Mechanical Engineering Commons^™

Surface Location Error In Robotic Milling: Modeling And Experiments, Richard Henry Swan Jr.

Masters Theses

Robotic milling offers new opportunities for discrete part manufacturing as an alternative to milling using large conventional machine tools. The advantage of industrial robots is their large work volume, configurability, and comparatively low cost. However, robots are significantly less stiff than conventional machine tools, which can lead to poor surface finish, low machining accuracy, and low material removal rates. The purpose of this research is to predict the geometric errors, or surface location errors, that occur in a robotic mulling tool path, validate these predictions with machining tests, and compensate these errors by tool path modification. Compared with conventional machine …

Design Of Machine Tool Cross Beam Using Metal Big Area Additive Manufacturing, Tyler Poon

Masters Theses

The modern world would not be what it is now without machine tools. Advances in materials and processes, such as carbon fiber and additive manufacturing (AM), enable the design space for machine tool components to expand. However, machine tool components require accurate geometry, which is not available from parts produced by metal Big Area Additive Manufacturing (mBAAM). This project outlines the process in which a traditionally manufactured machine tool component, a welded box structure on an existing machine tool, was redesigned to be made using mBAAM. The goal was to design a structure that was printable using the MedUSA system …

Assessing Mechanical Performance Of Dissimilar Steel Systems Made Via Wire-Arc Additive Manufacturing, Obed Daniel Acevedo

Masters Theses

Hot stamping is part of a specific type of metalworking procedure widely used in the automotive industry. This research seeks to help make hot stamp tooling component production more cost-effective by using large-scale additive manufacturing. Additive manufacturing can produce dissimilar steel components that can be more cost-effective and time-efficient and allow for complex geometries to be made. A dissimilar steel system consisting of 410 martensitic stainless steel and AWS ER70S-6 mild steel is proposed to make hot stamps, making them more cost-efficient. However, the material interface's mechanical behavior in 410SS-mild steel additively manufactured material systems is not well understood. This …

Correlating Fracture Toughness And Surface Roughness For A Ductile Epoxy Adhered To Aluminum Substrates, Kurt Ryan Smith

Masters Theses

Adhesively bonded joints are used across multiple disciplines as an efficient and cost effective method for reinforcing, repairing, or creating new structures. Sufficient understanding of the bond line characteristics of the adhesive is necessary to properly design a reliable bonded joint and ensure a long service life. It is well understood that surface preparation has a significant impact on these interface characteristics as a given level of surface roughness achieves mechanical interlocking between the resin and metal and is important to prevent premature interfacial failure [1]. The goal of this study is to characterize the fracture toughness values for an …

Determination Of Chemical Notch, KChem On Aluminum And Steel When Subjected Under Slow Strain Rate Test In Corrosive Environment, Joshua Teo Lee Kuok

Masters Theses

When designing for any mechanical components or system, the question would arise as to how the material would react to the loads subjected on it? Would the component survive its service load? How would it react to environmental corrosion? To answer these questions, the technique used in this thesis paper is the Slow Strain Rate Test (SSRT) method. Aluminum and steel were chosen as the material to be tested in this paper. Al 7075-T651, and Al 6061-T651 was chosen due to its wide range of application, high strength to weight ratio and ease of machinability. It is highly used in …

Investigation Of Discrete Element Methods For Stud To Turf Interactions, Justin Rittenhouse

Masters Theses

Artificial turf is frequently used in sports today and attempts to advantageously replicate a natural grass/soil playing surface. Despite numerous advantages, the technology is correlated with an increase in injuries. The concept behind this research is to create and validate a discrete element model (DEM) for the ground/foot interaction through the use of open source software. After validation, the goal is to analyze an arrangement of studs to determine what role stud geometry plays on torque [N-mm] and force [N] generation. The validation data was provided through laboratory experiments. Three football studs attached to a rigid bracket were turned at …

Design Of A Robotic Instrument Manipulator For Endoscopic Deployment, Ryan Ponten

Masters Theses

This thesis describes the initial design process for an application of continuum robotics to endoscopic surgical procedures, specifically dissection of the colon. We first introduce the long-term vision for a benchtop dual-instrument endoscopic system with intuitive haptic controllers and then narrow our focus to the design and testing of the instrument manipulator itself, which must be actuated through the long, winding channel of a standard colonoscope.

Based on design requirements for a target procedure, we analyze simulations of two types of continuum robots using recently established kinematic and mechanic modeling approaches: the concentric-tube robot (CTR) and the concentric agonist-antagonist robot …

Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, David Leon Yoder

Masters Theses

Wind tunnel test customers continue to push the limits by producing air vehicle designs that produce high aerodynamic loads at the desired test conditions. These loads are a combination of steady aerodynamic, unsteady aerodynamic, and inertial forces. A methodology to monitor the health of a wind tunnel strain-gage balance has been developed. The objective of this methodology is to define the stress limits of the balance and monitor these limits so the balance can be safely tested without failure of the balance. A balance failure could result in costly damage to the wind tunnel model, support system, and the wind …

Development, Analysis, And Optimization Of A Swirl-Promoting Mean Flow Solution For Solid Rocket Motors, Andrew Steven Fist

