Mechanical Engineering Commons^™

Mechanical Behavior Of A Magnesium Alloy Nanocomposite Under Conditions Of Static Tension And Dynamic Fatigue, T. S. Srivatsan, C. Godbole, T. Quick, M. Paramsothy, M. Gupta

Mechanical Engineering Faculty Research

In this paper, the intrinsic influence of nano-alumina particulate (Al₂O_3p) reinforcements on microstructure, microhardness, tensile properties, tensile fracture, cyclic stress-controlled fatigue, and final fracture behavior of a magnesium alloy is presented and discussed. The unreinforced magnesium alloy (AZ31) and the reinforced composite counterpart (AZ31/1.5 vol.% Al₂O₃) were manufactured by solidification processing followed by hot extrusion. The elastic modulus, yield strength, and tensile strength of the nanoparticle-reinforced magnesium alloy were noticeably higher than the unreinforced counterpart. The ductility, quantified by elongation-to-failure, of the composite was observably lower than the unreinforced monolithic counterpart (AZ31). …

Objectives And Constraints For Wind Turbine Optimization, Andrew Ning, Rick Damiani, Patrick Moriarty

Faculty Publications

Efficient extraction of wind energy is a complex multidisciplinary process. This paper examines common objectives used in wind turbine optimization problems. The focus is not on the specific optimized designs, but rather on understanding when certain objectives and constraints are necessary, and what their limitations are. Maximizing annual energy production, or even using sequential aero/structural optimization, is shown to be significantly suboptimal compared to integrated aero/structural metrics. Minimizing the ratio of turbine mass to annual energy production can be effective for fixed rotor diameter designs, as long as the tower mass is estimated carefully. For variable diameter designs, the predicted …

State Of The Irish Housing Stock - Modelling The Heat Losses Of Ireland’S Existing Detached Rural Housing Stock & Estimating The Benefit Of Thermal Retrofit Measures On This Stock, Ciara Ahern, Philip Griffiths, Micheal O'Flaherty

Articles

Ireland’s housing stock has been identified as being amongst the least energy efficient in Northern Europe. Consequently, atmospheric emissions are greater than necessary. Government funded schemes have been introduced to incentivise the uptake of thermal retrofit measures in the domestic Irish market. A study of Ireland’s housing highlights the dominance of detached houses (43%), 72% of which are rurally located and are predominantly heated with fuel oil. This paper investigates the economic and carbon case for thermal retrofit measures to the existing detached, oil centrally heated, rural housing stock. The study found the case for energy efficiency measures to be …

Room-Temperature Organic Ferromagnetism In The Crystalline Poly(3-Hexylthiophene): Phenyl-C61-Butyric Acid Methyl Ester Blend Film, Bin Yang, Zhengguo Xiao, Yongbo Yuan, Tanjore V. Jayaraman, Jeffrey E. Shield, Ralph Skomski, Jinsong Huang

Department of Mechanical and Materials Engineering: Faculty Publications

Pronounced ferromagnetism was observed in a crystalline blend film of conjugated polymer poly(3-hexylthiophene) (P3HT) and phenyl-C61-butyric acid methyl ester (PCBM) by using magnetic force microscopy measurements. A substantial room-temperature saturation magnetization of about 0.65 emu g−1 was measured by an alternating gradient field magnetometer. Multiple experimental evidences demonstrate the charge transfer from the P3HT to the PCBM and the formation of P3HT crystal domain are expected to be two critical factors for the originals of room-temperature organic ferromagnetism.

Resistance Factors For Ductile Frp-Reinforced Concrete Flexural Members, Bashar Behnam, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

To prevent damage caused by corroding reinforcement, fiber reinforced polymer (FRP) reinforcing bars have been used in place of steel in a relatively small but increasing number of structures in the civil infrastructure. A concern with the use of traditional FRP bars, however, is the resulting lack of ductility. This problem has been overcome with the development of a new generation of composite reinforcement, ductile hybrid FRP (DHFRP) bars. However, standards that address the design of DHFRP bars are unavailable, and appropriate resistance factors for the use of DHFRP reinforcement are unknown. In this study, a reliability analysis is conducted …

Reliability Analysis Of Rc Beams Exposed To Fire, Christopher D. Eamon, Elin A. Jensen

