Applied Mechanics Commons^™

Soft-Microrobotics: The Manipulation Of Alginate Artificial Cells, Samuel Sheckman

Mechanical Engineering Research Theses and Dissertations

In this work, the approach to the manipulation of alginate artificial cell soft-microrobots, both individually and in swarms is shown. Fabrication of these artificial cells were completed through centrifugation, producing large volumes of artificial cells, encapsulated with superparamagnetic iron oxide nanoparticles; these artificial cells can be then externally stimulated by an applied magnetic field. The construction of a Permeant Magnet Stage (PMS) was produced to manipulate the artificial cells individually and in swarms. The stage functionalizes the permanent magnet in the 2D xy-plane. Once the PMS was completed, Parallel self-assembly (Object Particle Computation) using swarms of artificial cells in complex …

Blunt And Ballistic Impacts On Human Head Models: An Analytical And Numerical Study, Yongqiang Li

Mechanical Engineering Research Theses and Dissertations

Head injuries, as a leading cause of death, have become a major health care issue for civilians and soldiers. There has been an urgent need to understand mechanisms of such injuries. The objective of this dissertation research is to study some head injuries and related mechanisms using analytical and computational models.

In Chapter 2, a new analytical (non-linear) model for the impact of a solid sphere on a fluid-filled spherical shell is developed by including the stress wave propagation effect in addition to the Hertzian contact deformations and the shell membrane and bending actions. A simplified (linearized) model incorporating the …

Modeling Of Swimming Cells From Nano-Scale To Micro-Scale, Yicheng Zhao

McKelvey School of Engineering Graduate Student Theses & Dissertations

Certain human genetic diseases -- primary ciliary dyskinesia, infertility, and hydrocephalus -- are characterized by changes in beat frequency and waveform of cilia and flagella. Chlamydomonas reinhardtii, which is a single-cell green alga about ten micrometers in diameter that swims with two flagella, serves as an excellent biological model because its flagella share the same structure and genetic background as mammalian cilia and flagella. This study uses the finite element method to investigate the behavior of C. reinhardtii swimming from nano-scale to micro-scale. At the device-level, micro-scale modeling indicates that well-designed acoustic microfluidic devices can be used to trap groups …

Digital Enhancement Of Analog Measurement Systems For Temperature Compensation Of Strain Gages, Islombek Karimov

Electrical Engineering Theses

Generally known temperature compensation techniques for strain gages (like the use of a dummy gage or the implementation of half- and full-bridge configurations) are not applicable to all strain-measurement situations and cannot fully compensate for all sources of error. Digital Enhancement of Analog Measurement Systems presents a universal method of corrections for these effects in which temperature is measured independently of other variables and ex post facto corrections are computed and applied to digitized readings of the analog measurement system.

A single, linear-pattern strain gage, self-temperature-compensated for steel 1018, has been utilized in a quarter-bridge to measure tensile strain in …

Microheater Array Powder Sintering (Maps) For Printing Flexible Electronics, Nicholas Holt

Graduate Theses and Dissertations

Microheater array powder sintering (MAPS) is a novel additive manufacturing process that uses an array of microheaters to selectively sinter powder particles. MAPS shows great promise as a new method of printing flexible electronics by enabling digital curing of conductive inks on a variety of substrates. MAPS operation relies on establishing a precision air gap of a few microns between an array of microheaters, which can reach temperatures of 600°C, and a layer of conductive ink which can be deposited onto a flexible substrate. This system presents challenges, being: the fabrication of a microheater that can reach suitable temperatures in …

A Nanoindentation Study Of The Fatigue Properties Of Al/A-Si Core-Shell Nanostructures, Jason Steck

Mechanical Engineering Undergraduate Honors Theses

Nanostructure-textured surfaces can reduce friction and increase the reliability of micro- and nanoelectromechanical systems (NEMS/MEMS). For MEMS incorporating moving parts, the fatigue properties of nanostructures pose a challenge to their reliability in long-term applications. In this study, the fatigue behavior of hemispherical Al/a-Si core-shell nanostructures (CSNs), bare hemispherical Al nanodots, and a flat Al/a-Si layered thin film have been studied using nanoindentation and nano-scale dynamic mechanical analysis (nano-DMA) techniques. Fatigue testing with nano-DMA shows that the deformation resistance of CSNs persists through 5.0 × 10⁴ loading cycles at estimated contact pressures greater than 15 GPa. When the a-Si shell …

