Engineering Science and Materials Commons^™

Elements Of Study On Dynamic Materials, Marine Rousseau, Gerard A. Maugin, Mihhail Berezovski

Publications

As a preliminary study to more complex situations of interest in small-scale technology, this paper envisages the elementary propagation properties of elastic waves in one-spatial dimension when some of the properties (mass density, elasticity) may vary suddenly in space or in time, the second case being of course more original. Combination of the two may be of even greater interest. Toward this goal, a critical examination of what happens to solutions at the crossing of pure space-like and time-like material discontinuities is given together with simple solutions for smooth transitions and numerical simulations in the discontinuous case. The effects on …

An Experimental Investigation Of Friction Bit Joining In Az31 Magnesium And Advanced High-Strength Automotive Sheet Steel, Rebecca Gardner

Theses and Dissertations

Friction Bit Joining (FBJ) is a recently developed spot joining technology capable of joining dissimilar metals. A consumable bit cuts through the upper layer of metal to be joined, then friction welds to the lower layer. The bit then snaps off, leaving a flange. This research focuses on FBJ using DP980 or DP590 steel as the lower layer, AZ31 magnesium alloy as the top layer, and 4140 or 4130 steel as the bit material. In order to determine optimal settings for the magnesium/steel joints, experimentation was performed using a purpose-built computer controlled welding machine, varying factors such as rotational speeds, …

Natural Fibers And Fiberglass: A Technical And Economic Comparison, Justin Andrew Zsiros

Theses and Dissertations

Natural fibers have received attention in recent years because of their minimal environmental impact, reasonably good properties, and low cost. There is a wide variety of natural fibers suitable for composite applications, the most common of which is flax. Flax has advantages in tensile strength, light weight, and low cost over other natural fibers. As with other natural and synthetic fibers, flax is used to reinforce both thermoset and thermoplastic matrices. When flax is used in thermoplastic matrices, polypropylene and polyethylene are the main resins used. Although at first glance flax may seem to be a cheaper alternative to fiberglass, …

Naturally Occurring Nanoparticles From English Ivy: An Alternative To Metal-Based Nanoparticles For Uv Protection, Lijin Xia, Scott C. Lenaghan, Mingjun Zhang, Zhili Zhang, Quanshui Li

Faculty Publications and Other Works -- Mechanical & Aerospace Engineering/Engineering Science (MAES) (UTSI)

Background

Over the last decade safety concerns have arisen about the use of metal-based nanoparticles in the cosmetics field. Metal-based nanoparticles have been linked to both environmental and animal toxicity in a variety of studies. Perhaps the greatest concern involves the large amounts of TiO₂ nanoparticles that are used in commercial sunscreens. As an alternative to using these potentially hazardous metal-based nanoparticles, we have isolated organic nanoparticles from English ivy (Hedera helix). In this study, ivy nanoparticles were evaluated for their potential use in sunscreens based on four criteria: 1) ability to absorb and scatter ultraviolet light, …

Design, Fabrication, Structural Testing, And Numerical Analysis Of A Small Scale Composite Wing, Jacob David Gaunt, Juan Carlos Flores, Vincent Andrew Perry

Aerospace Engineering

A small scale composite wing based on a design found on an experimental aircraft was designed, constructed, and tested dynamically and statically. The wing was constructed similarly to an experimental aircraft wing. The performed static test was intended to produce pure bending. Strain gages were used to measure strains on the wing structure. The strains were converted to stresses to aid in analysis. The static test results suggested that the wing was actually under torsion. Four structural modes were found from the static test. A finite element analysis model was made to compare experimental results to numerical analytical results. The …

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

Department of Mechanical Engineering-Engineering Mechanics eNewsBrief

No abstract provided.

Fast Energy Loss Computation And Fuzzy-Based Shunt Capacitor Insertion, Philadelphia University

Philadelphia University, Jordan

No abstract provided.