Civil and Environmental Engineering Faculty Research Publications

A procedure for conducting reliability analysis of reinforced concrete beams subjected to a fire load is presented. This involves identifying relevant load combinations, specifying critical load and resistance random variables, and establishing a high-temperature performance model for beam capacity. Based on the procedure, an initial reliability analysis is conducted using currently available data. Significant load random variables are taken to be dead load, sustained live load, and fire temperature. Resistance is in terms of moment capacity, with random variables taken as steel yield strength, concrete compressive strength, placement of reinforcement, beam width, and thermal diffusivity. A semi-empirical model is used …

Experimental Study Of Nanofiber Production Through Forcespinning, Simon Padron, Arturo Fuentes, Dumitru Caruntu, Karen Lozano

Mechanical Engineering Faculty Publications

A newly developed method of producing nanofibers, called forcespinning, has proven to be a viable alternative to mass produce nanofibers. Unlike electrospinning, the most common method currently being employed (which draws fibers through the use of electrostatic force), forcespinning utilizes centrifugal forces which allow for a host of new materials to be processed into nanofibers (given that electric fields are not required) while also providing a significant increase in yield and ease of production. This work presents a detailed explanation of the fiber formation process. The study is conducted using high speed photography to capture the jet initiation process at …

Hydrophobic Hydrogel Caged H3Po4 As A New Class Of High-Temperature Proton Exchange Membranes With Enhanced Acid Retention, Qunwei Tang, Guoging Qian, Kevin Huang

Faculty Publications

We herein report a new class of high-temperature proton exchange membranes comprised of poly(acrylic acid-graft-hexadecyltrimethylammonium bromide) (PAA-g-CTAB) or poly(acrylic acid)-graft-poly(ethylene glycol) (PAA-g-PEG) hydrophobic hydrogel caged H₃PO₄. The membranes exhibit reasonable proton conductivity, enhanced H₃PO₄ retention ability and low solubility in water, making them promising as potential high performance and robust electrolytes for high-temperature proton exchange membrane fuel cells. Although the proton conductivity is still lower than that of H₃PO₄ doped PBI membranes, the new concept provides a different approach to proton exchange membranes for acid retention.

Capillary Phenomena: Investigations In Compressed Bubble Migration, Geometric Wetting, And Blade-Bound Droplet Stability, William Henry Blackmore

Dissertations and Theses

Capillary flows continue to be important in numerous spacecraft systems where the effective magnitude of the gravity vector is approximately one millionth that of normal Earth gravity. Due to the free fall state of orbiting spacecraft, the effects of capillarity on the fluid systems onboard can dominate the fluid behavior over large length scales. In this research three investigations are pursued where the unique interplay between surface tension forces, wetting characteristics, and system geometry control the fluid behavior, whether in large systems aboard spacecraft, or micro-scale systems on Earth. First, efforts in support of two International Space Station (ISS) experiments …

Effect Of Intake Temperature And Boost Pressure On The Auto-Ignition Of Fuels With Different Cetane Numbers And Volatilities, Chandrasekharan Jayakumar

Wayne State University Dissertations

The aim of this research is to investigate the effect of air inlet temperature and boost pressure on the auto-ignition of fuels that have different CNs and volatilities in a single cylinder diesel engine. The inlet air temperature is varied over a range of 30°C to 110°C at a constant intake pressure of 1.1 bar. The boost pressure is varied from 1.1 bar to 1.5 bar at a constant intake temperature of 60°C. All engine tests are run at steady-state conditions. The fuels used are ultra-low-sulfur-diesel (ULSD), JP-8 (two blends with CN 50 & 31) and F-T SPK. Detailed analysis …

Exergetic Analysis Of Hydrogen Combustion Involving Electronically Excited Species, Devon Alan Washington

Wayne State University Dissertations

Plasma-assisted combustion (PAC) is a growing field of research that involves using nonthermal plasma (NTP) to enhance combustion. PAC research involves modeling reaction mechanisms and chemical kinetics. Exergy analysis of combustion devices focuses on combustion irreversibility, including mixing, internal heat transfer, and oxidation. This novel research project merges these two branches of research.

