The Limits & Effects Of Draw On Properties And Morphology Of Pan-Based Precursor And The Resultant Carbon Fibers, 2017 University of Kentucky
The Limits & Effects Of Draw On Properties And Morphology Of Pan-Based Precursor And The Resultant Carbon Fibers, Sarah Edrington
Theses and Dissertations--Mechanical Engineering
The process, structure, and property relationship of PAN fiber as a precursor to carbon fiber was studied. The limitations of stable spinning and property improvement associated with hot draw in solution spinning were found and quantified. Conditions were varied to generated precursor fiber up to the limit of draw, from which actual samples were collected for thermal conversion to carbon fiber. Samples of PAN and subsequent carbon fiber were characterized using tensile testing and x-ray analysis. The effects of draw on modulus and break stress, as well as the orientation of the crystalline structure of both parent precursor and resultant …
Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, 2017 University of Kentucky
Shape Memory Behavior Of Dense And Porous Niti Alloys Fabricated By Selective Laser Melting, Soheil Saedi
Theses and Dissertations--Mechanical Engineering
Selective Laser Melting (SLM) of Additive Manufacturing is an attractive fabrication method that employs CAD data to selectively melt the metal powder layer by layer via a laser beam and produce a 3D part. This method not only opens a new window in overcoming traditional NiTi fabrication problems but also for producing porous or complex shaped structures. The combination of SLM fabrication advantages with the unique properties of NiTi alloys, such as shape memory effect, superelasticity, high ductility, work output, corrosion, biocompatibility, etc. makes SLM NiTi alloys extremely promising for numerous applications.
The SLM process parameters such as laser power, …
Numerical Computation Of Transient Response Of 2d Wedge Impact, 2016 University of New Orleans
Numerical Computation Of Transient Response Of 2d Wedge Impact, Naresh Kumar Koyyapu
University of New Orleans Theses and Dissertations
The diverse applications of advanced marine craft ascribed to their high speed and technological advancements has led to the use of stronger and lighter metals in such crafts. High speed, in effect also increases slamming loads as higher speed increases frequency of wave encounter while operating in waves. The present study is limited to wedge impact models. Fundamentally, the study is thus about two-dimensional (2D) wedge impact in water. In an attempt to predict the structural response to impact hydrodynamic force, a beam element based finite element (FE) computer program is written and the results of the code are presented …
Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, 2016 University of Maine
Microstructural Analysis Of Thermoelastic Response, Nonlinear Creep, And Pervasive Cracking In Heterogeneous Materials, Alden C. Cook
Electronic Theses and Dissertations
This dissertation is concerned with the development of robust numerical solution procedures for the generalized micromechanical analysis of linear and nonlinear constitutive behavior in heterogeneous materials. Although the methods developed are applicable in many engineering, geological, and materials science fields, three main areas are explored in this work. First, a numerical methodology is presented for the thermomechanical analysis of heterogeneous materials with a special focus on real polycrystalline microstructures obtained using electron backscatter diffraction techniques. Asymptotic expansion homogenization and finite element analysis are employed for micromechanical analysis of polycrystalline materials. Effective thermoelastic properties of polycrystalline materials are determined and compared …
Final Design Report: Polymer Fatigue Characterization Test Method, 2016 California Polytechnic State University, San Luis Obispo
Final Design Report: Polymer Fatigue Characterization Test Method, Wyatt Ayling, Tyler Price, Brandon Stell, Michela Upson
Mechanical Engineering
Polylogix is a team dedicated to the design, build, and testing of a fatigue machine to simulate cyclic loading on a biomedical polymer. This project is sponsored by Endologix, Inc. to provide test data characterizing mechanical material properties of various formulations of polymer used in abdominal aortic aneurysm surgeries. With this project goal, the machine must be able to test the polymer at body conditions; these include a testing temperature of 37°C and a cycling frequency ranging from 1 Hz to 10 Hz. This report proposes the following solution to this design challenge: an AC motor-driven mechanism utilizing a planetary …
3-Axis Automated Probe Traverse For Aerodynamic Testing, 2016 California Polytechnic State University, San Luis Obispo
3-Axis Automated Probe Traverse For Aerodynamic Testing, Tananant Boonya-Ananta, Ricky Wai, Zander Oostman, Teyvon Brooks
Mechanical Engineering
Our primary objective is to design, build, and test an automated traverse to hold measurement probes in Cal Poly’s low speed wind tunnel. The device should cause minimal flow disturbance. It’s movements must be able to cover eighty percent of the three-dimensional test section. The device should have a mounting point for interchangeable probes. The assembly is to be integrated with the current frame structure on the wind tunnel test section, and should allow very minimal deflection of the measurement probe. The user should be able to control the motion of the traverse via a computer interface which supports automatic …
Analysis Of Composite Plates By Using Mechanics Of Structure Genome And Comparison With Ansys, 2016 Purdue University
Analysis Of Composite Plates By Using Mechanics Of Structure Genome And Comparison With Ansys, Banghua Zhao
Open Access Theses
Motivated by a recently discovered concept, Structure Genome (SG) which is defined as the smallest mathematical building block of a structure, a new approach named Mechanics of Structure Genome (MSG) to model and analyze composite plates is introduced. MSG is implemented in a general-purpose code named SwiftComp™, which provides the constitutive models needed in structural analysis by homogenization and pointwise local fields by dehomogenization. To improve the user friendliness of SwiftComp™, a simple graphic user interface (GUI) based on ANSYS Mechanical APDL platform, called ANSYS-SwiftComp GUI is developed, which provides a convenient way to create some common SG models or …
A Sharp Interface Isogeometric Strategy For Moving Boundary Problems, 2016 Purdue University
A Sharp Interface Isogeometric Strategy For Moving Boundary Problems, Tao Song
Open Access Dissertations
The proposed methodology is first utilized to model stationary and propagating cracks. The crack face is enriched with the Heaviside function which captures the displacement discontinuity. Meanwhile, the crack tips are enriched with asymptotic displacement functions to reproduce the tip singularity. The enriching degrees of freedom associated with the crack tips are chosen as stress intensity factors (SIFs) such that these quantities can be directly extracted from the solution without a-posteriori integral calculation.
