Mechanical Engineering Commons^™

Building A Successful Transatlantic Collaboration In Engineering/Technological Education; Lessons From A Six Year Journey, Donal Mchale, Mark Mcgrath, John Lawlor

Conference Papers

This paper reflects on key learning’s from the first six-years (2004-2010) of the development of a collaborative journey of two trans-Atlantic higher-educational institutions. It describes the progress towards building a sustainable and innovative international educational partnership in Engineering/Technological education between the Technological University Dublin,DublinIrelandandPurdue University,Indiana,USA.

In particular, the paper provides insight into the iterative stages of development of this relationship. It reflects on some of the key challenges and it recognises the critical enablers of success. It focuses on challenges and solutions in the following six important areas

(i) The partnership initiation stage. Key considerations and important enablers of future …

A Prediction Of The Acoustical Output Of A Golf Driver Head Using Finite Elements, Roger Sharpe

Master's Theses

A simulation was created using LS-DYNA® to determine the acoustical properties of a golf ball and golf driver head impact. LS-DYNA® has a coupled finite element analysis (FEA) and boundary element method (BEM) solver that uses the integral form of Helmholtz’s acoustic wave equation to deliver predicted sound pressure levels at predetermined acoustic points. Validation of the modeling was done on a simple plate donated by Titleist Golf. The plate was modeled and meshed using TrueGrid and impacted by a three layer golf ball model derived from “Tanka’s” paper on multilayered golf balls. The final converging model consisted of 10,900 …

Functionally Graded Materials By Laser Metal Deposition (Preprint), Syamala R. Pulugurtha, Joseph William Newkirk, Frank W. Liou, Hsin-Nan Chou

Materials Science and Engineering Faculty Research & Creative Works

Fabrication of functionally graded materials (FGMs) by laser metal deposition (LMD) has the potential to offer solutions to key engineering problems over the traditional metalworking techniques. But the issues that need to be addressed while building FGMs are intermixing in the layers and cracking due to the residual stresses. This paper is to present the study of the effect of process parameters (laser power and travel speed) on the degree of dilution between the substrate (or, previous layer) and powder material for few metallurgical systems.

Three-Dimensional Modeling Of Transport Phenomena And Their Effect On The Formation Of Ripples In Gas Metal Arc Welding, Z. H. Rao, J. Zhou, S. M. Liao, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

Distinct, periodic arc-shaped ripples are observed on the surface of the weld bead in almost any welded components which have a significant effect on weld quality. This article presents the complex transport phenomena and their effect on the formation of ripples in three-dimensional moving gas metal arc welding. The transient distributions of the melt flow velocity and temperature in the weld pool, weld pool shape and dynamics, and solidified weld bead are calculated. It is found that the surface ripples are formed by the interplay between the up-and-down weld pool dynamics, caused mainly by the periodic droplet impingements, and the …

Combined H∞-Feedback Control And Iterative Learning Control Design With Application To Nanopositioning Systems, Brian E. Helfrich, Chibum Lee, Douglas A. Bristow, Jingyan Dong, Srinivasa M. Salapaka, Placid M. Ferreira, X. H. Xiao, Andrew G. Alleyne

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This paper examines a coordinated feedback and feedforward control design strategy for precision motion control (PMC) systems. It is assumed that the primary exogenous signals are repeated; including disturbances and references. Therefore, an iterative learning control (ILC) feedforward strategy can be used. The introduction of additional non-repeating exogenous signals, including disturbances, noise, and reset errors, necessitates the proper coordination between feedback and feedforward controllers to achieve high performance. A novel ratio of repeated versus non-repeated signal power in the frequency domain is introduced and defined as the repetitive-to-non-repetitive (RNR) ratio. This frequency specific ratio allows for a new approach to …

Modeling Disk Cracks In Rotors By Utilizing Speed Dependent Eccentricity, Andrew L. Gyekenyesi, Jerzy T. Sawicki, Wayne C. Haase

Mechanical Engineering Faculty Publications

This paper discusses the feasibility of vibration-based structural health monitoring for detecting disk cracks in rotor systems. The approach of interest assumes that a crack located on a rotating disk causes a minute change in the system’s center of mass due to the centrifugal force induced opening of the crack. The center of mass shift is expected to reveal itself in the vibration vector (i.e., whirl response; plotted as amplitude and phase versus speed) gathered during a spin-up and/or spin-down test. Here, analysis is accomplished by modeling a Jeffcott rotor that is characterized by analytical, numerical, and experimental data. The …

Solar Power And The Electric Grid, Energy Analysis, Nrel Energy Analysis

Publications (E)

In today’s electricity generation system, different resources make different contributions to the electricity grid. This fact sheet illustrates the roles of distributed and centralized renewable energy technologies, particularly solar power, and how they will contribute to the future electricity system. The advantages of a diversified mix of power generation systems are highlighted.

