Structural Optimization & Reliability Of 3d Package By Studying Crack Behavior On Tsv & Beol & Impact Of Power Cycling On Reliability Flip Chip Package,
2017
University of Texas at Arlington
Structural Optimization & Reliability Of 3d Package By Studying Crack Behavior On Tsv & Beol & Impact Of Power Cycling On Reliability Flip Chip Package, Unique Rahangdale
Mechanical and Aerospace Engineering Theses - Archive
The 3D packaging is stacked of chips on top of another which is emerging as a powerful technology that satisfies such integrated circuit (IC) package demands. Most of the stress develops at interfaces and the interface delamination of TSV may encounter which is mainly driven by a shear stress concentration at the point. In this study, the effect of package structure on the failure metric of the 3D package has been studied. J-integral has been used to quantify the crack driving force. The crack is modeled at the TSV and BEOL (Back End of the Line) and the die -substrate …
Design Optimization Of Race Car Steering Knuckle For Additive Manufacturing,
2017
University of Texas at Arlington
Design Optimization Of Race Car Steering Knuckle For Additive Manufacturing, Yobani Martinez
Mechanical and Aerospace Engineering Theses - Archive
Additive manufacturing enables increased geometric complexity in structural configuration compared with conventional manufacturing methods. A Physics-first Computer Aided engineering (CAE) process beginning with structural topology optimization enables engineers to take advantage of this increased geometric design freedom. This work develops and demonstrates the steps and tools necessary to realize complex design configuration for additive manufactured. This report looks at the race car steering knuckle using the UTA FSAE upright as a case study. The stiffness driven upright component design is executed using topology optimization and NURBS based surface modeling tools. The topology optimization model is developed for 3 different load …
Thermal Management Of High Power Multi Chip Module By Design Optimization Of Segregated Serpentine Flow Cold Plate,
2017
University of Texas at Arlington
Thermal Management Of High Power Multi Chip Module By Design Optimization Of Segregated Serpentine Flow Cold Plate, Krishna Chaitanya Siripurapu
Mechanical and Aerospace Engineering Theses - Archive
Data center environment cooling requirements became a challenge with rapid increasing microprocessor power densities which leads to non-uniform distribution of temperature. A practical cooling solution which relies on the segregated flow of cooling resources based on power density for thermal management of high power equipment is introduced. This minimizes energy consumption of cooling infrastructure. Performance of existing cold plate is previewed and amount of savings possible is shown from numerical analysis of segregated model. Model is designed by considering manufacturing feasibility to make samples for proposed solution for future experimental study. A multi-chip module is chosen as a base for …
Numerical And Analytical Study Of Curvature Effects In Laminar Shock Wave/Boundary Layer Interactions,
2017
University of Texas at Arlington
Numerical And Analytical Study Of Curvature Effects In Laminar Shock Wave/Boundary Layer Interactions, James Ray Grisham
Mechanical and Aerospace Engineering Dissertations - Archive
Shock wave/boundary-layer interactions (SBLIs) are one of the most complex flow phenomena because of the different types of physics involved (i.e., viscous versus inviscid) and their side effects such as boundary layer separation and extreme localized heating. Control surfaces based on compliant mechanisms are becoming a reality and introduce an additional variable into the already complex SBLI, namely surface curvature. The purpose of the present work is to systematically study the effects of surface curvature on laminar, ramp-induced SBLIs. This is accomplished using numerical and theoretical approaches in the form of numerical solutions to the compressible Navier–Stokes equations and triple-deck …
Development Of An Advanced Geometry Toolkit Framework For Fitting Complex Topology-Optimized Mesh Structures,
2017
University of Texas at Arlington
Development Of An Advanced Geometry Toolkit Framework For Fitting Complex Topology-Optimized Mesh Structures, Harshit Girishkumar Jani
Mechanical and Aerospace Engineering Theses - Archive
Additive Manufacturing is playing a significant role in developing complex geometries which are not possible by conventional Manufacturing Processes. Topology optimization is playing key a role in deciding conceptual design for additive manufacturing. The output of topology optimization is rough and noisy surfaces. Fitting these surfaces poses challenging task to a designer as it is a tedious and a time-consuming process. The main aim of this research is to automate the process of smoothing noisy meshes. In this research work, I have developed algorithms in MATLAB to create NURBS (Non-Uniform B-Spline) surface patches from given a set of control points. …
