Solder Joint Design Optimization Of Quad-Flat Package With Gullwing Leads Under Accelerated Thermal Cycling And Power Cycling,
2018
University of Texas at Arlington
Solder Joint Design Optimization Of Quad-Flat Package With Gullwing Leads Under Accelerated Thermal Cycling And Power Cycling, Pranav Nikam
Mechanical and Aerospace Engineering Theses - Archive
Ever growing complexity in designing of Integrated Circuits and accommodating high number of Interconnections in the device is the main source of motivation in today’s world of IC devices. Quad Flat Package (QFP) with Gullwing leads is spearhead technology which enables high connectivity levels required to be customized in most convenient and advantageous form. Gullwing leads have the advantage of having a large area in contact with solder and also work as mechanical springs. They also make it easier to inspect and rework. Lot of work has been carried out on inspecting the reliability of solder joints in QFP packages …
Experimental And Numerical Investigation Of Heat Transfer In Battery Pack Of A Hoverboard,
2018
University of Texas at Arlington
Experimental And Numerical Investigation Of Heat Transfer In Battery Pack Of A Hoverboard, Abhinav Prasad
Mechanical and Aerospace Engineering Theses - Archive
Li-ion cells are used for energy storage and conversion in electric vehicles and a variety of consumer devices such as hoverboards. Performance and safety of such devices is severely affected by overheating of Li-ion cells in aggressive operating conditions. Several accidents due to fire in the battery pack of a hoverboard have been reported in the recent past. Despite the large number of hoverboards in use worldwide, there is a lack of systematic research on heat transfer in battery packs of hoverboards. This study presents experimental and numerical analysis of heat transfer in Li-ion battery pack of a hoverboard to …
Study Of The Effect Of Humidity On Thermal Cycling Of A Ball Grid Array (Bga) Package,
2018
University of Texas at Arlington
Study Of The Effect Of Humidity On Thermal Cycling Of A Ball Grid Array (Bga) Package, Samuel Terrence Ambosta
Mechanical and Aerospace Engineering Theses - Archive
Thermal Cycling (TC) Test is one of the most important reliability tests in the packaging and semiconductor industry. Humidity on the other hand is one of the significant factors for the reliability of packages, since there are several failures due to moisture absorption in packages. Humidity in packages can lead to soften them and decrease adhesive strength resulting into delamination near the solder tip and wire bond joint, which results in poor electric performance as well as reduced mechanical reliability. In addition, decrease in adhesive strength also causes corrosion in that area which leads to package failure. Absorption of humidity …
Comparison Of Steel And Composite Rail Axle By Finite Element Analysis,
2018
University of Texas at Arlington
Comparison Of Steel And Composite Rail Axle By Finite Element Analysis, Samip Nikulbhai Shah
Mechanical and Aerospace Engineering Theses - Archive
Axles are one of the most important railway vehicle parts that supports the weight of both vehicle and passenger. Failure in Axle in its operating condition may cause heavy damage to the passenger and car as well, hence high strength design is required to mitigate the possibilities of axle failure. Generally steel axle is used in rail industry, nowadays there are more interest to replace steel axle to the composite axle. Use of advanced composite material such as Kevlar, graphite-fiber, carbon-fiber and glass-fiber with proper resin core resulted in remarkable achievements because of its specific strength and improve fatigue, specific …
Trust Based Time-Varying Network Topology For Distributed Co-Operative Control Of Multi-Class Multi-Agent Systems,
2018
University of Texas at Arlington
Trust Based Time-Varying Network Topology For Distributed Co-Operative Control Of Multi-Class Multi-Agent Systems, Ankur Vipulkumar Dalal
Mechanical and Aerospace Engineering Theses - Archive
With increased levels of autonomy in most of the engineering fields and booms in areas such as swarms, platoons and Internet of Things (IoT), communication and information flow has become a highly researched field. With advancements in autonomous vehicles (AVs) and drones in armed warfare, more and more focus is being laid on intercommunication between these vehicles and its surroundings as well as intra-communication among the fleets/swarms itself. It is easier to deal with individual agents whereas it is quite challenging to deal with multi-agent systems especially with highly dynamic agents. In this thesis, we propose a general protocol for …
Dynamics And Control Of Jumping Legged Robot,
2018
University of Texas at Arlington
