Mechanical Engineering Commons^™

Enhance Diamond Coating Adhesion By Oriented Interlayer Microcracking, Habio Guo, Xingcheng Xiao, Yue Qi, Zhi-Hui Xu, Xiaodong Li

Faculty Publications

In this paper, we report a microcrack toughening mechanism for enhancing the adhesion of diamondcoating. The oriented microcracks were formed within the TiC interlayer to dissipate strain energy and accommodate deformation via the crack opening-closing mechanism, thus enhancing the coating/substrate interfacial toughness. The delamination of diamondcoating was effectively prevented when the parallel microcracks were confined within the interlayer and arrested at interfaces of coating/interlayer/substrate. Density functional theory calculations revealed that the highly anisotropicfracture strength of the TiC phase energetically favors crack initiation and propagation along (100) planes only, which are 54.7° away from the interface. These microcracks are constrained inside …

Formula Sae Interchangeable Independent Rear Suspension Design, Mike Mccune, Daniel Nunes, Mike Patton, Courtney Richardson, Evan Sparer

Mechanical Engineering

The Suspension Solutions design team has completely designed built and tested an independent rear suspension system for the 2008 FSAE car. The car currently features a solid rear axle, and the task of converting it to incorporate an interchangeable rear suspension has been undertaken in order to quantify the advantages and disadvantages of each design philosophy. The car has been properly tested with both the solid axle and independent rear suspension side-by-side, however more testing is suggested. After pushing both setups to their limits on a 50ft diameter skid pad, the test results were quantified, and a final comparison between …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mathematics Faculty Publications

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Hydraulic Hand Press Final Project Report, Nathaniel Marc Brown, Matthew Thomas Knorr

Mechanical Engineering

This report provides a thorough description of the design of a hydraulic hand-operated press by mechanical engineering students at California Polytechnic State University, San Luis Obispo, California, for the Estrella Warbirds Museum in Paso Robles, California. It begins with research into hydraulic operations, a brief study of fluid power and incompressible fluids, and a look into existing products. Specified customer requirements stipulate the loading and general size constraints. As part of the project, a schedule is laid out following industry techniques. Brainstorming and decision matrices are utilized as well, conveying our design process. A basic structure is developed using strength …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Mikhail Khenner

Mikhail Khenner

A mathematical model for the evolution of pulsed laser-irradiated, molten metallic films has been developed using the lubrication theory. The heat transfer problem that incorporates the absorbed heat from a single laser beam or the interfering laser beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the reflectivity, the peak laser beam …

Best-In-Class Global Bumper Reinforcement Beam, Garret Anthony Bautista, Chad Anthony Hardin, Benjamin Ray Taylor

Mechanical Engineering

Modern bumper systems are governed by laws and regulations imposed separately by various countries. Today, the regulations in China, North America, and Europe are becoming more similar, but there is not a widely accepted bumper reinforcement that meets the requirements of all markets around the globe.

A universal bumper reinforcement beam incorporating Plug-n-Play techniques was developed to meet and exceed all testing requirements and performance standards of each country. These Plug-n-Play techniques consist of adding energy absorbing attachments to the front of a base bumper beam. Simple beam analysis and FEA were the primary analysis tools in the development of …

Supermileage Team - Urban Concept Competition Vehicle Chassis Design Report, Andrew Allport, Kevin Braico, Kevin Charles, George Kyi, William Lai

Mechanical Engineering

This research and design project was proposed by the Cal Poly Supermileage team. They have requested for our team to design an Urban Concept car, a new category of vehicles to compete for fuel efficiency in the Shell Eco-marathon in 2010. The primary focus of our team is in the design and construction of a chassis the Supermileage team can use for the 2010 competition in Fontana, CA. This design must meet dimensional and functional requirements set by Shell while being designed to maximize efficiency in the competition.

