al-Si automotive alloys has been carried out as the elements improve the properties of this alloy. Machining is done on a horizontal type milling machine using a high-speed steel slab milling cutter in dry condition. Only the cutting speed varies throughout the experiment, while the machining feed and depth of cut remain fixed. The experimental results show that the addition of these alloying elements increases the roughness and hardness specially due to formation of Fe-rich intermetallic ��-����5��������. However, the needle-like ��-����5�������� has been …

Run-To-Run Control Via Constrained Optimization Of A Mechanical Serial-Sectioning System, Damian L. Gallegos-Patterson

Mechanical Engineering ETDs

This thesis develops a methodology for run-to-run (R2R) control of a mechanical serial sectioning (mss) system for microstructural investigations. mss is a destructive material characterization process which repeatedly removes a thin layer of material and images the exposed surface. The images are then used to gain insight into the internal structure and arrangement of a material and are often used to generate a 3-dimensional (3D) reconstruction of the sample. Currently, an experienced human operator selects the parameters for mss to achieve the desired per slice removal rate. The proposed R2R control methodology automates this process while improving the precision and …

An Algorithm For Task Allocation And Planning For A Heterogeneous Multi-Robot System To Minimize The Last Task Completion Time, Abhishek Patil, Jungyun Bae, Myoungkuk Park

Michigan Tech Publications, Part 1

This paper proposes an algorithm that provides operational strategies for multiple heterogeneous mobile robot systems utilized in many real-world applications, such as deliveries, surveillance, search and rescue, monitoring, and transportation. Specifically, the authors focus on developing an algorithm that solves a min-max multiple depot heterogeneous asymmetric traveling salesperson problem (MDHATSP). The algorithm is designed based on a primal-dual technique to operate given multiple heterogeneous robots located at distinctive depots by finding a tour for each robot such that all the given targets are visited by at least one robot while minimizing the last task completion time. Building on existing work, …

Employing Boundary Element Approach With Genetic Algorithm To Increase Travel Range Of Repulsive Actuators, Yu Tian, Ronald N. Miles, Shahrzad Towfighian

Mechanical Engineering Faculty Scholarship

The design of repulsive electrostatic actuators having enlarged travel range is achieved by combining the boundary element approach and a genetic algorithm. The boundary element method enables calculating the electrostatic forces without time consuming finite element simulations. Once a static equation that uses a model of effective lumped mass solves the travel ranges, the GA maximizes travel ranges by optimizing the dimensional parameters. The effectiveness of the scheme is demonstrated with extensive experimental results showing the travel ranges of a micro out-of-plane actuator are increased by up to 190%. The developed platform can improve the signal-to-noise ratios and the performance …