Dynamics And Control Of Jumping Legged Robot, Gurashish Singh
Mechanical and Aerospace Engineering Theses - Archive
This research aims to studying the agility of legged robots particularly their interactions with the ground and achieve a jumping motion by using an operational space controller. Methods were developed to first formulate the equations of motions of the full system. Then we used the published impact and contact analytical framework to detect simultaneous, indeterminate impact and transition to contact with friction and addressed the well-known issues with energy consistency when using rigid body models for dynamic systems (i.e. there are no unusual gains in the energy after impact has ended). Non-penetration of the ground was achieved through online constraint …
Characterization Of A Cold Plate By Experimental Analysis And Power Savings Calculation Of Dynamic Cold Plate,
2018
University of Texas at Arlington
Characterization Of A Cold Plate By Experimental Analysis And Power Savings Calculation Of Dynamic Cold Plate, Barath Ragul Manimaran
Mechanical and Aerospace Engineering Theses - Archive
Cooling is a critical part of data center’s infrastructure, and with ongoing demands in data processing and storage, thermal management issues are of great concern. Some imperative methods of removing heat are either using air or liquid (preferably water or refrigerant). When high power densities modules are involved, liquid cooling addresses some of the problems faced by air cooling as liquid coolants have higher thermal capacitance. Also, in the case of multi-chip modules, a non-uniform heating due to multicore generates hotspots and increases temperature gradients across the module. A dynamic cold plate was developed to address these issues with the …
Monitoring Calcification In Rigid Wet Cooling Media Used In Direct Evaporative Cooling Of Data Centers.,
2018
University of Texas at Arlington
Monitoring Calcification In Rigid Wet Cooling Media Used In Direct Evaporative Cooling Of Data Centers., Hemanth Narayan Dakshinamurthy
Mechanical and Aerospace Engineering Theses - Archive
Rigid wet cooling media is a key component of direct and indirect evaporative cooling systems. Evaporation is the process of a substance in a liquid state changing to a gaseous state. When water evaporates only H2O molecules gets evaporated and the other chemicals in the water is left behind on the surface as residue. Soul concentration is to determine how calcium scale affects the overall performance i.e. saturation efficiency and pressure drop across the media pad. An Accelerated Degradation Testing by rapid wetting and drying on the media pads at elevated levels of calcium was planned on the media pad. …
Thermal Degradation Of Passive Components For Use In Single Phase Immersion Cooling Application,
2018
University of Texas at Arlington
Thermal Degradation Of Passive Components For Use In Single Phase Immersion Cooling Application, Keerthivasan Padmanaban
Mechanical and Aerospace Engineering Theses - Archive
The growth in the computing and data industry demands high-performance data centers where the thermal management issues are of greater concern. A cooling system paradigm using the immersion cooling technology is a more reliable and effective method. In immersion cooling, servers are directly submerged into a dielectric fluid. A comparative study on the reliability of the passive components cooled by air, mineral oil and EC-100 was carried out. The Accelerated Thermal Cycling test based on ATC JEDEC is applicable only for air cooling. The ASTM standards D 3455 with some suitable modification was adopted to test the material compatibility with …
Measurement Of The Thermal Performance Of A Single-Phase Immersion Cooled Server At Elevated Temperatures For Prolonged Time,
2018
University of Texas at Arlington
Measurement Of The Thermal Performance Of A Single-Phase Immersion Cooled Server At Elevated Temperatures For Prolonged Time, Pratik Vithoba Bansode
Mechanical and Aerospace Engineering Theses - Archive
Fully immersion of servers in electrically non-conductive (dielectric) fluid has recently become a promising technique for minimizing cooling energy consumption in data centers. The improved thermal properties of these dielectric fluids facilitate considerable savings in both upfront and operating cost over traditional air-cooling. This technology provides an opportunity for accommodating increased power densities. It also minimizes and addresses the common operational issues of air cooling methods like overheating and temperature swing in the system, fan failures, dust, air quality, and corrosion. This paper presents various data about the performance of a fully single-phase dielectric fluid immersed server over wide temperature …