Me-Em Enewsbrief, March 2010, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering eNewsBrief

No abstract provided.

Multidisciplinary Considerations In The Design Of Wings And Wing Tip Devices, Andrew Ning, Ilan Kroo

Faculty Publications

Conceptual wing design analysis methods are combined with numerical optimization to find minimum drag wings subject to constraints on lift, weight, pitching moment, and stall speed. Tip extensions and winglets designed for minimum drag achieve similar performance, with the optimal solution depending on the ratio of the maneuver lift coecient to the cruise lift coecient. The results highlight the importance of accounting for the depth of the wing structural box in the weight model, and including constraints on stall speed. For tailless aircraft, C-wings show a slight performance advantage over wings with winglets when longitudinal trim and stability constraints are …

Note: Thermal Analog To Atomic Force Microscopy Force-Displacement Measurements For Nanoscale Interfacial Contact Resistance, Brian D. Iverson, John E. Blendell, Suresh V. Garimella

Faculty Publications

Thermal diffusion measurements on polymethylmethacrylate-coated Si substrates using heated atomic force microscopy tips were performed to determine the contact resistance between an organic thin film and Si. The measurement methodology presented demonstrates how the thermal contrast signal obtained during a force-displacement ramp is used to quantify the resistance to heat transfer through an internal interface. The results also delineate the interrogation thickness beyond which thermal diffusion in the organic thin film is not affected appreciably by the underlying substrate.

Bidirectional Electrowetting Actuation With Voltage Polarity Dependence, Nathan B. Crane, Alex A. Volinsky, Pradeep Mishra, Ajay Rajgadkar, Mehdi Khodayari

Faculty Publications

This work presents an electrowetting system in which the actuation direction depends on the polarity of the applied voltage. Since electrowetting response depends on the voltage squared, it is typically independent of voltage sign to first order. However, the introduction of an electrochemicaal diode into the equivalent electrical circuit permits polarity-dependent behavior. Electrochemical diodes were created by making holes in the dielectric. The aluminum electrodes passivate and prevent current flow in one direction, creating diode-like behavior with high breakdown voltage. The resulting actuation forces were directly measured and are of comparable magnitude for both actuation directions.

Nuts And Bolts - Ltm Newsletters, Tractor Museum

Friends of the Larsen Tractor Museum

Newsletters published by the Larsen Tractor Museum in 2010

Where do we grow from here? by Curt McConnell, editor

Chris Ford has big plans for small groups in 2010 by Curt McConnell, editor

News from Exhibits by Luis Vasquez, chair of collections committee

Engine comes together as Co-Op E3 progresses by Curt McConnell

Description of our Sound Level Measuring and Analyzing Equipment by Lou Leviticus

Development of conservation tillage methods by Bill Splinter, museum director

Curator's Report by Lou Leviticus

Associate Report by Jeremy Steele, museum associate

Obituary Note - Robert Kleis

Building America Industrialized Housing Partnership (Baihp Ii), Annual Report - Budget Period 4 (Bp4), January 01, 2009 - December 31, 2009, Florida Solar Energy Center, Robert Abernethy

FSEC Energy Research Center®

This annual report summarizes the work conducted by the Building America Industrialized Housing Partnership (BAIHP - www.baihp.org) during the fourth budget period (BP4) of our contract, January 1, 2009 to December 31, 2009. Progress from the three previous budget periods is included for context.

BAIHP is led by the Florida Solar Energy Center (FSEC) of the University of Central Florida. With over 50 Industry Partners including factory and site builders, work was performed in four task areas:

• Task 1: System Evaluations
• Task 2: Prototype House Evaluations
• Task 3: Community Scale Evaluations
• Task 4: Post- Phase 3 Activities.

