Mechanical Engineering Commons^™

Experimental And Finite Element Studies Of Shock Transmission, Eldon Jerry Goddard

UNLV Theses, Dissertations, Professional Papers, and Capstones

Composite materials are more widely used today in engineering products than ever before. Shock transmission in jointed composite sections needs to be investigated to understand the affect of composite materials on the dynamic response of the system. There exists limited published work on transient shock propagation through composite sections. The aim of this study is to analyze the transient behavior of joints in composite materials subjected to low impact loads and to develop a computational model that provides an improved physics based shock model. The jointed connection will be investigated experimentally and using Finite Element Analysis (FEA). The bolted joint …

Improving Global Impact: How The Integration Of Remotely Reporting Sensors In Water Projects May Demonstrate And Enhance Positive Change, Evan A. Thomas

Mechanical and Materials Engineering Faculty Publications and Presentations

This article argues that improved feedback on the actual impact of development programs may ensure the success of poverty reduction interventions such as water filters, water pumps, latrines, and cookstoves.

Development Of A Hybrid Vehicle Powertrain Test Laboratory, Bennet Samuel Soundarraj

Doctoral Dissertations and Master's Theses

During the last two years, Embry-Riddle Aeronautical University has installed and tested a fully functional eddy-current chassis dynamometer testing facility on campus. An automotive test facility requires a systems engineering approach to install, calibrate and commission a chassis dynamometer. This thesis shows that, the dynamometer test facility was successfully installed, commissioned and documented to safely support the power train development and testing. We can currently test the EcoCAR vehicle and a number of other front-wheel-drive vehicles at our university campus using the eddy current chassis dynamometer.

Pvcrov : An Experimental Platform For Multi-Robot Control Systems, Nicholas Prince, Gregory Roos, Jennifer Semones, Chase Traficanti

Mechanical Engineering Senior Theses

As the field of multi-robot control systems grows, the demand for flexible, robust and precise multi-robot testbeds increases. Up to this point, the testbeds that do exist for testing multi-robot controllers are often expensive, hard to deploy, and typically constrained to a single plane of motion. These constraints limit the capacity to conduct research which is why team Autonomously Controlled Electromechanical Systems (ACES) has created the PVCROV system. PVCROV is a low cost, underwater platform for testing multi-robot control systems. By utilizing an underwater environment, ACES created a testbed that is not constrained to a single plane of motion. Additionally, …

Liquid Phase Stability Under An Extreme Temperature Gradient, Zhi Liang, Kiran Sasikumar, Pawel Keblinski

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Using Nonequilibrium Molecular Dynamics Simulations, We Subject Bulk Liquid to a Very High-Temperature Gradient and Observe a Stable Liquid Phase with a Local Temperature Well above the Boiling Point. Also, under This High-Temperature Gradient, the Vapor Phase Exhibits Condensation into a Liquid at a Temperature Higher Than the Saturation Temperature, Indicating that the Observed Liquid Stability is Not Caused by Nucleation Barrier Kinetics. We Show that, Assuming Local Thermal Equilibrium, the Phase Change Can Be Understood from the Thermodynamic Analysis. the Observed Elevation of the Boiling Point is Associated with the Interplay between the "Bulk" Driving Force for the Phase …

Investigation Of Thermal Cycle And Hardness Distribution In The Laser Cladding Of Aisi H13 Tool Steel Produced By A High Power Direct Diode Laser, Parisa Farahmand, Prabu Balu, Fanrong Kong, Radovan Kovacevic

Mechanical Engineering Research

Laser cladding (LC) of tool steel has significant application in rapid tooling, and surface coating for worn-out components in different industries. During the LC process, several phase transformations influence the microstructural and mechanical properties of the deposited layer. In order to successfully implement the LC process, it is essential to understand the relationship between the thermal cycle (heating and cooling), phase transformations, and the output quantities of the deposited layer. In this study a direct diode laser with a power of up to 8 kW was used to deposit AISI H13 tool steel on mild steel grade A36 substrate to …

Mechanical Engineering News, Georgia Southern University

Mechanical Engineering: News & Publications (2013-2023)