Mechanical Milling Of Co-Rich Melt-Spun Sm-Co Alloys, Farhad Reza Golkar-Fard

Engineering Mechanics Dissertations & Theses

MECHANICAL MILLING OF CO-RICH MELT-SPUN SM-CO ALLOYS Farhad Reza Golkar-Fard, M.S UNIVERSITY OF NEBRASKA, 2010 Advisor: Jeffrey E. Shield Rare-earth, high-energy permanent magnets are currently the best performing permanent magnets used today. The discovery of single domain magnetism in 1950’s ultimately led to the development of nanocomposite magnets which had superior magnetic properties. Previous work has shown that mechanical milling (MM) effectively generates nanoscale structures in Sm-Co-based alloys. MM of more Co-rich, melt-spun Sm-Co alloys (up to the eutectic composition) and the role of initial structure on the milling behavior were investigated.

Sm-Co alloys with compositions of Sm_10.5Co …

Coupled Dem-Fem For Dynamic Analysis Of Granular Systems In Bending, Kitti Rattanadit

Engineering Mechanics Dissertations & Theses

Characterizing the dynamic behavior of granular materials is one of the great challenges in the mechanics of granular matter. Methods for evaluating the mechanical properties of granular matter have applications in a variety of industries, mining and geotechnical activities, defense and military operations. A coupled 2D Discrete Element Method-Finite Element Method (DEM-FEM) code, called "BobKit", is developed and implemented for analyzing the behavior of a 2D granular layer on top of an elastic beam under deforming (quasi-static) or vibrating (dynamic) of the beam. The explicit time-integration dynamic code is used to simulate quasi-static and dynamic bending of the granular layer …

System Modeling And Power Management Strategy For A Series Hydraulic Hybrid Vehicle, Sisay Molla

All Theses

A hydraulic hybrid vehicle draws propulsion power from an internal combustion engine as its prime mover and a gas-charged hydro-pneumatic accumulator as its energy buffer. The accumulator serves the purposes of storing regenerated braking energy and supplementing engine power as determined by an on-board power management strategy. In the configuration known as a series hydraulic hybrid powertrain, the engine is mechanically decoupled from the vehicle's wheels thereby offering excellent opportunities for maximizing energy efficiency and reducing pollutant emissions.
This thesis dealt with the development of a causally interconnected, non-linear, dynamic model of a series hydraulic hybrid powertrain featuring independently controllable …

Re-Engineering A Trash/Recycling Collection Vehicle Based On Challenging Customer Requirements, Edward Smith

All Theses

Engineering design starts with the definition of design requirements. These requirements define the design problem and must be satisfied for a solution to be acceptable. While many design methodologies exist for defining design requirements, none presently provides a systematic approach for designers to challenge requirements. Yet, Pahl and Beitz, Hazelrigg, and Suh all argue that a designer should continually question the need for each requirement and refine them as the product evolves. Thus, there exists a need to develop a comprehensive method that enables a designer to verify, review/question, and revise requirements throughout the design process. This research uses the …

Electrokinetic Manipulation Of Particles And Cells In Microfluidic Devices, Christopher Church

All Theses

With the recent advancement in micro-fabrication technology, lab-on-a-chip devices have been developed in order to perform biological analysis through cell manipulation. Microchannels used in these lab-on-a-chip devices have been demonstrated to accurately perform many different cell manipulation techniques such as focusing, separation, trapping, and lysis. Although there are many methods available for these techniques, electrokinetics has been rapidly gaining popularity due to the simplicity of application and removal of the need for in channel micro-structures. This thesis studies the use of electrokinetic flow and accompanying phenomena in various structured microchannels to perform focusing, separation, trapping, and lysis of cells. Three …

Comprehensive Analysis Of A Student-Centered Active-Learning Integrated Statics And Dynamics Course For Mechanical Engineers, Marisa Orr

All Theses

The Student-Centered Active Learning in Undergraduate Programs (SCALE-UP) approach to instructional design was adapted with the goal of delivering more effective statics, dynamics and multivariate calculus instruction and integrated course curricula. Inquiry-based learning exercises were designed, incorporating material from statics and dynamics into multivariable calculus, and vice-versa, as well as integrating statics and dynamics into one course. Analysis included an exploration of student study habits, multiple measures of course effectiveness, and an examination of curricular effects. Challenges of implementation are also discussed.
Study habits of students in an integrated Statics and Dynamics course were assessed through a voluntary survey in …

A Proposed Method To Identify Requirements Significant To Mass Reduction, James Mclellan