There were various chassis concepts under consideration that would possibly work for …

October 2009, Tractor Museum

Lester F. Larsen Tractor Museum: Planning and Development Documents

Agenda, minutes, treasurer report, director report, docent report, associate report, activities report, test lab report

Strain Energy And Lateral Friction Force Distributions Of Carbon Nanotubes Manipulated Into Shapes By Atomic Force Microscopy, Mark C. Strus, Roya R. Lahiji, Pablo Ares, Vincente Lopez, Arvind Raman, Ron R. Reifenberger

Other Nanotechnology Publications

The interplay between local mechanical strain energy and lateral frictional forces determines the shape of carbon nanotubes on substrates. In turn, because of its nanometer-size diameter, the shape of a carbon nanotube strongly influences its local electronic, chemical, and mechanical properties. Few, if any, methods exist for resolving the strain energy and static frictional forces along the length of a deformed nanotube supported on a substrate. We present a method using nonlinear elastic rod theory in which we compute the flexural strain energy and static frictional forces along the length of single walled carbon nanotubes (SWCNTs) manipulated into various shapes …

Crack Identification By Multifractal Analysis Of A Dynamic Rotor Response, Grzegorz Litak, Jerzy T. Sawicki

Mechanical Engineering Faculty Publications

Multifractal analysis has been used to diagnose cracked and healthy rotors. Is has been shown that the complexity and regularity criteria of the dynamical systems defined by the multiple scaling of the time series can indicate the damages of the rotating shaft. Relation to the standard power spectrum technique has been also discussed.

Design And Development Of Rapid Battery Exchange Systems For Electric Vehicles To Be Used As Efficient Student Transportation, Jonathan A. Bevier

Master's Theses

Rapid battery exchange systems were built for an electric van and pedal assist electric bike as a method of eliminating the need to recharge the vehicles batteries in order to increase the feasibility of using electric propulsion as a method of efficient student transportation. After selecting proper materials it was found that the systems would need a protective coating to ensure consistent operation. 1020 cold rolled steel samples coated with multiple thicknesses of vinyl resin paint, epoxy resin paint, and powder coating were subjected to environmental wear tests in order to determine if the type and thickness of common protective …

Rail Short-Wavelength Irregularity Identification Based On Wheel-Rail Impact Response Measurements And Simulations, Y. Q. Sun, C. Cole, M. Mcclanachan, A. Wilson, S. Kaewunruen, M. B. Kerr

Faculty of Engineering - Papers (Archive)

Long and short-wavelength dip defects unavoidably exist on railway track top surface. Several manual measurement methods and AK track measurement car were used to measure and to identify these types of defects in a selected track section. The paper considers rail dip irregularities in detail when measured, the dip can be considered as two components. The first one is the large, long dip profile, which can be measured by the survey leveling. The other is a small short dip profile, which is superimposed on the large profile and can be measured using the dip gauge. The corresponding measurement and processed …

Mechanical Simulation Of Articular Cartilage Based On Experimental Results, Kevin Matthew Stewart

Master's Theses

Recently, a constituent based cartilage growth finite element model (CGFEM) was developed in order to predict articular cartilage (AC) biomechanical properties before and after growth. Previous research has noted limitations in the CGFEM such as model convergence with growth periods greater than 12 days. The main aims of this work were to address these limitations through (1) implementation of an exact material Jacobian matrix definition using the Jaumann-Kirchhoff (J-K) method and (2) quantification of elastic material parameters based upon research findings of the Cal Poly Cartilage Biomechanics Group (CPGBG). The J-K method was successfully implemented into the CGFEM and exceeded …

Carbon Fiber Leaf Springs For Adaptive Cross Country Skiing, William Drew Atkinson

Master's Theses

This work describes the development of a custom sit ski for US Ski Team paralympian Greg Mallory from concept through prototype fabrication. The ski consists of a custom seat molded specifically for the athlete, carbon fiber leaf springs, and a custom binding attachment system compatible with NNN style cross country bindings. The sit ski is designed to maximize poling power through the use of an upright rather than reclined seating position, allowing for increased utilization of core muscle strength. The springs were designed based on information gathered by a custom National Instruments data acquisition system, and stiffness analysis was conducted …

Tobacco Mosaic Virus Templated Synthesis Of One Dimensional Inorganic-Polymer Hybrid Fibres, Jianhua Rong, Fiona Oberbeck, Xinnan Wang, Xiaodong Li, Jerry Oxsher, Zhongwei Niu, Qian Wang

Faculty Publications

Inorganic–polymer hybrid nanofibres were prepared by using a rod-like tobacco mosaic virus (TMV) as a template. With tetraethylorthosilicate (TEOS) as a precursor, long silica-coated TMVfibres were formed via a head-to-tail assembly, which showed a substantial increase of the elastic modulus. Furthermore, homogenous titania–TMV hybrid fibres could be prepared using polyaniline-coated TMV fibres as a template, which were used to form a composite film that was able to sense liquefied petroleum gases.