A Parametric Study On Thermal Mixing Of Ambient Air And Return Air Streams In A Mixing Chamber Of A Data Center Cooling,
2017
University of Texas at Arlington
A Parametric Study On Thermal Mixing Of Ambient Air And Return Air Streams In A Mixing Chamber Of A Data Center Cooling, Pavan Vijaykumar Kaulgud
Mechanical and Aerospace Engineering Theses - Archive
Thermal Mixing of ambient air and return air streams in a mixing chamber for data center cooling Keywords: Data center cooling, Air side economization, Mixing chamber geometry Pavan Kaulgud, Dr. Dereje Agonafer Air side economization is an arrangement of duct, damper and automatic control system which together allow to introduce outside air to reduce or eliminate the mechanical cooling during mild or cold weather. In this process ambient air is drawn inside from environment, passed through filter to get rid of contaminants and then is introduced to the cold aisle of data center. According to ASHRAE, use of air side …
Finite Element Analysis Of Composite Aircraft Fuselage Frame,
2017
University of Texas at Arlington
Finite Element Analysis Of Composite Aircraft Fuselage Frame, Aditya Milind Dandekar
Mechanical and Aerospace Engineering Theses - Archive
Composites have been introduced in aircraft industries, for their stronger, stiffer, and lighter properties than their metal-alloys counterparts. The general purpose of an aircraft is to transport commercial or military payload. Aircraft frames primarily maintains the shape of fuselage and prevent instability of the structure. Fuselage is similar as wing in construction which consist of longitudinal elements (longerons and stringers), transverse elements (frames and bulkheads) and its external skin. The fuselage is subjected to forces such as the wing reactions, landing gear reaction, empennage reaction, inertia forces subjected due to size and weight, internal pressure forces due to high altitude. …
Steady State And Transient Analytical Modelling Of Non-Uniform Convective Cooling Of A Microprocessor Chip Due To Jet Impingement,
2017
University of Texas at Arlington
Steady State And Transient Analytical Modelling Of Non-Uniform Convective Cooling Of A Microprocessor Chip Due To Jet Impingement, Swapnil D. Luhar
Mechanical and Aerospace Engineering Theses - Archive
Heat removal from microprocessor chips with multiple regions of dynamic heat generation remains a critical technological challenge. Excessive temperature rise is undesirable for performance as well as reliability. Jet impingement cooling has been widely investigated as a potential thermal management technique due to the capability of localized cooling and of dynamically following the heat generation distribution. A jet offers large local convective heat transfer coefficient, for which theoretical models and correlations have been proposed for a variety of scenarios. However, not much work exists on using this information to determine the resulting temperature distribution. This work addresses this need by …
Manufacturing And Characterization Of A 3d-Printable, Antibacterial, Magnesium Oxide Nanoparticles Reinforced Abs Filament,
2017
University of Texas at Arlington
Manufacturing And Characterization Of A 3d-Printable, Antibacterial, Magnesium Oxide Nanoparticles Reinforced Abs Filament, Saket Thapliyal
Mechanical and Aerospace Engineering Theses - Archive
This research work consists of two phases. In phase one it is intended to manufacture an antibacterial 3D printable filament by extruding a solid state mixture of (MgO) nanoparticles (NPs) and Acrylonitrile Butadiene Styrene (ABS) pellets. A single screw extruder was used to extrude ABS pellets containing 0, 0.5, 1, 2 and 4 wt. % MgO NP. This phase deals with manufacturing and testing the filament for mechanical properties, antibacterial properties and 3D printability. On one hand tensile strength, ductility and 3D-printabiliy were observed to decrease with increasing concentrations of MgO NP in ABS matrix, on the other hand the …
Numerical Analysis Of A Flapping Elliptic Flat Plate In Hover: A Study Of Leading Edge Vortex Dynamics,
2017
University of Texas at Arlington
Numerical Analysis Of A Flapping Elliptic Flat Plate In Hover: A Study Of Leading Edge Vortex Dynamics, C. Vivek Nair
Mechanical and Aerospace Engineering Theses - Archive
Flapping flight is an area of research that is gaining a lot of prominence in engineering, especially with the increase in interest in applying the flapping mechanism of natural fliers to small scale MAVs. The ongoing contributions to this field include studies finding optimal wing shape, flap frequency, and flap trajectories. Flapping flight is an unsteady aerodynamic mechanism, and consists of 3 interactive forces: delayed stall, rotational circulation, and wake capture. The dominant lift generating mechanism is the leading edge vortex (LEV). Natural fliers optimize their flap to gain maximize LEV stability. For our research we simulate 2 cases of …