Computational Fluid Dynamics Simulation-Based Artificial Neural Network Modelling For Data Center Cooling Prediction,
2018
University of Texas at Arlington
Computational Fluid Dynamics Simulation-Based Artificial Neural Network Modelling For Data Center Cooling Prediction, Nikita Ravindra Sukthankar
Mechanical and Aerospace Engineering Theses - Archive
Continuous provision of quality supply air to data center’s IT pod room is key parameter in assuring effective data center operation without any down time. Due to number of possible operating conditions and non-linear relations between operating parameters make the working mechanism of data center difficult to optimize energy use. At present industries are using computational fluid dynamics (CFD) to simulate thermal behaviour for all types of operating conditions. The focus of this study is to predict Supply Air Temperature using Artificial Neural Network(ANN) which can overcome limitations of CFD such as high cost, need of expertise and large computation …
Cfd Analysis Of Thermal Shadowing And Optimization Of Heat Sinks In 3rd Generation Open Compute Server For Single Phase Immersion Cooling Applications,
2018
University of Texas at Arlington
Cfd Analysis Of Thermal Shadowing And Optimization Of Heat Sinks In 3rd Generation Open Compute Server For Single Phase Immersion Cooling Applications, Ravya Dandamudi
Mechanical and Aerospace Engineering Theses - Archive
In today’s networking world, utilization of servers and data center has been increasing significantly. Increasing demands of processing and storage of data causes corresponding increase in power density of servers. The data center energy efficiency largely depends on thermal management of servers. Currently, air cooling is the most widely used thermal management technology in data centers. However, air cooling is starting to reach its limits due to very high-powered microprocessors and packaging. To overcome the limitations of air cooling in data centers, operators are moving towards immersion cooling using different dielectric fluids. Thermal shadowing is the effect in which temperature …
Analysis And Comparison Between A Conventional Metal And A Metal-Composite Marine Propeller Shaft,
2018
University of Texas at Arlington
Analysis And Comparison Between A Conventional Metal And A Metal-Composite Marine Propeller Shaft, Kaushal Mayankkumar Shah
Mechanical and Aerospace Engineering Theses - Archive
The basic principal of a ship propulsion is the reactive (thrust) force generated by the propellers against the stream of water which forces the ship to propel in the opposite direction. The Shafting system is thus required to transmit the necessary torque to the propeller at a certain speed. Studies have suggested that shafts are the most common reason of failures among the whole marine propulsion system comprising of the main engine and propeller apart from the shaft. Stress concentration and torsional vibrations are the two major causes of failure in the propulsion shafting systems based on the case study …
Comparison Of Steel And Composite Leaf Springs Using Fea,
2018
University of Texas at Arlington
Comparison Of Steel And Composite Leaf Springs Using Fea, Prashik Sunil Gaikwad
Mechanical and Aerospace Engineering Theses - Archive
Composite materials are widely used in aeronautical, marine and automotive industries, because of their excellent mechanical properties, low density and ease of manufacture. Due to this increasing trend to utilize composite materials, it has become necessary to investigate the pros and cons of composites. Increasing competition and innovation in automobile sector tends to modify the existing products by new and advanced material products. A suspension system of vehicle is also an area where these innovations are carried out regularly. Leaf springs are one of the oldest suspension components that are being still used widely in automobiles. They contribute to 15-20% …
Experimental Analysis Of The Effects Of Single-Phase Immersion Cooling Of Optical Interconnects On Mechanical Properties Of Active Optical Cables,
2018
University of Texas at Arlington
Experimental Analysis Of The Effects Of Single-Phase Immersion Cooling Of Optical Interconnects On Mechanical Properties Of Active Optical Cables, Hrishabh Singh
Mechanical and Aerospace Engineering Theses - Archive
Active optical cables (AOC) are being increasingly adopted for data communication and storage, networking, and high-performance computing (HPC) applications. However, their ability to meet higher data-rate requirements necessitates increased heat dissipation demands in fiberoptic datacom systems. Many dielectric coolants having heat capacities much higher than that of air are available in the market. However, there is a lack of literature and data on the reliability of using single-phase dielectric fluids for immersion-cooling of inter and intra-rack optical interconnections in data centers. Industry standards and prevalent aging test methods for optical cables prove insufficient as they do not address immersion in …