• Accepting Applications for National Science Foundation: Research Experience for Undergraduates

Ergonomichandle And Articulating Laparoscopictool, M. Susan Hallbeck, Dmitry Oleynikov, Kathryn Done, Tim Judkins, Allison Dimartino, Jonathan Morse, Lawton N. Verner

Department of Mechanical and Materials Engineering: Faculty Publications

The present invention relates to a laparoscopic apparatus. The apparatus includes a handle having a body portion, a top surface, opposite bottom surface, a proximal and distal end. The top surface of the base is contoured to compliment the natural curve of the palm. The apparatus further includes a shaft projecting from the distal end of the handle. The shaft has a proximal and distal end. A control sphere is located on the handle. The control sphere can be moved by one or more of a user's fingers to indicate direction. An end effector is located at the distal end …

Wax Pattern Shrinkage Project Summary, David Bishop, Perry Carter

Journal of Undergraduate Research

Purpose: The purpose of this project was to better understand the sources of variation that influence the shrinkage of wax patterns in investment casting. With a better understanding of the variation, manufacturers will be able to produce parts that have more precise dimensions.

Cad Tools For Thermal Growth Research, C. Porter Bassett, Dr. C. Greg Jensen

Journal of Undergraduate Research

For my project I developed two tools to aid in manufacturing research that is currently being conducted in the Mechanical Engineering Department. This research is about milling, a type of manufacturing where metal is machined bye a spinning cutting tool, very similar to a drill bit, that cuts away the metal. This process generates a lot of heat and causes the cutting tool to heat up. When it heats up, it also expands and changes shape. The change in size of the cutting tool effects how much metal it removes. In precision work, this change in shape can be enough …

Strain In Polysilicon Microbeams: The Relationship Between Beam Geometry And The Nominal Strain At Failure, Susan Norma, Candland Bromley, Dr. Larry L. Howell

Journal of Undergraduate Research

The objective of this research was to investigate the stress and strain behavior of microscopic cantilevered polycrystallin silicon (polysilicon) beams. A knowledge of this behavior is necessary to accomplish reliable mechanical design of micro-electro-mechanical systems (MEMS).

Oil Droplet Behavior At A Pore Entrance In The Presence Of Crossflow: Implications For Microfiltration Of Oil-Water Dispersions, Nikolai V. Priezjev, Tohid Darvishzadeh, Volodymyr V. Taravara

Mechanical and Materials Engineering Faculty Publications

The behavior of an oil droplet pinned at the entrance of a micropore and subject to clossflow-induced shear is investigated numerically by solving the Navier-Stokes equation. We found that in the absence of crossflow, the critical transmembrane pressure required to force the droplet into the pore is in excellent agreement with a theoretical prediction based on the Young-Laplace equation. With increasing shear rate, the critical pressure of permeation increases, and at sufficiently high shear rates the oil droplet breaks up into two segments. The results of numerical simulations indicate that droplet breakup at the pore entrance is facilitated at lower …

Simulation Of Vertical Axis Wind Turbines With Variable Pitch Foils, L. Damon Woods, John F. Gardner, Kurt S. Myers

Mechanical and Biomedical Engineering Faculty Publications and Presentations

A dynamic computer model of a turbine was developed in MATLAB in order to study the behavior of vertical axis wind turbines (VAWTs) with variable pitch (articulating) foils. The simulation results corroborated the findings of several empirical studies on VAWTs. The model was used to analyze theories of pitch articulation and to inform the discussion on turbine design. Simulations of various models showed that pitch articulation allowed Darrieus-style vertical axis wind turbines to start from rest. Once in motion, the rotor was found to accelerate rapidly to very high rotational velocities. The simulations revealed a plateau region of high efficiency …

Developing An Architecture Framework For Cloud-Based, Multi-User, Finite Element Pre-Processing, Jared Calvin Briggs

Theses and Dissertations

This research proposes an architecture for a cloud-based, multi-user FEA pre-processing system, where multiple engineers can access and operate on the same model in a parallel environment. A prototype is discussed and tested, the results of which show that a multi-user preprocessor, where all computing is done on a central server that is hosted on a high performance system, provides significant benefits to the analysis team. These benefits include a shortened preprocessing time, and potentially higher-quality models.

