Mechanical Engineering Commons^™

Effects Of Machining Parameters And Cooling Strategies On Cutting Forces And Surface Integrity In High-Speed Slot End-Milling Of Titanium Alloy, Emenike Chukwuma

Masters Theses

“Paper 1 presents the results of the investigations of the effects of cooling strategies [Emulsion cooling, Minimum Quantity Lubrication (MQL) and Liquid Nitrogen (LN₂)] and machining parameters (feed rate and spindle speed) on cutting force components, cutting temperature and tool wear during slot end-milling of titanium Ti-6Al-4V workpiece. All machining experiments were conducted using four-flute 0.5 inch diameter uncoated solid carbide end-mill on Cincinnati Milacron, Sabre 750 vertical machining center equipped with Acramatic 2100 controller. Cutting force components were acquired and tool wear was indirectly measured from maximum cutting force variation per slot from the first pass to …

Effects Of Machining Parameters On Cutting Forces,Shear Angle And Friction In Orthogonal Turning Of Titanium Alloys, Hilary Onyishi

Masters Theses

“Paper 1 presents the results of the investigations on the effects of machining parameters on cutting forces, shear angle and friction in orthogonal turning of titanium alloy tube. Uncoated fine-grained cemented tungsten carbide (WC/Co) and Physical Vapour Deposition (PVD) TiAlN coated grade turning tool inserts, with 5⁰ and 15⁰ rake angles were used under low and high cutting speeds of 120 and 240m/min, at three different feedrates (0.05, 0.075 and 0.1 mm/rev). The experiments were conducted under flooded coolant to reflect what is practically obtainable in manufacturing industries. The experimental results show that cutting forces at two selected cutting speeds …

Rotary Displacement Piezoelectric Energy Harvester, Headman Sanei

Masters Theses

“This study proposes a novel piezoelectric energy harvester for rotary motion applications. It is based on an annular unimorph plate, mounted on a shaft rotating at a constant angular velocity, under constant amplitude point-wise force. The mathematical model and the analysis was proposed for the inverse problem of a rotating disk under a static stationary force. The disk, however, is assumed to be stationary subjected to a traveling force. The distributed parameter electromechanical equations governing the behavior of the system are provided in closed-form, incorporating both an AC and a simple rectifier circuit. The performance of the energy harvester was …

Manufacturing And Characterization Of Polyurethane Based Sandwich Composites, Stephen Robert Hawkins

Masters Theses

"Composite sandwich structures have been extensively employed in aerospace structures, ship building, infrastructure, etc. due to their light weight and high strength to weight ratio. The understanding of their behavior under impact and environmental conditions is extremely important for the design and manufacturing of these engineering structures since these problems are directly related to structural integrity and safety requirements. Vacuum assisted resin transfer molding (VARTM) is one of the commonly used low cost composite manufacturing processes. Polyurethane (PU) resin system has been observed to have better mechanical properties and higher impact strength when compared to conventional resin systems such as …

Development Of Marker-Based Human Motion Capture Systems For Assembly Simulation And Ergonomic Analysis, Sajeev C. Puthenveetil

Masters Theses

"In aerospace industry, the assembly operator is often exposed to potential ergonomic injuries due to awkward postures while working in confined spaces. Manually generating worker postures in simulation software for ergonomic analysis is cumbersome. This research focuses on the use of marker-based optical motion capture technology to generate human motion simulations in real-time for ergonomic analysis. To address the challenges involved in capturing human motions in a real work environment, an assembly operation was simulated in a four-walled Computer Automated Virtual Environment (CAVE) which provides an immersive 3D environment to the worker performing the assembly operation. Multiple cameras were set-up …

Development Of A New Temporary Fastener For Aerospace Automation, Xiangwen Zhang

Masters Theses

"Temporary fasteners are required in aircraft assembly, especially in the assembly of wings, fuselage, and aircraft skin's substructure prior to drilling holes for permanent fasteners by automated drilling machines. The objective was to develop a temporary fastener that can be installed, clamped, loosened, and removed from one side with a short head length. Published papers, web pages and patents relating to temporary fasteners were reviewed. Then by considering the ability to meet the operation requirements and concerns, a temporary fastener was designed with the following advantages:

• a simple structure that can be easily fabricated
• a short head length to save …

Manufacturing And Performance Evaluation Of Out-Of-Autoclave Sandwich Composites, Sriram Nagarajan

Masters Theses

"Composite sandwich structures are being increasingly employed in applications which require high strength, high in-plane and flexural stiffness coupled with a reduction in weight. Sandwich composites used in the aerospace industry are typically manufactured using high pressure autoclave processing which is expensive and time consuming. A viable low cost alternative is the Out-of-autoclave (OOA) process. One of the most dominant failure modes in sandwich composites is the debonding that occurs at the facesheet skin to core interphase leading to severe degradation of structural properties of the sandwich. A well formed adhesive bond at the skin to core interphase and improved …

Enhancement Of Vortex Induced Vibrations Using Roughness Strips, Ashwin Vinod

Masters Theses

"The current experimental work focuses on studying the effects of surface roughness on vortex induced vibration (VIV) of an elastically mounted circular cylinder which is free to vibrate in a direction transverse to the flow. Flow separation in known to occur due to viscous effects when a fluid flows over a bluff body. The separation of fluid causes shedding of alternating vortices in the downstream region, which in turn impart an alternating force on the bluff body. The vibrations incurred due to such forces are called as Vortex Induced Vibrations (VIV) and have been traditionally known to be harmful to …

Processing Of Continuous Fiber Reinforced Ceramic Composites For Ultra High Temperature Applications Using Organosilicon Polymer Precursors, James Robert Nicholas

Masters Theses

"The current work is on the development of continuous fiber reinforced ceramic materials (CFCCs) for use in ultra high temperature applications. These applications subject materials to extremely high temperatures (> 2000⁰C). Monolithic ceramics are currently being used for these applications, but the tendency to fail catastrophically has driven the need for the next generation of material. Reinforcing with continuous fibers significantly improves the toughness of the monolithic materials; however, this is a manufacturing challenge. The development of commercial, low-viscosity preceramic polymers provides new opportunities to fabricate CFCCs. Preceramic polymers behave as polymers at low temperatures and are transformed into ceramics …

Effects Of Initial Conditions On Rayleigh-Taylor Instability Using Elastic-Plastic Materials, Pamela Susan Roach

Masters Theses

"When an elastic-plastic solid is accelerated by a fluid of lower density, Rayleigh-Taylor instability (RTI) is observed, and the instability is mitigated by the material's mechanical strength, initial conditions, and the acceleration that drives the instability. Such instances of RTI are observed in supernovas, explosive welding, and inertial confinement fusion. In contrast to Newtonian fluids, experimental study of RTI in accelerated solids is traditionally hindered by difficulty to measure material properties and exceedingly small time scales. An understanding of the role initial conditions and material properties have on the growth of RTI will lead to better control of the instability. …

Development Of A Postprocessor For A Multi-Axis Cnc Milling Center, Mihir Satish Adivarekar

Masters Theses

"Most of the current college design and manufacturing curricula are primarily focused on computer aided design (CAD), while less emphasis is given to computer aided manufacturing (CAM). A great opportunity has been missed as the benefits of CAD/CAM cannot then be fully learned. Postprocessor plays a vital role in integration of CAD//CAM with computer numerically controlled (CNC) machines. Hence, postprocessor must be developed accurately. This thesis is composed of one paper. Paper I proposes a novel methodology to determine compensation vectors for the post processor of multi-axis milling center. The new approach that has been implemented in Paper I involves …

A Generalized Approach For Compliant Mechanism Design Using The Synthesis With Compliance Method, With Experimental Validation, Ashish B. Koli

Masters Theses

"Compliant mechanisms offer numerous advantages over their rigid-body counterparts. The synthesis with compliance technique synthesizes compliant mechanisms for conventional rigid-body synthesis tasks with energy/torque specifications at precision positions. In spite of its usefulness, the method suffers from some limitations/problems. The purpose of this work is to investigate these sensitivities with the synthesis with compliance technique and improve upon existing method. A new, simple but efficient, method for synthesis with compliance using an optimization approach is proposed, and its usefulness and simplicity demonstrated over the existing method. The strongly and weakly coupled system of kinematic and energy/torque equations in the existing …