All Theses

Reducing the mass of engineering products holds the potential for significant benefits by reducing material costs, environmental impact, transportation costs, and in the case of vehicles, reducing fuel consumption. While there are many approaches for reducing mass, analyzing requirements has the greatest potential since requirements definition is the earliest phase of product development, where the most design freedom exists. This thesis proposes a requirement analysis method that identifies requirements that impact significant amounts of mass. The research hypothesis is: Engineering requirements can be represented and processed in a systematic manner and linked to physical components and systems, thus enabling mass …

Modeling Of A Porous Metal Foam Cryogenic Counter Flow Heat Exchanger, Craig Fortier

All Theses

This thesis involves the modeling of cryogenic fluids through a porous metal foam counter flow heat exchanger. Although much research has been completed involving light weight high porosity metal foams in recent years, research performed on the subject of mid range porosities in metal foams and their use in heat exchangers has been relatively untouched. Even less literature is available pertaining to the effects of cryogenic fluids in porous metal foams.
Much about heat exchanger performance and pressure drop depends on the structure and relative density of the metal foams. This has been elaborated in several sources, but only for …

Vehicle Steering Systems - Hardware-In-The-Loop Simulator, Driving Preferences, And Vehicle Intervention, Jesse Black

All Dissertations

The steering system is a critical component of all ground vehicles regardless of their propulsion source. Chassis directional control is provided by the steering system, which in turn relays valuable feedback about the road and vehicle behavior. As the primary feedback channel to the driver, the steering system also delivers the initial perception of a vehicle's handling and responsiveness to the consumer. Consequently, the steering system is an important aspect of the vehicle's evaluation and purchasing process, even if drivers are unaware of its direct influence in their decision making. With automobile purchases potentially hinging on the steering system, a …

Interpretability Analysis Of Function Structures At Various Levels Of Abstraction: A User Study, Jonathan Thomas

All Theses

Function models are used during the conceptual design phase of the design process to model the intended use or objective of a product, independent of the products physical form. Function models also aid in guiding design activities such as generating concepts and allocating design team resources. Recent research efforts have focused on the formalization of functional models through a controlled vocabulary and archival of functional representations in computer-based repositories. However, the usefulness and interpretability of these function models has not been rigorously evaluated.
This thesis presents the results of two controlled user studies to ascertain the interpretability of functional representations …

Modeling And Control Of A Wind Farm And Electrolyzer System Connected To An Electrical Gird, Dr. Adel A. Elbaset, Prof. Dr. Omar H. Abdalla

Dr. Adel A. Elbaset

This paper presents modeling and control analysis of a combined Wind-H2 system connected to an electrical grid and supplying a local electric load. The system consists of a wind farm for electricity generation and an electrolyzer to produce hydrogen for a filling station. A computer program has been developed in MATLAB for simulating the operation and control of the integrated system. Energy balances and hydrogen flow balances are calculated for each time step based on a system model and the specified control strategy. The input of this program are hourly wind speed, characteristics of wind turbine generators, hourly load demand, …

"Elementary" Engineering Experiences, Steven E. Butt, Tycho K. Fredericks

Academic Leadership Academy

Through early exposure to engineering, this program attempts to open the minds of children to future exciting opportunities that are accessible to them if they are appropriately prepared in mathematics and science. The program consists of a two to four hour session in which students, parents, and teachers are walked through a sequence of hands-on activities in various locations within the CEAS building. In addition to immersing the students in engaging activities, time is also invested in helping students understand who engineers are and what engineers do. This includes describing the various engineering disciplines, and their workplaces.

Processing A Nickel Nanostrand And Nickel Coated Carbon Fiber Filled Conductive Polyethylene By Injection Molding, David Anthony Whitworth

Theses and Dissertations

A new method for pre-impregnating nickel coated carbon fiber with a thermoplastic polymer to make towpreg, similar to a recently developed coating-line by João P. Nunes et al and a new electrically conductive thermoplastic are developed. A melted bath was used to help mitigate health concerns and waste for dispersion of nickel coated carbon fibers (NCF) in low density polyethylene (LDPE). This towpreg was then mixed with more LDPE or a mixture of LDPE and nickel nanostrands (NiNS) to a desired filler volume fraction to test the electrical conductivity of the composite. Some of these mixtures were then injection molded …