The focus of this work is the application of exergy analysis to PAC systems, to analyze the effect introducing NTP has on trends in exergy destruction associated with oxidation during hydrogen combustion. This was accomplished by developing a plug flow reactor model using the chemical simulation tool …

Self-Healing Of Ionomeric Polymers With Carbon Fibers From Medium-Velocity Impact And Resistive Heating, Vishnu Baba Sundaresan, Andrew Morgan, Matt Castellucci

Mechanical and Nuclear Engineering Publications

Self-healing materials science has seen significant advances in the last decade. Recent efforts have demonstrated healing in polymeric materials through chemical reaction, thermal treatment, and ultraviolet irradiation. The existing technology for healing polymeric materials through the aforementioned mechanisms produces an irreversible change in the material and makes it unsuitable for subsequent healing cycles. To overcome these disadvantages, we demonstrate a new composite self-healing material made from an ionomer (Surlyn) and carbon fiber that can sustain damage from medium-velocity impact and heal from the energy of the impact. Furthermore, the carbon fiber embedded in the polymer matrix results in resistive heating …

A Scr Model Based On Reactor And Engine Experimental Studies For A Cu-Zeolite Catalyst, Xiaobo Song

Dissertations, Master's Theses and Master's Reports - Open

A NO_x reduction efficiency higher than 95% with NH₃ slip less than 30 ppm is desirable for heavy-duty diesel (HDD) engines using selective catalytic reduction (SCR) systems to meet the US EPA 2010 NO_x standard and the 2014-2018 fuel consumption regulation. The SCR performance needs to be improved through experimental and modeling studies. In this research, a high fidelity global kinetic 1-dimensional 2-site SCR model with mass transfer, heat transfer and global reaction mechanisms was developed for a Cu-zeolite catalyst. The model simulates the SCR performance for the engine exhaust conditions with NH₃ maldistribution and aging …

Co-Electrophoretic Deposition Of Liquid Metal And Silicon For Lithium-Ion Battery Application, Hanfei Zhang

Dissertations, Master's Theses and Master's Reports - Open

A low cost electrophoretic deposition (EPD) process was successfully used for liquid metal thin film deposition with a high depositing rate of 0.6 µ/min. Furthermore, silicon nano-powder and liquid metal were then simultaneously deposited as the negative electrode of lithium-ion battery by a technology called co-EPD. The liquid metal was hoping to act as the matrix for silicon particles during lithium ion insertion and distraction. Half-cell testing was performed using as prepared co-EPD sample. An initial discharge capacity of 1500 mAh/g was reported for nano-silicon and galinstan electrode, although the capacity fading issue of these samples was also observed.

Experimental Investigation Of Regular Fluids And Nanofluids During Flow Boiling In A Single Microchannel At Different Heat Fluxes And Mass Fluxes, Zachary Edel

Dissertations, Master's Theses and Master's Reports - Open

The dissipation of high heat flux from integrated circuit chips and the maintenance of acceptable junction temperatures in high powered electronics require advanced cooling technologies. One such technology is two-phase cooling in microchannels under confined flow boiling conditions. In macroscale flow boiling bubbles will nucleate on the channel walls, grow, and depart from the surface. In microscale flow boiling bubbles can fill the channel diameter before the liquid drag force has a chance to sweep them off the channel wall. As a confined bubble elongates in a microchannel, it traps thin liquid films between the heated wall and the vapor …

Thermal Characterization Of A Gasoline Turbocharged Direct Injection (Gtdi) Engine Utilizing Lean Operation And Exhaust Gas Recirculation (Egr), Daniel P. Madison

Dissertations, Master's Theses and Master's Reports - Open

The push for improved fuel economy and reduced emissions has led to great achievements in engine performance and control. These achievements have increased the efficiency and power density of gasoline engines dramatically in the last two decades. With the added power density, thermal management of the engine has become increasingly important. Therefore it is critical to have accurate temperature and heat transfer models as well as data to validate them. With the recent adoption of the 2025 Corporate Average Fuel Economy(CAFE) standard, there has been a push to improve the thermal efficiency of internal combustion engines even further. Lean and …

Aerodynamics Of Biplane Wind Turbine Blades, Phillip K. Chiu

Link Foundation Energy Fellowship Reports

Little is known about the aerodynamics of biplane wind turbine blades. Even more fundamentally, the two-dimensional aerodynamics of thick biplane airfoils are not well-understood. Supported by the Link Foundation Energy Fellowship, this research has sought to develop a better understanding of these aerodynamics through wind tunnel experiments and computational fluid dynamics. An understanding of biplane aerodynamics is a key step towards the commercial implementation of biplane wind turbine blades. These designs could enable larger turbines designs, ultimately reducing the cost of wind-generated electricity and helping to displace conventional means of electricity generation.