A Friction Prediction Model For Small Si Engines, Avinash Singh

Masters Theses

"A substantial portion of the input fuel energy in an SI engine is lost towards overcoming the frictional forces from various rubbing parts. These frictional losses are very significant in small engines and these losses can be reduced by incorporating some design changes. A semi-empirical friction prediction model was studied and modified with the help of the experimental results for small SI engines. This model is dependent upon engine geometry and speed. The model divides the frictional work into different sub-assemblies of the engine and these sub-assemblies are in turn divided to determine the friction associated with individual components. A …

Dynamic Contact Analysis Of A Piezoelectrically Driven Ultrasonic Crawler-Actuator, Dwight Santiago Maness

Masters Theses

"A standing wave ultrasonic motor (SWUM) is presented in this thesis. The actuator is piezoelectrically powered and operates in the first and second bending modes to move forwards and backwards, respectively. The kinematic stability of the crawler, backed by experimental results is shown in the first paper presented in this thesis. This study demonstrates that in the absence of a preload or kinematic constraints, the crawler shows vertical stability. A full transient analysis using the finite element method is performed characterizing the speed and contact variables is conducted in the second paper. The results show that given enough time the …

Paste Development And Co-Sintering Test Of Zirconium Carbide And Tungsten In Freeze-Form Extrusion Fabrication, Ang Li

Masters Theses

"Ultra-high temperature ceramics are being investigated for future use in aerospace applications due to their superior thermo-mechanical properties, as well as oxidation resistance, at temperatures above 2000°C. However, their brittle properties make them susceptible to thermal shock failure. Components fabricated as functionally graded materials (FGMs) can combine the superior properties of ceramics with the toughness of an underlying refractory metal by fabricating graded composites. This paper discusses the grading of two materials through the use of a Freeze-form Extrusion Fabrication (FEF) system to build FGMs parts consisting of zirconium carbide (ZrC) and tungsten (W). Aqueous-based colloidal suspensions of ZrC and …

Development Of A Methodology For Pseudo-Rigid-Body Models Of Compliant Segments With Inserts, And Experimental Validation, Raghvendra Sharadchandra Kuber

Masters Theses

"Compliant mechanisms have shown a great deal of potential in the last few decades in providing better solutions to design problems with numerous benefits; however, their use has been limited due to current challenges in the material selection. With ever increasing focus on the applications of compliant mechanisms, it is necessary to find alternatives to the existing materials and methods of prototyping. The purpose of this work is to develop a methodology for pseudo-rigid-body models of compliant segments with compliant inserts, comprised of a resilient material placed between the layers of a softer material, to alleviate any creep and strength …

Transmission Shaft Design For Hydrokinetic Turbine With Reliability Consideration, Goutham Pusapati

Masters Theses

"Hydrokinetic energy, a relatively new kind of renewable energy, can be generated from flowing water in rivers or oceans. Hydrokinetic turbines (HKTs) are a major system for hydrokinetic energy, and the reliability of the HKTs is critical for both their lifecycle cost and safety. The objective of this work is to apply advanced methodologies of reliability analysis and reliability-based design to the transmission shaft design for a horizontal-axis, non-submerged HKT. The deterministic shaft design is performed first by considering failure modes of strength and deflection using distortion energy, maximum shear and deflection theories. Then the reliability analysis of the shaft …

Water Management Capabilities Of Bio-Inspired Flow Field Configurations For Polymer Electrolyte Membrane Fuel Cells, Nicholas Warren Freer

Masters Theses

"Fuel cells have received an increasing amount of attention over the past decade for their power production capabilities. Polymer electrolyte membrane (PEM) fuel cells in particular are researched because of their high power density, large range of operating conditions, green products, and ease of scalability. PEM fuel cells do have a number of issues that reduce their overall performance. These issues include variations in reactant distribution, materials issues for the bipolar plate, and flooding caused by poor water management. Variations in the reactant distribution causes lower overall power output due to regions of low reactant density. This means that optimizing …

Analysis Of Laminated Anisotropic Plates And Shells Via A Modified Complementary Energy Principle Approach, Martin Claude Domfang

Dissertations (1934 -)

The present work is concerned with the finite element structural analysis of laminated anisotropic plates and shells. New elements based on a modified complementary energy principle are proposed to improve the analysis of such composite structures. Third order deformation plate and shell models incorporating a convergence parameter are developed to govern the general displacement field.