In Task 1, …

Design And Validation Of A General Purpose Robotic Testing System For Musculoskeletal Applications, Lawrence D. Noble, Robb W. Colbrunn, Dong-Gil Lee, Antonie J. Van Den Bogert, Brian L. Davis

Mechanical Engineering Faculty Publications

Orthopaedic research on in vitro forces applied to bones, tendons, and ligaments during joint loading has been difficult to perform because of limitations with existing robotic simulators in applying full-physiological loading to the joint under investigation in real time. The objectives of the current work are as follows: (1) describe the design of a musculoskeletal simulator developed to support in vitro testing of cadaveric joint systems, (2) provide component and system-level validation results, and (3) demonstrate the simulator’s usefulness for specific applications of the foot-ankle complex and knee. The musculoskeletal simulator allows researchers to simulate a variety of loading conditions …

Tidal Energy Update 2009, Fergal O'Rourke, Fergal Boyle, Anthony Reynolds

Articles

Tidal energy has the potential to play a valuable part in a sustainable energy future. It is an extremely predictable energy source, depending only on the gravitational pull of the moon and the sun and the centrifugal forces created by the rotation of the earth-moon system. Tidal energy has been exploited on a significant scale since the construction of the La Rance tidal barrage in France in 1967. A tidal barrage utilises the potential energy of the tide and has proven to be very successful, despite opposition from environmental groups. Kinetic energy can also be harnessed from tidal currents to …

Adhesion At Diamond /Metal Interfaces: A Density Functional Theory Study, Haibo Guo, Yue Qi, Xiaodong Li

Faculty Publications

To understand the basic material properties required in selecting a metallic interlayer for enhanced adhesion of diamondcoatings on the substrates, the interfaces between diamond and metals with different carbide formation enthalpies (Cu, Ti, and Al) are studied using density functional theory. It is found that the work of separation decreases, while the interface energy increases, with the carbide formation enthalpy ΔHf (Tiy_s (Ti>Cu>Al), is needed to achieve a higher overall interface strength. In addition, when the surface energy is larger than the interface energy, a wetted diamond/metal interface is formed during diamondnucleation, providing the strongest adhesion …

Integrated Vehicle Thermal Management For Advanced Vehicle Propulsion Technologies: Preprint., K. Bennion, M. Thornton

Publications (T)

A critical element to the success of new propulsion technologies that enable reductions in fuel use is the integration of component thermal management technologies within a viable vehicle package. Vehicle operation requires vehicle thermal management systems capable of balancing the needs of multiple vehicle systems that may require heat for operation, require cooling to reject heat, or require operation within specified temperature ranges. As vehicle propulsion transitions away from a single form of vehicle propulsion based solely on conventional internal combustion engines (ICEs) toward a wider array of choices including more electrically dominant systems such as plug-in hybrid electric vehicles …

Technology Improvement Pathways To Cost-Effective Vehicle Electrification: Preprint, A. Brooker, M. Thornton, J. Rugh

Publications (T)

Electrifying transportation can reduce or eliminate dependence on foreign fuels, emission of green house gases, and emission of pollutants. One challenge is finding a pathway for vehicles that gains wide market acceptance to achieve a meaningful benefit. This paper evaluates several approaches aimed at making plug-in electric vehicles (EV) and plug-in hybrid electric vehicles (PHEVs) cost-effective including opportunity charging, replacing the battery over the vehicle life, improving battery life, reducing battery cost, and providing electric power directly to the vehicle during a portion of its travel. Many combinations of PHEV electric range and battery power are included. For each case, …

Steady-Periodic Heating In Parallel-Plate Microchannel Flow With Participating Walls, Kevin D. Cole

Department of Mechanical and Materials Engineering: Faculty Publications

Simulations are presented for thermal sensing of steady laminar flow in a parallel-plate microchannel. Steady-periodic heating is introduced at the channel wall and temperatures are reported at upstream and downstream locations to represent temperature sensors. Exact analytical expressions for the temperature are given in the form of integrals, and numerical values are found by quadrature. Because axial conduction is prominent, there is a well-defined measurable flow range associated with each thermal-sensor geometry. Various fluid-flow rates, heating frequencies, sensor locations, and wall properties are explored. The results are given as a design correlation which shows the extent to which a given …

Effects Of Shielding Gas Compositions On Arc Plasma And Metal Transfer In Gas Metal Arc Welding, Z. H. Rao, S. M. Liao, Hai-Lung Tsai

Mechanical and Aerospace Engineering Faculty Research & Creative Works

This article presents the effects of shielding gas compositions on the transient transport phenomena, including the distributions of temperature, flow velocity, current density, and electromagnetic force in the arc and the metal, and arc pressure in gas metal arc welding of mild steel at a constant current input. The shielding gas considered includes pure argon, 75% Ar, 50% Ar, and 25% Ar with the balance of helium. It is found that the shielding gas composition has significant influences on the arc characteristics; droplet formation, detachment, transfer, and impingement onto the workpiece; and weld pool dynamics and weld bead profile. As …