Mechanical Engineering Commons^™

Parametric Optimization Of Friction Stir Welding Of Aa6061-T6 Samples Using The Copper Donor Stir-Assisted Material Method, Aiman H. Al-Allaq, Joseph Maniscalco, Srinivasa Naik Bhukya, Zhenhua Wu, Abdelmageed Elmustafa

Mechanical & Aerospace Engineering Faculty Publications

This study presents an optimization of the process parameters for the effect of copper (Cu) donor material percentage on the friction stir welding (FSW) of AA6061-T6 alloy. Extensive factorial experiments were conducted to determine the significance of the rotational speed (ω), the transverse speed (v), the interface coefficient of friction (μ), and the Cu donor material percentage in the plunge, left, right, and downstream zones. Design Expert 13 software was used to identify the number of simulation experiments to be conducted using the Abaqus simulation software. From Design Expert 13, which is a thorough multi-objective optimization analysis software, we were …

Study Of Microphonic Effects On The C100 Cryomodule For High Energy Electron Beam Accelerators, Caleb James Hull

Mechanical & Aerospace Engineering Theses & Dissertations

The Continuous Electron Beam Accelerator Facility (CEBAF) at Thomas Jefferson National Laboratory (JLab) is a particle accelerator which can accelerate an electron beam to relativistic speeds and apply the beam onto target samples. The C100 superconducting radio frequency (SRF) cavity is the primary accelerating structure of the C100 cryomodule, one of the many cryomodules which compose the CEBAF linear accelerator. SRF cavities are particularly sensitive to internal and external vibrations that can result in a phenomenon called microphonics which degrade the operational stability of a cryomodule.

The purpose of this thesis is to investigate the significance of mechanical disturbances on …

Recurrence Network Analysis Of Design-Quality Interactions In Additive Manufacturing, Ruimin Chen, Prahalada K. Rao, Yan Lu, Edward W. Reutzel, Hui Yang

Department of Mechanical and Materials Engineering: Faculty Publications

Powder bed fusion (PBF) additive manufacturing (AM) provides a great level of flexibility in the design-driven build of metal products. However, the more complex the design, the more difficult it becomes to control the quality of AM builds. The quality challenge persistently hampers the widespread application of AM technology. Advanced imaging (e.g., X-ray computed tomography scans and high-resolution optical images) has been increasingly explored to enhance the visibility of information and improve the AM quality control. Realizing the full potential of imaging data depends on the advent of information processing methodologies for the analysis of design-quality interactions. This paper presents …

Development Of A Data Acquisition System For Unmanned Aerial Vehicle (Uav) System Identification, Donald Joseph Lear

Mechanical & Aerospace Engineering Theses & Dissertations

Aircraft system identification techniques are developed for fixed wing Unmanned Aerial Vehicles (UAV). The use of a designed flight experiment with measured system inputs/outputs can be used to derive aircraft stability derivatives. This project set out to develop a methodology to support an experiment to model pitch damping in the longitudinal short-period mode of a UAV. A Central Composite Response Surface Design was formed using angle of attack and power levels as factors to test for the pitching moment coefficient response induced by a multistep pitching maneuver.

Selecting a high-quality data acquisition platform was critical to the success of the …

Development Of An Analysis And Design Optimization Framework For Marine Propellers, Ashish C. Tamhane

Mechanical & Aerospace Engineering Theses & Dissertations

In this thesis, a framework for the analysis and design optimization of ship propellers is developed. This framework can be utilized as an efficient synthesis tool in order to determine the main geometric characteristics of the propeller but also to provide the designer with the capability to optimize the shape of the blade sections based on their specific criteria.

A hybrid lifting-line method with lifting-surface corrections to account for the three-dimensional flow effects has been developed. The prediction of the correction factors is achieved using Artificial Neural Networks and Support Vector Regression. This approach results in increased approximation accuracy compared …

The Effect Of Process Parameters And Surface Condition On Bond Strength Between Additively Manufactured Components And Polymer Substrates, Bharat Bhushan Chivukula

Graduate Theses and Dissertations

Additive patching is a process in which printers with multiple axes deposit molten material onto a pre-defined surface to form a bond. Studying the effect of surface roughness and process parameters selected for printing auxiliary part on the bond helps in improving the strength of the final component. Particularly, the influence of surface roughness, as established by adhesion theory, has not been evaluated in the framework of additive manufacturing (AM). A full factorial design of experiments with five replications was conducted on two levels and three factors, viz., layer thickness, surface roughness, and raster angle to examine the underlying effects …

Effect Of Void Fraction On Transverse Shear Modulus Of Advanced Unidirectional Composites, Jui-He Tai

USF Tampa Graduate Theses and Dissertations

In composite materials, transverse shear modulus is a critical moduli parameter for designing complex composite structures. For dependable mathematical modeling of mechanical behavior of composite materials, an accurate estimate of the moduli parameters is critically important as opposed to estimates of strength parameters where underestimation may lead to a non-optimal design but still would give one a safe one.