Hybrid Position And Impedance Control Of A Forging Process, Derek Stake

ETD Archive

"Pick and place" robotic material handling has been a key to increase piece rates and reduced variability in forging processes. One of the drawbacks to current "pick and place" robotic material handling methods is the inability to locate the part after a forging operation and move it to the next position in a timely manner. If the billet changes position during the forging process, the manipulator will take longer to find the part and transfer it to the next station or the manipulator will be unable to move the part to the next position correctly which may cause scrap. Another …

On Applications And Limitations Of One-Dimensional Capillarity Formulations For Media With Heterogeneous Wettability, T. M. Bucher, H. Vahedi Tafreshi

Mechanical and Nuclear Engineering Publications

Force-balance-based one-dimensional algebraic formulations that are often used in characterizing the capillarity of a multi-component system (e.g., predicting capillary height rise inporous media) are discussed. It is shown that such formulations fail to provide accurate predictions when the distribution of wetting (or non-wetting) surfaces is not homogeneous. A more general mathematical formulation is suggested and used to demonstrate that for media with heterogeneous wettability, hydrophilic (or hydrophobic) surfaces clustered in groups will have less contribution to the overall capillarity of the system.

A Multi-Objective Optimal Pid Control For A Nonlinear System With Time Delay, Furui Xiong, Zhichang Qin, Carlos Hernández, Yousef Sardahi, Yousef Narajani, Wei Liang, Yang Xue, Oliver Schütze, Jianqiao Sun

All Engineering Faculty Research

It is generally difficult to design feedback controls of nonlinear systems with time delay to meet time domain specifications such as rise time, overshoot, and tracking error. Furthermore, these time domain specifications tend to be conflicting to each other to make the control design even more challenging. This paper presents a cell mapping method for multi-objective optimal feedback control design in time domain for a nonlinear Duffing system with time delay. We first review the multi-objective optimization problem and its formulation for control design. We then introduce the cell mapping method and a hybrid algorithm for global optimal solutions. Numerical …

Examining Design Fixation In Engineering Idea Generation: The Role Of Example Modality, Vimal Viswanathan, Julie Linsey

Faculty Publications, Mechanical Engineering

Design fixation is a major concern in engineering idea generation because it restricts the solution space in which designers search for their ideas. For designers to be more creative, it is essential to mitigate their fixation. The majority of studies in the literature investigate the role of pictorial stimuli in design fixation; however, the role of examples presented in other formats, including physical prototypes, is largely unknown. This paper presents a study that compares design fixation, in novice designers, caused by pictorial and physical representations. The effects of defixating materials proposed by Linsey et al. (2010) are also investigated. The …

Modeling Tools For Conformal Orthotic Devices, Steven David Riddle

Open Access Theses

The purpose of this thesis is to advance the design of conformal orthotic devices through the development of two modeling tools to address knowledge gaps in the field.

The field of human orthotics has been continually troubled by identifying successful methods of harnessing devices to the body. Past orthotics have utilized a rigid framework with minimal degrees of freedom (DOFs) driven by hard actuators attached to the body at select anchor points. Many devices design the structure and anchor points such that they reduce the degrees of freedom of a targeted joint, limiting the user's mobility and often causing the …

Characterization Of Heat And Mass Transport In Magnesium Hydride Hydrogen Storage Systems, Jennifer Anne Dadson

Open Access Theses

Hydrogen systems can provide viable alternatives for satisfying the world's energy requirements that both reduce dependency on and are more environmentally friendly than fossil fuels. For vehicular systems for example, hydrogen storage systems must have adequate gravimetric and volumetric storage capacities in addition to rapid uptake and release. Magnesium hydride shows good potential as a solid state hydrogen storage media due to its high gravimetric storage capacity of 7.6 wt% H₂; the highest of all reversible metal hydrides. Drawbacks, however, are its large reaction enthalpy of 78 kJ/mol for the desorption reaction and its low thermal conductivity of …

