ASU Electronic Theses and Dissertations
This collection includes most of the ASU Theses and Dissertations from 2011 to present. ASU Theses and Dissertations are available in downloadable PDF format; however, a small percentage of items are under embargo. Information about the dissertations/theses includes degree information, committee members, an abstract, supporting data or media.
In addition to the electronic theses found in the ASU Digital Repository, ASU Theses and Dissertations can be found in the ASU Library Catalog.
Dissertations and Theses granted by Arizona State University are archived and made available through a joint effort of the ASU Graduate College and the ASU Libraries. For more information or questions about this collection contact or visit the Digital Repository ETD Library Guide or contact the ASU Graduate College at gradformat@asu.edu.
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- All Subjects: 19765
- Creators: Bhate, Dhruv
- Creators: Sullivan, Kenneth
Description
The objective of the study was to examine the impact construction document deficiencies have on heavy/civil low-bid infrastructure projects. It encompasses the expertise of 202 heavy/civil construction professionals comprised of contactors and public project owners. The study was designed to determine the frequency and timing of when a contractor discovers construction document deficiencies on heavy/civil low bid projects. The information was correlated with further study data of when a contractor ultimately reports the discovered construction document deficiencies to the public project owner. This research data was compiled and analyzed to determine if contractors are withholding construction document deficiencies from public owners until after the project contract has been executed. The withholding of document deficiencies can benefit contractors by resulting in additional owner incurred costs and potential justification for project time extensions. As a result, further research was required to examine the impact construction document deficiencies have on project cost and schedule. Based on the study findings, it has led to the development of a Contractor Document Review Assessment. The Contractor Document Review Assessment is a risk mitigation device in which contractors and public project owners can identify construction document deficiencies on heavy/civil low-bid construction projects before the project contract has been executed.
ContributorsPesek, Anthony Edward (Author) / Sullivan, Kenneth (Thesis advisor) / Badger, William (Committee member) / Bingham, Evan (Committee member) / Arizona State University (Publisher)
Created2017
Description
Facilities Management (FM) around the globe at different companies in different industries are often forced to make difficult decisions on whether or not to transition a workplace environment and how to decide what factors of a workplace environment can benefit or hinder a company's productivity. The data and research presented within this paper are targeted at aiding and educating FM in determining what factors to consider in a workplace transition to an open-seating design and validate the importance of recognizing how these factors impact the productivity of the individual and the organization. Data contained in this paper was gathered through two different survey samples: 1) a semiconductor company that transitioned its employees from cubicles and offices to an open-seating environment; and 2) a general study open to professionals and their experiences and opinions on workplace environments. This data was used to validate or disprove the views on open-seating workspace held by the FM industry today. Data on the topic of how employees react to being transitioned to open-seating environments and looking at the breakdown of the results between engineers and non-engineers is examined within this research. Also covered within the research is data on transitions to other seating environments outside of open-seating concepts to evaluate and compare transition types. Lastly, data was gathered and discussed on the amount of time needed to adapt after a transition and what environment types were linked to being the most productive. This research provides insight on workplace environments and transitions and how they have an impact on productivity and can be used in the decision process when considering transitioning environments.
ContributorsThalin, William (Author) / Sullivan, Kenneth (Thesis advisor) / Smithwick, Jake (Committee member) / Stone, Brian (Committee member) / Arizona State University (Publisher)
Created2017
Description
Honeycomb sandwich panels have been used in structural applications for several decades in various industries. While these panels are lightweight and rigid, their design has not evolved much due to constraints imposed by available manufacturing processes and remain primarily two-dimensional extrusions sandwiched between facings. With the growth in Additive Manufacturing, more complex geometries can now be produced, and advanced design techniques can be implemented into end use parts to obtain further reductions in weight, as well as enable greater multi-functionality. The question therefore is: how best to revisit the design of these honeycomb panels to obtain these benefits?