Masters Theses

This work demonstrates and analyses a new flow candidate for describing the internal gaseous motion in simulated rocket motors. The fundamental features of this solution include the conservation of key system properties also incorporated in the classic Taylor-Culick (TC) system (i.e. inviscid, axisymmetric, steady and rotational properties), while allowing for the development of a swirling velocity component. The work compares the new solution to the development and formulation of the classic TC system, ultimately identifying that both the new and classic solutions are special cases of the Bragg-Hawthorne equation. Following this development, the text then explores the development of energy-optimized …

Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, Trenton Bush

Masters Theses

When a solid, ductile particle impacts a substrate at sufficient velocity, the resulting heat, pressure, and plastic deformation can produce bonding at the interface. The use of a supersonic gas flow to accelerate such particles is known as Cold Spray deposition. The Cold Spray process has been commercialized for some metallic materials, but further research is required to unlock the exciting material properties possible with polymeric compounds. In this work, a combined computational and experimental study a) simulated and optimized the nozzle flow conditions necessary to produce bonding in a polyethylene particle, b) developed and fabricated an experimental device, and …

Rotordynamic Analysis Of A Two-Pole Synchronous Motor With Sleeve And Pressure Dam Bearings, Justin Matthew Garrard

Masters Theses

A two-pole synchronous motor was recently rewound for the von Karman Gas Dynamics facility at Arnold Engineering Development Complex, Arnold Air Force Base, Tennessee. After installing the rewound rotor, unexpected vibration amplitudes were recorded during motor checkouts. To resolve this issue, an investigation was initiated to investigate the causes of the vibration issues. The investigation discovered that the original design used sleeve bearings rather than pressure dam bearings. A study was formed to determine the effect of changing the pressure dam bearings back to sleeve bearings. Because only one spare bearing shell existed, the bearing with the highest vibration amplitudes …

Benchmarking Of A Single-Cylinder Engine Toward The Development Of A Direct Fuel-Injection System, Michael J. Nienhuis

Masters Theses

In this study, the performance and efficiency of a single-cylinder gasoline, fourstroke cycle engine was benchmarked in support of the Formula SAE student project. The development of an engine test stand, instrumentation, data acquisition, and test plan is described in detail. Experimental results in the areas of engine performance and efficiency are discussed. Physical test data were used to refine a previous model of a single-cylinder, gasoline, direct-injection engine. Results from this effort are discussed and compared to those obtained in a preliminary study. The current work advances the development of more efficient power-train technologies for application in small displacement …

Use Of A Press-Fit Grip Sleeve For Cable-In-Conduit Superconductor Integration: Effects Of Tensile And Fatigue Loading, Paul Michael Hayes

Masters Theses

Presently, one of the most promising sources for a future of abundant, low-emission, and efficient energy comes in the form of nuclear fusion. However, in order for it to become a reality, fusion technology must overcome the obstacle of plasma confinement. Utilizing the tokomak based design for magnetic plasma confinement; ITER is currently developing a fusion reactor to prove its commercial viability.

The purpose of this research was to determine the feasibility of pulling toroidal field cable with a press-fit grip sleeve that utilizes friction to generate a gripping force. Such a design is being considered by ITER to integrate …

Effect Of Moisture Absorption On The Sinter Quality Of Central Solenoid (Cs) Coil Pack, Zeshaan Sher Mohammed

Masters Theses

Fusion energy has been said to be the solution to all the world’s energy problems. The International Thermonuclear Experimental Reactor (ITER) is the flagship project to demonstrate the feasibility of fusion energy. The Central Solenoid (CS), an important component of the reactor, is needed to induce plasma current, initiate, ramp-up, ramp-down, and sustain plasma in a very controlled manner. In order to achieve this, the CS coil packs must be manufactured under controlled conditions. The CS conductor is an advanced cable-in-conduit Nb3Sn superconductor. The CS cable will be made in long continuous sections but with thousands of meter of cable …

Thermal, Magnetic, And Mechanical Stresses And Strains In Copper/Cyanate Ester Cylindrical Coils – Effects Of Variations In Fiber Volume Fraction, Chance Thomas Donahue

Masters Theses

Several problems must be solved in the construction, design, and operation of a nuclear fusion reactor. One of the chief problems in the manufacture of high-powered copper/polymer composite magnets is the difficulty to precisely control the fiber volume fraction. In this thesis, the effect of variations in fiber volume fraction on thermal stresses in copper/cyanate ester composite cylinders is investigated. The cylinder is a composite that uses copper wires that run longitudinally in a cyanate ester resin specifically developed by Composite Technology Development, Inc. This composite cylinder design is commonly used in magnets for nuclear fusion reactors. The application of …

The Analysis Of Cantilever Plates With Concentrated Loads, Constant Roberts Marks

Masters Theses

(From the Introduction)

The problem of a cantilever plate or slab with variable, discontinuous, concentrated, or eccentric loading occurs frequently in engineering design. Examples are substructure walls, piers, projecting floor slabs, and gear teeth. The solution of most of these problems can be made to depend on the analysis of the plate in question loaded with one or more concentrated loads. Such analyses are available for only a few cases of loading, and no practical method is available to the designer for making any kind of a reasonably accurate stress analysis for many cases he may encounter.

In …