Experimental And Computational Study Of The Acclimation Of New It Equipment,
2017
University of Texas at Arlington
Experimental And Computational Study Of The Acclimation Of New It Equipment, Neil Johnson Vazhappilly
Mechanical and Aerospace Engineering Theses - Archive
Acclimation of newly commissioned IT equipment is an important step that is necessary for safe operations. Proper acclimation is required to prevent an unnecessary condensation from forming and causing premature failure in the equipment. Acclimation is particularly important in cold weather shipping where the component or server reaches the destination well below the destination data center’s dew point, resulting in moisture and condensate. Operating the equipment before it acclimates might cause damage, while waiting too long for the equipment to acclimate might cost companies expensive computational time. This study tries to address the issue by studying the various factors that …
Flexsar Bistatic And Monostatic Circular Sar Collection,
2017
Space Dynamics Laboratory
Flexsar Bistatic And Monostatic Circular Sar Collection, Chad Knight, Mark Jensen, Trevor Jewkes, Jacob Gunther
Space Dynamics Laboratory Publications
Bistatic SAR data has advantages and disadvantages compared to monostatic data. This papers examines a combined bistatic and monostatic SAR data collection. The airborne platform used a monostatic radar system with two transmit and two receive channels in a pulsed spotlight mode. Another receive-only system was placed on an elevated mountaintop. The mountaintop receive system had two receive channels. The airborne asset flew in a full circle around several targets, exercising a large range of bistatic geometries. Various SAR modes were collected, including single-channel, quad-channel, and along-track interferometry (ATI) data for monostatic and bistatic modalities. This paper focuses on the …
Influence Of Relative Density And Microstructural Anisotropy On The Global Elastic Properties Of Cellular Structures,
2017
University of Texas at Arlington
Influence Of Relative Density And Microstructural Anisotropy On The Global Elastic Properties Of Cellular Structures, Justin Compton
Mechanical and Aerospace Engineering Theses - Archive
The favorable strength-to-weight ratio of cellular solids makes them ideal for structural applications. With the advent of additive manufacturing, the fabrication of complex cellular structures is becoming a reality. It is therefore necessary to understand the mechanical properties of cellular structures. The global mechanical properties of cellular structures are governed by geometry and therefore, differ from the mechanical properties of the base material from which they are constructed. In this study, finite element models are developed to explore the effective elastic properties of honeycomb structures for isotropic and anisotropic microstructural material properties. Finite element models are generated for regular, hexagonal …
Refurbished And 3d Modeled Thermal Vacuum Chamber,
2017
California Polytechnic State University, San Luis Obispo
Refurbished And 3d Modeled Thermal Vacuum Chamber, Lauren M. Glenn
Master's Theses
Spacecraft testing includes acoustics, vibrations, and thermal vacuum. Cal Poly’s Space Environments Lab is equipped with multiple vacuum chambers, but no thermal vacuum chamber. The purpose of this thesis is to incorporate an ATS Chiller system with the HVEC vacuum chamber so students are able to experiment with a thermal vacuum chamber. The ATS Chiller had leaky pipes that needed to be refurbished and a shroud was implemented to improve thermal capabilities of the system. The full system was able to reach temperatures as low as -38ºC and as high as 58ºC at a pressure of 10-6 Torr. The ATS …
Frequency Tuning Of Vibration Absorber Using Topology Optimization,
2017
University of Texas at Arlington
Frequency Tuning Of Vibration Absorber Using Topology Optimization, Swapnil Subhash Harel
Mechanical and Aerospace Engineering Theses - Archive
A tuned mass absorber is a system for reducing the amplitude in one oscillator by coupling it to a second oscillator. If tuned correctly, the maximum amplitude of the first oscillator in response to a periodic driver will be lowered, and much of the vibration will be ’transferred’ to the second oscillator. The tuned vibration absorber (TVA) has been utilized for vibration control purposes in many sectors of Civil/Automotive/Aerospace Engineering for many decades since its inception. Time and again we come across a situation in which a vibratory system is required to run near resonance. In the past, approaches have …