Optimization And Stress Analysis Of A Single Stage Rotary Compressor Shaft, Arjunkumar Tummuri

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Arjunkumar Tummuri May 5, 2009.

College Of Engineering Senior Design Competition Spring 2009, University Of Nevada, Las Vegas

Fred and Harriet Cox Senior Design Competition Projects

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate the projects …

An On-Sun Parametric Study Of Solar Hydrogen Production Using Wo3 Photoanodes, Christopher K. Halford

UNLV Theses, Dissertations, Professional Papers, and Capstones

The solar production of hydrogen using photoactive electrodes is a topic receiving much attention in recent years. The use of thin metal oxide films as photoanodes allows the water splitting reaction to occur at a much lower applied voltage than would be necessary with a straight electrolysis process. Researchers have reported up to 18% solar to hydrogen efficiencies over short periods. The University of Nevada Las Vegas in conjunction with the UK based firm Hydrogen Solar have developed a prototype of this type of cell using a WO3 photoanode. An on-sun test facility has been constructed by the UNLV Center …

Experimental Evaluation And Modeling Of Engine Driven Heat Pump, Isaac Y. Mahderekal

UNLV Theses, Dissertations, Professional Papers, and Capstones

Recently, the Gas Engine-Driven Heat Pump (GHP) System has become an economic choice and more attractive climate control system than the conventional air conditioner due to its advantage in reducing fossil fuel consumption and environmental pollution. The GHP is a new type of heat pump in which the compressor (the core part) is driven by a gas engine. The GHP typically uses the work produced by the engine to drive a vapor-compression heat pump. At the same time, the waste heat rejected by the engine is used for heating purposes.

To improve the system performance of the GHP, a numerical …

Integrated Reliability And Sizing Optimization Of A Large Composite Structure, Christopher D. Eamon, Masoud Rais-Rohani

Civil and Environmental Engineering Faculty Research Publications

In this paper, we present the application of probabilistic design modeling and reliability-based design optimization (RBDO) methodology to the sizing optimization of a composite advanced submarine sail structure under parametric uncertainty. With the help of probabilistic sensitivity analysis, the influence of individual random variables on each structural failure mode is examined, and the critical modes are treated as probabilistic design constraints under consistent lower bounds on the corresponding reliability indices. Whereas the failure modes are applied to structural components in the solution of the RBDO problem, the overall system reliability is also evaluated as a post-optimization step. The results indicate …

Multiscale Modeling Of Impact On Heterogeneous Viscoelastic Solids With Evolving Microcracks, Flavio V. Souza

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Multiscale computational techniques play a major role in solving problems related to viscoelastic composite materials due to the complexities inherent to these materials. In the present work, a numerical procedure for multiscale modeling of impact on heterogeneous viscoelastic solids containing evolving microcracks is proposed in which the (global scale) homogenized viscoelastic incremental constitutive equations have the same form as the local scale viscoelastic incremental constitutive equations, but the homogenized tangent constitutive tensor and the homogenized incremental history dependent stress tensor depend on the amount of damage accumulated at the local scale. Furthermore, the developed technique allows the computation of the …

Us Patent 7,501,922: Permanent Magnetic Male And Female Levitation Supports, Sanza Kazadi

Sanza Kazadi

Interfacial Energy Between Carbon Nanotubes And Polymers Measured From Nanoscale Peel Tests In The Atomic Force Microscope, Mark C. Strus, Camilo I. Cano, R. Byron Pipes, Cattien V. Nguyen, Arvind Raman

Other Nanotechnology Publications

The future development of polymer composite materials with nanotubes or nanoscale fibers requires the ability to understand and improve the interfacial bonding at the nanotube-polymer matrix interface. In recent work [Strus MC, Zalamea L, Raman A, Pipes RB, Nguyen CV, Stach EA. Peeling force spectroscopy: exposing the adhesive nanomechanics of one-dimensional nanostructures. Nano Lett 2008;8(2):544–50], it has been shown that a new mode in the Atomic Force Microscope (AFM), peeling force spectroscopy, can be used to understand the adhesive mechanics of carbon nanotubes peeled from a surface. In the present work, we demonstrate how AFM peeling force spectroscopy can be …