An eight-node isoparametric quadrilateral element with two independent cross-sectional rotations and three normal displacements is utilized to describe the displacement field. The present modified complementary energy formulation incorporates a number of in-plane strain functions of various orders. The corresponding in-plane stresses for each lamina are …

Ankle Impedance And Ankle Angles During Step Turn And Straight Walk: Implications For The Design Of A Steerable Ankle-Foot Prosthetic Robot, Evandro M. Ficanha

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

During locomotion, turning is a common and recurring event which is largely neglected in the current state-of-the-art ankle-foot prostheses, forcing amputees to use different steering mechanisms for turning, compared to non-amputees. A better understanding of the complexities surrounding lower limb prostheses will lead to increased health and well-being of amputees. The aim of this research is to develop a steerable ankle-foot prosthesis that mimics the human ankle mechanical properties. Experiments were developed to estimate the mechanical impedance of the ankle and the ankles angles during straight walk and step turn. Next, this information was used in the design of a …

Novel Automotive Waste Heat Recovery Techniques, John Randall Armstead

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

The United States transportation industry is predicted to consume approximately 13 million barrels of liquid fuel per day by 2025. If one percent of the fuel energy were salvaged through waste heat recovery, there would be a reduction of 130 thousand barrels of liquid fuel per day. This dissertation focuses on automotive waste heat recovery techniques with an emphasis on two novel techniques.

The first technique investigated was a combination coolant and exhaust-based Rankine cycle system, which utilized a patented piston-in-piston engine technology. The research scope included a simulation of the maximum mass flow rate of steam (700 K and …

An Experimental Investigation Into The Effects Of Biodiesel Blends On Particulate Matter Oxidation In A Catalyzed Particulate Filter During Active Regeneration, James Pidgeon

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

Active regeneration experiments were carried out on a production 2007 Cummins 8.9L ISL engine and associated DOC and CPF aftertreatment system. The effects of SME biodiesel blends were investigated in this study in order to determine the PM oxidation kinetics associated with active regeneration, and to determine the effect of biodiesel on them. The experimental data from this study will also be used to calibrate the MTU-1D CPF model. Accurately predicting the PM mass retained in the CPF and the oxidation characteristics will provide the basis for computation in the ECU that will minimize the fuel penalty associated with active …

Molecular Modeling Of Pmr-15 Polyimide, Fnu Pruthul Kokkada Ravindranath

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

PMR-15 polyimide is a polymer that is used as a matrix in composites. These composites with PMR-15 matrices are called advanced polymer matrix composite that is abundantly used in the aerospace and electronics industries because of its high temperature resistivity. Apart from having high temperature sustainability, PMR-15 composites also display good thermal-oxidative stability, mechanical properties, processability and low costs, which makes it a suitable material for manufacturing aircraft structures. PMR-15 uses the reverse Diels-Alder (RDA) method for crosslinking which provides it with the groundwork for its distinctive thermal stability and a range of 280-300 degree Centigrade use temperature. Regardless of …

Two-Phase Flow In Microchannels: Morphology And Interface Phenomena, Alexandru Herescu

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

The existence and morphology, as well as the dynamics of micro-scale gas-liquid interfaces is investigated numerically and experimentally. These studies can be used to assess liquid management issues in microsystems such as PEMFC gas flow channels, and are meant to open new research perspectives in two-phase flow, particularly in film deposition on non-wetting surfaces. For example the critical plug volume data can be used to deliver desired length plugs, or to determine the plug formation frequency. The dynamics of gas-liquid interfaces, of interest for applications involving small passages (e.g. heat exchangers, phase separators and filtration systems), was investigated using high-speed …

Dynamic Model Based State Estimation In A Heavy Duty Diesel Aftertreatment System For Onboard Diagnostics And Controls, Harsha S. Surenahalli

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

Estimating un-measurable states is an important component for onboard diagnostics (OBD) and control strategy development in diesel exhaust aftertreatment systems. This research focuses on the development of an Extended Kalman Filter (EKF) based state estimator for two of the main components in a diesel engine aftertreatment system: the Diesel Oxidation Catalyst (DOC) and the Selective Catalytic Reduction (SCR) catalyst. One of the key areas of interest is the performance of these estimators when the catalyzed particulate filter (CPF) is being actively regenerated.