Numerical Investigation Of Vortex Generator Flow Control For External-Compression Supersonic Inlets,
2017
University of Texas at Arlington
Numerical Investigation Of Vortex Generator Flow Control For External-Compression Supersonic Inlets, Ezgihan Baydar
Mechanical and Aerospace Engineering Dissertations - Archive
Vortex generators (VGs) within external-compression supersonic inlets for Mach 1.6 were investigated to determine their ability to increase total pressure recovery and reduce total pressure distortion. Ramp and vane-type VGs were studied. The geometric factors of interest included height, length, spacing, angle-of-incidence, and positions upstream and downstream of the inlet terminal shock. The flow through the inlet was simulated numerically through the solution of the steady-state, Reynolds-averaged Navier-Stokes equations on multi-block, structured grids using the Wind-US flow solver. The inlet performance was characterized by the inlet total pressure recovery and the radial and circumferential total pressure distortion indices at the …
Intensity Control Of Individual Dbd Plasma Filament. Ii. Fundamental Physical Mechanism,
2017
Missouri University of Science and Technology
Intensity Control Of Individual Dbd Plasma Filament. Ii. Fundamental Physical Mechanism, M. C. Paliwoda, J. L. Rovey
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Filamentary volume dielectric barrier discharge (DBD) produces patterned plasma structures that are currently being explored for reconfigurable metamaterial applications. Previous work has demonstrated control of the presence and intensity of a single DBD plasma filament (within an array of filaments) by biasing a low voltage needle electrode. The results were attributed to redistributed charge inside the DBD due to the modified electric field created by the needle electrode. In the present work, results from a 3D electrodynamic field simulation bolster this argument. Results show that increasing needle bias voltage causes changes in the transverse electric field structure, resulting in redistribution …
Intensity Control Of Individual Dbd Plasma Filament. I. Experiment With A Needle Electrode,
2017
Missouri University of Science and Technology
Intensity Control Of Individual Dbd Plasma Filament. I. Experiment With A Needle Electrode, M. C. Paliwoda, J. L. Rovey
Mechanical and Aerospace Engineering Faculty Research & Creative Works
Filamentary volume dielectric barrier discharge (DBD) produces patterned plasma structures that are currently being explored for reconfigurable metamaterial applications. In this work, the presence and intensity of a single filament (within an array of filaments) are controlled by biasing a low voltage needle electrode by less than 7% of the driving voltage. The current, voltage, and time-averaged normalized light intensity were measured while varying the needle voltage through self-biasing resistors. For a 7.5 kV, 3.2 kHz DBD in air, the needle-controlled filament intensity varies from 80% to 0% of the light intensity of surrounding filaments. When the biased voltage prevents …
Integration Of Macro-Fiber Composite Material On A Low Cost Unmanned Aerial System,
2017
Embry-Riddle Aeronautical University
Integration Of Macro-Fiber Composite Material On A Low Cost Unmanned Aerial System, May Chong Chan
Doctoral Dissertations and Master's Theses
The development, deployment, and operation of Unmanned Aerial Systems (UAS) have grown exponentially in recent years and have provided researchers with the opportunity to gain hands-on experience with aircraft in a manner that was previously limited to institutions and companies with large budgets. This allows the generation and testing of UAS advanced technologies using low cost systems. The scope of this thesis does not aim to make vast improvements to the control strategy itself, but to expand upon previous UAV work carried out at Embry-Riddle by designing, implementing, and demonstrating a simulation environment for mechanical and Macro-Fiber Composite (MFC) actuated …
Performance Analysis Of A Coaxial Helicopter In Hover And Forward Flight,
2017
Embry-Riddle Aeronautical University
Performance Analysis Of A Coaxial Helicopter In Hover And Forward Flight, Stanrich D. Fernandes
Doctoral Dissertations and Master's Theses
The performance of a coaxial rotor system has been analyzed by establishing a proper basis of comparison between a conventional single rotor and coaxial rotor. An attempt has also been made to better understand the complicated aerodynamic interactions associated with coaxial rotor wakes by using a free-vortex methodology (FVM). The FVM is a Lagrangian-based wake convection methodology, which solves for the evolution of the vortical wake produced by the rotor blades under the influence of an external flow. The extent to which the two rotors interact with each other was found to be highly dependent on the inter-rotor spacing. To …