Phase Transitions In Monochalcogenide Monolayers, Mehrshad Mehboudi

Graduate Theses and Dissertations

Since discovery of graphene in 2004 as a truly one-atom-thick material with extraordinary mechanical and electronic properties, researchers successfully predicted and synthesized many other two-dimensional materials such as transition metal dichalcogenides (TMDCs) and monochalcogenide monolayers (MMs). Graphene has a non-degenerate structural ground state that is key to its stability at room temperature. However, group IV monochalcogenides such as monolayers of SnSe, and GeSe have a fourfold degenerate ground state. This degeneracy in ground state can lead to structural instability, disorder, and phase transition in finite temperature. The energy that is required to overcome from one degenerate ground state to another …

A High-Magnification Uv Lens For High-Temperature Optical Strain Measurements, Robert S. Hansen

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

Digital Image Correlation (DIC) is an experimental method used to produce full-field strain maps of specimens undergoing deformation. In this measurement, images of a specimen are taken before and after mechanical and thermal loading, then software is used to track deformation and compute strains. DIC has been recently adapted for high-temperature tests by using ultraviolet (UV) range cameras, lenses, and filters to produce the images.

Application of DIC to small length scales and at high temperatures can be performed with proper equipment. However, for these measurements, there is no commercially available high-magnification lens that will allow images to be taken …

Novelis Teaching Table, Phillip Laplante, Robert Hemker, Taylor Mcgriff, Juan Restrepo, Shelly Abraham

KSU Journey Honors College Capstones and Theses

Novelis is a company that specializes in metal casting, recycling, and rolling. They primarily focus on aluminum rolling for cans and car bodies but are an industry leader in numerous related areas. As the rolling process is not taught in most general engineering courses, Novelis periodically teaches new engineers and technicians about the specifics of this relatively mathematically complex process. Most of the current teaching methods are through PowerPoint presentations and group exercises, with minimal hands-on involvement. One of the most useful tools for teaching the rolling process is an actual jeweler’s rolling mill, which Novelis currently possesses, but is …

Numerical Simulation Of A High Strain Rate Biaxial Compression Apparatus, Michael Lagieski

McKelvey School of Engineering Graduate Student Theses & Dissertations

Few experimental methods today are capable of exploring the strength of materials at high strain rates (10⁵ s^-1). Those that are capable, such as the Split Hopkinson Bar, Taylor Anvil and Plate Impact suffer from instability and are generally limited to one dimensional wave propagation. Of particular interest is material response under biaxial compression, similar to that seen in inertial confinement fusion. Laser fusion fuel pellets typically undergo large strain rates as well as plastic deformation and non-linear behavior. This work briefly outlines an experimental procedure designed to replicate these large strain rates under biaxial compression using …

Rotordynamic Analysis Of Theoretical Models And Experimental Systems, Cameron R. Naugle

Master's Theses

This thesis is intended to provide fundamental information for the construction and

analysis of rotordynamic theoretical models, and their comparison the experimental

systems. Finite Element Method (FEM) is used to construct models using Timoshenko

beam elements with viscous and hysteretic internal damping. Eigenvalues

and eigenvectors of state space equations are used to perform stability analysis, produce

critical speed maps, and visualize mode shapes. Frequency domain analysis

of theoretical models is used to provide Bode diagrams and in experimental data

full spectrum cascade plots. Experimental and theoretical model analyses are used

to optimize the control algorithm for an Active Magnetic Bearing …

Investigation Of Discrete Element Methods For Stud To Turf Interactions, Justin Rittenhouse

Masters Theses

Artificial turf is frequently used in sports today and attempts to advantageously replicate a natural grass/soil playing surface. Despite numerous advantages, the technology is correlated with an increase in injuries. The concept behind this research is to create and validate a discrete element model (DEM) for the ground/foot interaction through the use of open source software. After validation, the goal is to analyze an arrangement of studs to determine what role stud geometry plays on torque [N-mm] and force [N] generation. The validation data was provided through laboratory experiments. Three football studs attached to a rigid bracket were turned at …

Determination Of Chemical Notch, KChem On Aluminum And Steel When Subjected Under Slow Strain Rate Test In Corrosive Environment, Joshua Teo Lee Kuok

Masters Theses

When designing for any mechanical components or system, the question would arise as to how the material would react to the loads subjected on it? Would the component survive its service load? How would it react to environmental corrosion? To answer these questions, the technique used in this thesis paper is the Slow Strain Rate Test (SSRT) method. Aluminum and steel were chosen as the material to be tested in this paper. Al 7075-T651, and Al 6061-T651 was chosen due to its wide range of application, high strength to weight ratio and ease of machinability. It is highly used in …