Low Temperature, Organic-Free Synthesis Of Ba3B6O9(Oh)6 Nanorods And Ss-Bab2O4 Nanospindles, Rui Li, Xinyoung Tao, Xiaodong Li

Faculty Publications

Using a low temperature, organic-free hydrothermal technique, single-crystalline barium polyborate Ba₃B₆O₉(OH)₆ (BBOH) nanorods were synthesized. It was found that β-BaB₂O₄(BBO) nanospindles can be achieved by annealing the BBOH nanorods at a relatively low temperature of 810 °C. Transmission electron microscopy (TEM), X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) techniques were used to characterize these nanomaterials. The formation mechanisms are discussed in conjunction with the crystallographic characteristics and surface energy of the BBOH nanorods and BBO nanospindles. UV-vis absorption spectra demonstrated that both BBOH nanorods and BBO nanospindles are …

A System For Measuring The Lift And Drag Forces Of A Spinning Golf Ball Held Fixed Within A Wind Tunnel, Ryan R. Miller

Master's Theses

A system was designed, built and tested in order to test the aerodynamic properties of a standard golf ball in a wind tunnel manufactured by ELD, Inc. model 406(B). The system consists of a rotating shaft, on which the golf ball is attached, connected to a two-axis force transducer. Additionally, an automated data acquisition system was built for enhanced precision of measurements. Data for wind speeds up to 160 ft/s and rotational speeds up to 8,600 rpm were obtained and analyzed. The purpose of the designed apparatus was to allow for studies to better understand the lift and drag coefficients …

Newsletters Of First 10 Years, Tractor Museum

Friends of the Larsen Tractor Museum

Newsletters distributed to supporters of the Larsen Tractor Museum.

1998 Spring Newsletter 1 - Non-profit Status, Dedication of Museum, Nebraska Tractor Test Law Beginnings

1998 Winter Newsletter 2 - First Annual Meeting, Library Established, State Fair Report, Winnepeg Plowing Contests

1999 Spring Newsletter 3 - Nebraska State Museum Affiliation, Fundraising Goals, Fuel Saving Devices in the 1920s

1999 Fall Newsletter 4 - Museum Studies Luis Vasquez, Tractor Raffle, Renovation Goals, Fundraising Goals, Annalyzing Tractor Test Results

1999 Winter Newsletter 5 - Mission Statement, Logo and Letterhead, Tractor Storage Facility, Bylaw Amendments, Hand Tool History, The Davidson Traction Dynamometer

2000 Spring …

Convergence, Adaptive Refinement, And Scaling In 1d Peridynamics, Florin Bobaru Ph.D., Mijia Yabg Ph.D., Leonardo F. Alves M.S., Stewart A. Silling Ph.D., Ebrahim Askari Ph.D., Jifeng Xu Ph.D.

Department of Engineering Mechanics: Faculty Publications

We introduce here adaptive refinement algorithms for the non-local method peridynamics, which was proposed (in J. Mech. Phys. Solids 2000; 48:175–209) as a reformulation of classical elasticity for discontinuities and long-range forces. We use scaling of the micromodulus and horizon and discuss the particular features of adaptivity in peridynamics for which multiscale modeling and grid refinement are closely connected. We discuss three types of numerical convergence for peridynamics and obtain uniform convergence to the classical solutions of static and dynamic elasticity problems in 1D in the limit of the horizon going to zero. Continuous micromoduli lead to optimal rates of …

Thermocapillary Effects In Driven Dewetting And Self-Assembly Of Pulsed Laser-Irradiated Metallic Films, Agegnehu Atena, Mikhail Khenner

Mathematics Faculty Publications

In this paper the lubrication-type dynamical model is developed of a molten, pulsed laser-irradiated metallic film. The heat transfer problem that incorporates the absorbed heat from a single beam or interfering beams is solved analytically. Using this temperature field, we derive the 3D long-wave evolution PDE for the film height. To get insights into dynamics of dewetting, we study the 2D version of the evolution equation by means of a linear stability analysis and by numerical simulations. The stabilizing and destabilizing effects of various system parameters, such as the peak laser beam intensity, the film optical thickness, the Biot and …