Control Of Impacting Dynamical Systems, Akhil Salunke

Open Access Theses

Impacting systems are encountered frequently in nature, and often in mechanical systems. Impacts can be undesirable in some applications, and desirable and deliberate in others. A subset of impacting systems are vibro&ndashimpact systems, wherein the impacts arise during vibrations or oscillatory behavior. Considering their potential prominence in a number of day&ndashto&ndashday applications, such vibro&ndashimpact systems have become the subject of extensive research in the past few decades. A significant number of these studies have been specifically aimed at controlling vibro&ndashimpact systems. To date, a wide variety of control algorithms have been proposed, a subset of which account for the effects …

Examination Of Thermal Properties Of Carbon-Carbon And Graphitized Carbon-Carbon Composites, Melanie Jene' Patrick

Theses

Thermal characterization of composites is essential for their proper assignment to a specific application. Specific heat, thermal diffusivity, and thermal conductivity of carbon-carbon composites are essential in the engineering design process and in the analysis of aerospace vehicles, space systems and other high temperature thermal systems. Specifically, thermal conductivity determines the working temperature levels of a material and is influential in its performance in high temperature applications. There is insufficient thermal property data for carbon-carbon composites over a range of temperatures. The purpose of this research is to develop a thermal properties database for carbon-carbon composites that will contain in-plane …

Me-Em 2012-13 Annual Report, Department Of Mechanical Engineering-Engineering Mechanics, Michigan Technological University

Department of Mechanical and Aerospace Engineering Annual Reports

Table of Contents

• Research Centers
• Students
• Faculty & Staff
• Alumni
• Contracts & Grants
• Publications

Thermal Characterization Of As4/3501-6 Carbon-Epoxy Composite, Bradley R. Doleman

Theses

Thermal diffusivity, specific heat, and thermal conductivity are important thermophysical properties of composite materials and foams. Thermal characterization provides these material properties which play a significant role in the engineering design process of space systems, aerospace vehicles, transportation, energy storage devices, and power generation including fuel cells. Thermal conductivity is the parameter that is important in problems involving heat transfer and thermal structures. Because it determines the working temperature levels of a material, the thermal conductivity is critical when considering the performance of materials in high temperature applications as well as safety, process control, and quality assurance. As a result …

Transient And Quasi-Steady Thermal Behaviour Of A Building Envelope Due To Retrofitted Cavity Wall And Ceiling Insulation, Aimee Byrne, Gerard Byrne, Anna Davies, Anthony Robinson

Articles

Accurate understanding of the thermal behaviour of building components is essential for predicting heat-ing or cooling needs and facilitates the implementation of more successful energy saving strategies and retrofits. This paper focuses on a specific measure commonly introduced through the residential energy efficiency retrofit programmes in Ireland–insulation. Traditionally, assessments of the performance of building envelopes have been based on assumed thermal resistances of the materials involved, labora-tory tests and computer modelling. The aim of the present work is to investigate the in situ thermal behaviour of a case study building and its components under transient and quasi-steady environmental conditions, comparing …

Modeling And Hardware-In-The-Loop Simulation Of Power-Split Hybrid Electric Vehicles, Shreyash Joshi

Dissertations, Master's Theses and Master's Reports - Open

Conventional vehicles are creating pollution problems, global warming and the extinction of high density fuels. To address these problems, automotive companies and universities are researching on hybrid electric vehicles where two different power devices are used to propel a vehicle. This research studies the development and testing of a dynamic model for Prius 2010 Hybrid Synergy Drive (HSD), a power-split device. The device was modeled and integrated with a hybrid vehicle model. To add an electric only mode for vehicle propulsion, the hybrid synergy drive was modified by adding a clutch to carrier 1. The performance of the integrated vehicle …

Multiscale Modeling Of Liquid Crystalline/Nanotube Composites, Sharil Patrale

Dissertations, Master's Theses and Master's Reports - Open

The objective of this research is to synthesize structural composites designed with particular areas defined with custom modulus, strength and toughness values in order to improve the overall mechanical behavior of the composite. Such composites are defined and referred to as 3D-designer composites. These composites will be formed from liquid crystalline polymers and carbon nanotubes. The fabrication process is a variation of rapid prototyping process, which is a layered, additive-manufacturing approach. Composites formed using this process can be custom designed by apt modeling methods for superior performance in advanced applications. The focus of this research is on enhancement of Young's …