In this work, a Bio-Inspired Design approach was taken to answer this question, primarily since the hexagonal lattice is so commonly found in wasp and bee nests, including the well-known bee’s honeycomb that inspired these panel designs to begin with. Whereas prior honeycomb panel design has primarily focused on the hexagonal shape of the unit cell, in this work we examine the relationship between the various parameters constituting the hexagonal cell itself, specifically the wall thickness and the corner radius, and also examine out-of-plane features that have not been previously translated into panel design. This work reports findings from a study of insect nests across 70 species using 2D and 3D measurements with optical microscopy and X-ray tomography, respectively. Data from these biological nests were used to identify design parameters of interest, which were then translated into design principles. These design principles were implemented in the design of honeycomb panels manufactured with the Selective Laser Sintering process and subjected to experimental testing to study their effects on the mechanical behavior of these panels.
In this work, a Bio-Inspired Design approach was taken to answer this question, primarily since the hexagonal lattice is so commonly found in wasp and bee nests, including the well-known bee’s honeycomb that inspired these panel designs to begin with. Whereas prior honeycomb panel design has primarily focused on the hexagonal shape of the unit cell, in this work we examine the relationship between the various parameters constituting the hexagonal cell itself, specifically the wall thickness and the corner radius, and also examine out-of-plane features that have not been previously translated into panel design. This work reports findings from a study of insect nests across 70 species using 2D and 3D measurements with optical microscopy and X-ray tomography, respectively. Data from these biological nests were used to identify design parameters of interest, which were then translated into design principles. These design principles were implemented in the design of honeycomb panels manufactured with the Selective Laser Sintering process and subjected to experimental testing to study their effects on the mechanical behavior of these panels.
ContributorsGoss, Derek Lee (Author) / Bhate, Dhruv (Thesis advisor) / Lewis, Sharon (Committee member) / Nam, Changho (Committee member) / Arizona State University (Publisher)
Created2020
Description
One of the fundamental aspects of cellular material design is cell shape selection. Of particular interest is how this selection can be made in the context of a realistic three-dimensional structure. Towards this goal, this work studied the stiffness response of periodic and stochastic lattice structures for the loading conditions of bending, torsion and tension/compression using commercially available lattice design optimization software. The goal of this computational study was to examine the feasibility of developing a ranking order based on minimum compliance or maximum stiffness for enabling cell selection. A study of stochastic shapes with different seeds was also performed. Experimental compression testing was also performed to validate a sample space of the simulations. The findings of this study suggest that under certain circumstances, stochastic shapes have the potential to generate the highest stiffness-to-weight ratio in the test environments considered.
ContributorsSharma, Raghav (Author) / Bhate, Dhruv (Thesis advisor) / Oswald, Jay (Committee member) / Kwon, Beomjin (Committee member) / Arizona State University (Publisher)
Created2019
Description
Thermal management is a critical aspect of microelectronics packaging and often centers around preventing central processing units (CPUs) and graphics processing units (GPUs) from overheating. As the need for power going into these processors increases, so too does the need for more effective thermal management strategies. One such strategy is to utilize additive manufacturing to fabricate heat sinks with bio-inspired and cellular structures and is the focus of this thesis. In this study, a process was developed for manufacturing the copper alloy CuNi2SiCr on the 100w Concept Laser Mlab laser powder bed fusion 3D printer to obtain parts that were 94% dense, while dealing with challenges of low absorptivity in copper and its high potential for oxidation. The developed process was then used to manufacture and test heat sinks with traditional pin and fin designs to establish a baseline cooling effect, as determined from tests conducted on a substrate, CPU and heat spreader assembly. Two additional heat sinks were designed, the first of these being bio-inspired and the second incorporating Triply Periodic Minimal Surface (TPMS) cellular structures, with the aim of trying to improve the cooling effect relative to commercial heat sinks. The results showed that the pure copper commercial pin-design heat sink outperformed the additive manufactured (AM) pin-design heat sink under both natural and forced convection conditions due to its approximately tenfold higher thermal conductivity, but that the gap in performance could be bridged using the bio-inspired and Schwarz-P heat sink designs developed in this work and is an encouraging indicator that further improvements could be obtained with improved alloys, heat treatments and even more innovative designs.
ContributorsYaple, Jordan Marie (Author) / Bhate, Dhruv (Thesis advisor) / Azeredo, Bruno (Committee member) / Phelan, Patrick (Committee member) / Arizona State University (Publisher)
Created2021