Although there are mechanical and empirical models available to find transverse shear modulus, they are based on many assumptions. In this work, the model is based on a three-dimensional elastic finite element analysis with multiple cells. To find the shear modulus, …

Improving The Mechanical Performance Of 3d Printed Parts Using Fused Filament Fabrication, Inderpreet Binning

Industrial and Manufacturing Engineering

The 3D printing industry has seen rapid growth in the last 10 years and has been called the next industrial revolution. There are several different processes used in 3D printing, but the most popular process is called Fused Filament Fabrication (FFF) or Fused Deposition Modeling (FDM). This is the process where (most commonly) plastic filament enters a nozzle, is heated to a semi-liquid state, and then deposited into a pattern to create a print. One major drawback to this process is that the prints are anisotropic. This means that the strength of the print varies with the orientation that it …

Machining Strategies Exploring Reduction In Energy Consumption, Abdullah Al Mamun

All Graduate Theses, Dissertations, and Other Capstone Projects

The main aim of this thesis is to explore machining strategies, analyzing energy consumption using Design of Experiments (DOE) at the material removal rate (MRR), compare to cutting geometrical trajectories according to CNC parameters such as spindle RPM, feed rate, depth of cut per pass and total depth of cut. Spindle RPM, depth of cut per pass, and feed rate are selected as the main three factors and each factor has two levels: low-level (-) and high-level (+). These experiments have been performed at an end-milling machine by using a concept of a constant volume of material removal processes in …

A Lab-Scale Experimental Framework For Studying The Phenomenon Of Autorotation, Sigitas Rimkus

Electronic Theses and Dissertations

While wind energy has emerged as a popular source of renewable energy, the traditional wind turbine has an inherent limitation, namely that it only generates power in the presence of sufficiently high and consistent wind speeds. As a result, wind farms are typically built in areas with a high probability of the required wind speeds, which are geographically sparse. One way of overcoming this drawback is to tap into the energy available in winds at high altitudes which are not only consistent and of high magnitude, but also globally pervasive. An airborne wind energy device based upon the phenomenon of …

Selective Laser Sintering; A Design Of Experiments, Philip David Hopkins, Victor Castillo Phd

STAR Program Research Presentations

Additive Manufacturing (AM), also commonly known as 3D Printing or Rapid Prototyping, is a method of manufacturing that provides for the ability to make intricate internal features and easily customizable parts. The concept is to break a Computer Aided Design (CAD) file into a series of thin layers that are sent to the machine and laid down one layer at a time. Just like any other form of processing, material properties can alter by undergoing this process. Manipulating various parameters of the AM process can allow for different properties to be achieved. For this reason, an in depth study will …

Process Optimization Towards The Development Of An Automated Cnc Monitoring System For A Simultaneous Turning And Boring Operation, Manuel Hernandez

Electronic Theses and Dissertations

Manufacturing operations generate revenue by adding value to material through machine work and the cost associated with part production hinders the maximum profit available. In order to remain competitive, companies invest in research to maximize profit and reduce waste of manufacturing operations. This results in cheaper products for the customer without sacrificing quality. The purpose of this research was to identify machine settings of an Okuma LC 40 Turning Center and optimize the cost of machining in terms of tool cost and energy consumption while maintaining part quality at a productive cycle time. Studying the relationship between energy consumption, tool …

Characterizing And Optimizing The Molten Salt Cleaning, Yangyang Long

Theses and Dissertations - UTB/UTPA

Molten salt cleaning is an important cleaning approach in remanufacturing which can remove a variety of contaminants from metal substrates with high efficiency. Facing the very limited research of this approach in literature, this thesis intends to characterize molten salt cleaning process and optimize its parameters when big parts with complicated shapes are cleaned. Based on the development of molten salt cleaning and studies on contaminations, two experiments are conducted. The first one investigates the influences of the hot salts on three metal substrates and shows the applicable of cleaning carbon steel and grey iron parts with molten salt. The …

Uncertainty Analysis And Instrument Selection Using A Web-Based Virtual Experiment, Praveen Malali, Pooja Bais, Robert Choate, Sushil Chaturvedi

Mechanical & Aerospace Engineering Faculty Publications

A methodology has been developed and successfully implemented for transforming physical experiments in an undergraduate thermo-fluids laboratory at Old Dominion University (ODU), a doctoral university, into web-based virtual experiments while the Mechanical Engineering (ME) faculty at Western Kentucky University (WKU), an undergraduate university, have developed and implemented a Design of Experiments (DOE) Plan to assure that graduates of their program have acquired the skills necessary to design and conduct experiments and analyze experimental results. This paper presents details about a web-based virtual experiment designed to teach students about selection of instruments based on the uncertainty estimated from the virtual experiment. …

Experimental And Numerical Investigation Of Tool Heating During Friction Stir Welding, Joshua L. Covington

Theses and Dissertations

The heat input to the tool has been investigated for friction stir welding (FSW) of aluminum alloy AL 7075-T7351 over a wide range of process operating parameters using a combined experimental/numerical approach. In a statistical Design of Experiments fashion, 54 experimental welds (bead-on-plate) were performed at 27 different parameter combinations. Measured outputs during each of the welds included forces in all three coordinate directions and internal temperature of the rotating tool at three locations near the tool/workpiece interface. The heat input to the tool was also identified for each weld using infrared imaging temperature measurement techniques and the portion of …