Design And Optimization Of Mixed Ionic-Electronic Conductive Material For Use In Solid Oxide Fuel Cell Utilizing Carbon Nanotubes,
2018
University of Texas at Arlington
Design And Optimization Of Mixed Ionic-Electronic Conductive Material For Use In Solid Oxide Fuel Cell Utilizing Carbon Nanotubes, Shiuan Duo Chiang
Mechanical and Aerospace Engineering Theses - Archive
Triple phase boundary (TPB) is considered to be an important limiting factor of the fuel cell performance. Triple phase boundary is a geometrical line where the ionic, electronic and gaseous fuel phase of the fuel cell comes in contact. Electrochemical reactions of the fuel cell occur at the TPB sites. The TPB length greatly impacts the efficiency of the fuel cells. Carbon nanotubes have recently been shown to enhance oxygen reduction reaction (ORR) of the fuel cell and transfer electrons with its conductive properties. CNT also provides porosity in the electrode and could facilitate mass transport. CNT allows for oxygen …
Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges,
2018
University of Texas at Arlington
Finite Element Analysis And Design Improvement Of Aerospace Composite Hinges, Gaurang Girish Sonpal
Mechanical and Aerospace Engineering Theses - Archive
Hinges are the most commonly used mechanical bearings to connect 2 objects for relative rotational motion. Modern day aerospace hinges are generally made using either Aluminum, Steel or bronze. The study analyzes the use of composite material as an alternative to traditional materials for manufacturing these hinges. The research is focused on the Finite element Analysis of a composite hinge as well as an aluminum hinge. The load capacity of both the types of hinges are compared. To improve the design of the composite hinge, a combination of composite material and aluminum is used to model a hybrid hinge design. …
General Methods For The Thermal Design Of Data Centers Based On Evaporative Cooling,
2018
University of Texas at Arlington
General Methods For The Thermal Design Of Data Centers Based On Evaporative Cooling, Raghvendra Parinam
Mechanical and Aerospace Engineering Theses - Archive
With the increasing load on the servers, the cost and energy required to cool a data center has been on the rise. This has kept the researchers to explore more efficient and economical cooling technologies for data centers. One such technology is evaporative cooling. The evaporative cooling systems are one of the most effective methods available for cooling the data centers. So, developing the generic methods for the thermal design of data centers is of utmost importance. This research aims to identify, develop and validate the thermal model for Direct Evaporative Cooling and Indirect Evaporative Cooling. By taking the environmental …
Psychrometric Bin Analysis For Data Center Cooling Modes Using Artificial Neural Networks,
2018
University of Texas at Arlington
Psychrometric Bin Analysis For Data Center Cooling Modes Using Artificial Neural Networks, Abhishek Uday Walekar
Mechanical and Aerospace Engineering Theses - Archive
With an increase in the need for energy efficient data centers, a lot of research is being done to increase the use of Air Side Economizers (ASEs), Direct Evaporative Cooling (DEC), Indirect Evaporative Cooling (IEC) and multistage I/DEC cooling. The cooling strategies used to control these systems is based on typical meteorological year (TMY) weather data and thermodynamic principles. But the main drawback of these control strategies is that they do not account for the nonlinearities developed by the conditions inside the data center. So, the primary objective of this study is to use Artificial Neural Networks (ANN) for predicting …
Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle,
2018
University of Texas at Arlington
Comparison Of Cross-Sectional Profiles For Side Impact Crash Structure In Passenger Vehicle, Nitish Sharma
Mechanical and Aerospace Engineering Theses - Archive
Car’s safety is most important structural criteria while designing an automotive chassis. To protect the occupants from a direct impact, the passenger cabin and the structure of the vehicle should have an appropriate stiffness so that the it absorbs any kind of impact and keeps the passenger safe. Design standards are set by various vehicle safety association around the world based on different crash situations i.e. front crash, side impact, roll over etc. Among these standards, side impact crash account for over all 40% crashes all around the world and is one of the most fatal crash scenarios. This research …