An Investigation Into The Mechanisms Of Formation Of The Hard Zone In Fsw X65, Jacob D. Allred

Theses and Dissertations

Friction stir welding (FSW) of HSLA steel commonly produces a hard zone (HZ) on the advancing side (AS) of the weld. Despite its detrimental effects on weld toughness, the mechanisms of its formation have not been thoroughly investigated and are not well understood. This paper investigates the various mechanisms in FSW believed to affect the weld HZ, namely: strain, strain-rate, peak temperature and cooling rate. Gleeble tests indicate that strain and strain rate have negligible effects on weld HZ with cooling rate and peak temperature as dominant effects. Jominy tests resulted in cooling rate having 270% greater influence than peak …

Artificial Intelligent Metallurgical Grain Detection, Adarsh Kesireddy

Mechanical Engineering Theses

In recent years, image processing has been applied to metallurgy but its applications were mainly confined to iron. This research instead focuses on recognizing phases present in steel. Phase recognition is very important because it aids in specifying the properties of steel specimens. This research is concentrated on recognizing Pearlite, Ferrite, Martensite and Cementite present in steel. A neural network was used to recognize these four phases. For a neural network to recognize any object it requires input values called features. This research introduces a combination of features which were not used before: texture based features of entropy, energy, contrast, …

Trajectory Generation And Optimization For Experimental Investigation Of Flapping Flight, Michael Schnebly Wilcox

Theses and Dissertations

Though still in relative infancy, the field of flapping flight has potential to have a far-reaching impact on human life. Nature presents a myriad of examples of successful uses of this locomotion. Human efforts in flapping flight have seen substantial improvement in recent times. Wing kinematics are a key aspect of this study. This study summarizes previous wing trajectory generators and presents a new trajectory generation method built upon previous methods. This includes a novel means of commanding unequal half-stroke durations subject to robotic trajectory continuity requirements. Additionally, previous optimization methods are improved upon. Experimental optimization is performed using the …

Energy Analysis & Utility Cost Mitigation With Storage For Commercial Buildings In California, Eric Anthony Fleming

LMU Theses and Dissertations

While on a great precipice of emerging energy technologies, it is necessary to understand how these technologies are most effectively integrated into current end-user systems. At the moment,

36% of California’s energy consumption is demanded from the commercial buildings sector. This report investigates the nature of energy with the state of California through various sources and analysis techniques. Using specific weather and commercial building data, this paper also focuses on the analysis of Commercial Building energy demand modeling for the state’s sixteen weather zones. It is modeled using the Department of Energy’s tool: EnergyPlus and analysis is performed with R …

Mems Fabrication Process Base On Su-8 Masking Layers, Scott A. Ostrow, Ronald A. Coutu Jr.

AFIT Patents

A novel fabrication process uses a combination of negative and positive photoresists with positive tone photomasks, resulting in masking layers suitable for bulk micromachining high-aspect ratio microelectromechanical systems (MEMS) devices. This technique allows the use of positive photomasks with negative resists, opening the door to an ability to create complementary mechanical structures without the fabrication delays and costs associated with having to obtain a negative photomask. In addition, whereas an SU-8 mask would normally be left in place after processing, a technique utilizing a positive photoresist as a release layer has been developed so that the SU-8 masking material can …

Load Path Uncertainty In A Wood Structure And The Effect On Structural Reliability, Wenqi Wang, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The roof truss bearing points of a light-framed wood house were instrumented with load cells. It was found that under dead load alone, symmetric and theoretically identical truss reactions have significant variation. A similar degree of reaction discrepancy was found under the application of uplift pressures caused by hurricane winds. Analysis revealed that the majority of this discrepancy is caused by inherent uncertainties in load path. Although uncertainties in load magnitude and material resistance are accounted for in design by use of appropriate load and resistance factors, load path is generally taken to be deterministic. In this study, load path …