As a second application, the Stefan problem is modeled with a hybrid function/derivative enriched interface. Since the interface geometry is explicitly defined, normals and curvatures can be …
Dynamic Monitoring And Life Prediction Of Internal Strain-Gage Balances, 2016 University of Tennessee, Knoxville
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, 2016 University of Tennessee, Knoxville
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 …
Finite Element Simulation Of Pzt-Aided Interrogation Of Composite Laminates Exhibiting Damage, 2016 The British University in Egypt
Finite Element Simulation Of Pzt-Aided Interrogation Of Composite Laminates Exhibiting Damage, Amany Micheal, Yehia Bahei-El-Din
Centre for Advanced Materials
Piezoelectricity has proved effective in capturing changes in structures caused by various damage mechanisms. In one approach, piezoelectric wafer active sensors (PWAS) are mounted on the surface of the host structure and utilized as both actuators and sensors to interrogate the structure and monitor its health. This is achieved by subjecting the PWAS to a transient electric pulse and reading the resulting voltage. Changes in the stiffness of the substrate due to structural damage affect the response of the PWAS, which could be correlated to integrity of the structure. Applying this technique to fibrous composite laminates encounters particular challenges due …
Quantifying And Mapping Induced Strain In Canvas Paintings Using Laser Shearography, 2016 Winterthur Museum, Garden and Library
Quantifying And Mapping Induced Strain In Canvas Paintings Using Laser Shearography, Philip Klausmeyer, Matthew Cushman, Ivo Dobrev, Morteza Khaleghi, Ellery Harrington, Xiaoran Chen, Cosme Furlong
Morteza Khaleghi
High Altitude Ballooning And The Effect Of Temperature On Balloon Ascent Rate, 2016 Hopkinsville Community College
High Altitude Ballooning And The Effect Of Temperature On Balloon Ascent Rate, Christopher D. Young
Posters-at-the-Capitol
Abstract
High Altitude Ballooning and The Effect of Temperature on Balloon Ascent Rate.
Christopher Young
High-altitude balloons are unmanned balloons, usually filled with helium or hydrogen, that after release, ascend into the stratosphere, generally attaining an altitude of between 60,000 to 100,000 feet. The balloon payload includes scientific experiments on organisms, equipment to study radiation, temperature, ultra- violet radiation, and pressure. The balloon flights and experiments are logged by means of video devices and are tracked from the ground through multiple tracking devices. The effect of temperature on the ascent rate of the balloon could change how the balloon expands …
Cold Gas Dynamic Spray – Characterization Of Polymeric Deposition, 2016 University of Massachusetts Amherst
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 …
Collapse Resistance Of Moment Resisting Frame And Shear Wall Rc Structural Systems Exposed To Blast, 2016 Wayne State University
Collapse Resistance Of Moment Resisting Frame And Shear Wall Rc Structural Systems Exposed To Blast, Alaa I. Chehab, Christopher D. Eamon, Joshua Griffin
Civil and Environmental Engineering Faculty Research Publications
Various characteristics of a structure influence its response when subjected to a blast load. This has important implications for survivability and resistance to progressive collapse. In this study, the effect of the type of lateral load resisting system on reinforced concrete building resistance to progressive collapse when exposed to blast load is examined. Fourteen different reinforced concrete structures were considered for analysis, with five structures designed as moment resisting frames and nine designed as shear walls systems. Buildings with 3, 6, and 10 stories with 3, 4, and 5-bay symmetric configurations were considered. The structures were exposed to external and …
Study On The Impact Abrasive Wear Of New Super-High Manganese Steel, 2016 Henan University of Science and Technology
Study On The Impact Abrasive Wear Of New Super-High Manganese Steel, Wenyan Wang
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Numerical And Experimental Characterization Of Material Flow In Forged Aluminum Wheel, 2016 National Chung Cheng University
Numerical And Experimental Characterization Of Material Flow In Forged Aluminum Wheel, Jong-Ning Aoh, Ming-Chiu Li, Chong-Jin Li
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Numerical Modeling And Simulation Of Welding Residual Stresses Using Finite Element Method, 2016 Purdue University
Numerical Modeling And Simulation Of Welding Residual Stresses Using Finite Element Method, Jing Zheng, Ayhan Ince
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Modeling On Tail Pinch In Finishing Rolls During Hot Strip Rolling, 2016 National Chung Cheng University
Modeling On Tail Pinch In Finishing Rolls During Hot Strip Rolling, Jong-Ning Aoh, Han-Kai Hsu, Ming-Fa Chen
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.
Simulation On The Sealing Of Aluminum Ball Joint, 2016 Shanghai Second Polytechnic University
Simulation On The Sealing Of Aluminum Ball Joint, Haobin Tian, Xiaohang Liu, Xuelei Li, Jun Feng
The 8th International Conference on Physical and Numerical Simulation of Materials Processing
No abstract provided.