In this study, model reduction techniques were developed and used to develop reduced order models from the 1D …

Reverse Engineering The Structural And Acoustic Behavior Of A Stradivari Violin, Michael A. Pyrkosz

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

There is a tremendous amount of mystery that surrounds the instruments of Antonio Stradivari. There have been many studies done in the past, but no one completely understands exactly how he made his instruments, or why they are still considered the best in the world. This project is designed to develop an engineering model of one of Stradivari's violins that will accurately simulate the structural and acoustic behavior of the instrument. It also hopes to shine some light on what makes the instruments of Stradivari unique when compared to other violins. It will focus on geometry and material properties, utilizing …

High Voltage Electrophoretic Deposition For Electrochemical Energy Storage And Other Applications, Sunand Santhanagopalan

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

High voltage electrophoretic deposition (HVEPD) has been developed as a novel technique to obtain vertically aligned forests of one-dimensional nanomaterials for efficient energy storage. The ability to control and manipulate nanomaterials is critical for their effective usage in a variety of applications. Oriented structures of one-dimensional nanomaterials provide a unique opportunity to take full advantage of their excellent mechanical and electrochemical properties. However, it is still a significant challenge to obtain such oriented structures with great process flexibility, ease of processing under mild conditions and the capability to scale up, especially in context of efficient device fabrication and system packaging. …

Experimental Investigation Into Particulate Matter Distribution In Catalyzed Particulate Filters Using A 3d Terahertz Wave Scanner, Ryan Kristopher Foley

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

The particulate matter distribution (PM) trends that exist in catalyzed particulate filters (CPFs) after loading, passive oxidation, active regeneration, and post loading conditions are not clearly understood. These data are required to optimize the operation of CPFs, prevent damage to the CPFs caused by non-uniform distributions, and develop accurate CPF models. To develop an understanding of PM distribution trends, multiple tests were conducted and the PM distribution was measured in three dimensions using a terahertz wave scanner. The results of this work indicate that loading, passive oxidation, active regeneration, and post loading can all cause non-uniform PM distributions. The density …

Development Of A 1-D Catalyzed Diesel Particulate Filter Model For Simulation Of The Performance And The Oxidation Of Particulate Matter And Nitrogen Oxides Using Passive Oxidation And Active Regeneration Engine Experimental Data, Kiran Premchand

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

Back-pressure on a diesel engine equipped with an aftertreatment system is a function of the pressure drop across the individual components of the aftertreatment system, typically, a diesel oxidation catalyst (DOC), catalyzed particulate filter (CPF) and selective catalytic reduction (SCR) catalyst. Pressure drop across the CPF is a function of the mass flow rate and the temperature of the exhaust flowing through it as well as the mass of particulate matter (PM) retained in the substrate wall and the cake layer that forms on the substrate wall. Therefore, in order to control the back-pressure on the engine at low levels …

Comparative Analysis Of Efficiency And Operating Characteristics Of Automotive Powertrain Architectures Through Chassis Dynamometer Testing, Jeremy J. Anderson

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

The thesis "COMPARATIVE ANALYSIS OF EFFICIENCY AND OPERATING CHARACTERISTICS OF AUTOMOTIVE POWERTRAIN ARCHITECTURES THROUGH CHASSIS DYNAMOMETER TESTING" was completed through a collaborative partnership between Michigan Technological University and Argonne National Laboratory under a contractual agreement titled "Advanced Vehicle Characterization at Argonne National Laboratory". The goal of this project was to investigate, understand and document the performance and operational strategy of several modern passenger vehicles of various architectures. The vehicles were chosen to represent several popular engine and transmission architectures and were instrumented to allow for data collection to facilitate comparative analysis. In order to ensure repeatability and reliability during testing, …