Experimental Investigation Of A New Spiral Wingtip, Naseeb Ahmed Siddiqui, Mohammed Aldheeb, Waqar Asrar, Erwin Sulaeman

International Journal of Aviation, Aeronautics, and Aerospace

Experiments on the relative merits and demerits of slotted wingtips mimicking a bird’s primary feathers have been performed. The real emargination length of feather tips, their flexibility and curved shapes during cruise are considered in the present study. The experiments were performed at a Reynolds number of 3.7 x 10⁵ on a symmetric flat plate half wing of aspect ratio 3. Lift, drag and pitching moments were measured using a six component aerodynamic balance. Four different shapes inspired by bird primary feathers have been analysed. The rigid curved tip performed the best increasing the L/D ratio by 20%. This …

A 2-D Finite Element Modeling And Simulation Of 3-Roll Forming, Wenbo Zhao

LSU Master's Theses

Medium to large diameter carbon steel pipes are widely used in various applications such as gas and fluid transportation, tunnels construction and building construction. Based on manufacturing techniques and characteristics, they are mainly categorized into three categories: Seamless pipe, Butt-welded pipe and Spiral pipe. The forming of butt-welded and spiral pipe is often performed by a technique called 3-roller bending. While traditional trial-and-error method is costly, the geometry complexity, along with material nonlinearity makes exact theoretical analysis difficult unless heavy simplified assumptions are made. While the forming parameters in the 3-roller forming process of butt-welded pipe has been studied in …

H.F. Hauff Electric Pruner Drive Train, Grady Graff

All Undergraduate Projects

The H.F. Hauff Company invests a large amount of money in developing a quality pruner used in everyday agriculture. Modern electric pruners tend to be expensive while manual tree pruning is very physically demanding. A battery assisted pruner that is light-weight, ergonomic, inexpensive to build and powerful enough to cut branches that a nominal apple tree would possess is the direct affiliation that H.F. Hauff devotes its funding too. A team of engineering students from Central Washington University developed a product with consideration to each of these circumstances. Since hand drills have proven to be user friendly and of abundance …

Exercise Machine Generator, Duane Harbick

All Undergraduate Projects

Exercise “spinning bikes” and bicycle training stands are common ways to maintain fitness and train for cycling. This exercise necessitates the user putting work into the machine by means of pedaling. In many instances the work put into exercise bikes and training stands is not taken advantage of. The objective of this project is an attempt to make use of some of the energy that a person would usually expend during exercise by building a generator that interfaces with multiple spinning bikes and training stands. It uses a synchronous pulley system to interface with the exercise machine and spin a …

Cassette Lockring Removal Tool, Kyle Wright

All Undergraduate Projects

Removal of a bicycle cassette requires additional tools to hold the cassette in place while loosening the cassette lockring. Typically a tool called a chain whip is used to stabilize the cassette, but is difficult to quickly and correctly apply to the cassette. Due to the need for an additional tool to hold the cassette, the user is faced with utilizing both hands while still needing to somehow hold the wheel in place. The lockring is torqued relatively tight and the overall combination of force, ergonomics, and number of tools required makes the task difficult to perform quickly. The objective …

Equibiaxial Flexural Strength Testing Of Advance Ceramics, Ryan T. Jordan

Honors Undergraduate Theses

Ceramics are very important materials with many unique properties used in numerous industrial applications. Ceramics could be very hard and very strong in comparison to metals; however, they are very brittle, thus they are prone to instantaneous and catastrophic failure. Therefore, their reliability is compromised and it is very important to have advanced techniques that allow evaluating their mechanical behavior in many unusual stress states. One of such testing methods is biaxial strength method, that allows to measure properties not only unidirectional, but also in a biaxial way. The research work for this thesis will be built on design and …

Raman Spectroscopy Of The Skeleton Of The Coral Acropora Cervicornis, Zachary C. Shepard

Honors Undergraduate Theses

Coral reefs are an important element of marine ecosystem that are critical to maintain a healthy environment. Unfortunately, in recent years coral reefs are doing poorly and many in parts of the ocean are simply dying. Therefore, study of coral’s structural response to external loads could answer what will happen with their structures, while they exhibit different types of loading. Therefore, the proposition of using in-situ micro-Raman spectroscopy to study skeletons of Acropora cervicornis was used. Coral skeleton samples I subjected to mechanical loading studied their vibrational properties by exciting the material with 532nm visible light. A uniaxial compressive load …