- About
-
The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
provided by the
Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
Search results
Showing 251 to 258 of 258 (0.13 seconds)Spelling suggestions: "subject:"computeraided engineering"" "subject:"computeraided ingineering""
| 251 |
Deep Ocean Vehicle Applications and ModificationsArm, Nichole "Nikki" T 01 December 2023 (has links) (PDF)
This project had two primary goals: (1) to explore opportunities to further a deep-ocean vehicle’s reach using alternative pressure spheres, and (2) to implement an existing deep-ocean vehicle (lander) in active scientific research.
I gained a greater understanding of the limitations and design choices made for existing pressure spheres using Finite Element Analysis (FEA). My simplified FEA model predicted sphere failure for the existing 30% Fiber Glass 70% Nylon injection molded spheres at an external pressure of 3,954psi or 2,690m ocean-depth (only a 7.38% error compared to the tested minimum failure depth), so I determined it a valid model. I also explored alternative designs and materials that could be used for pressure spheres in deep-sea applications. Existing pressure sphere models filled with an incompressible fluid failed at 12,670psi or 8,621m ocean-depth - over three times the depth of the same sphere filled with air. Next, I varied the sphere thickness of existing spheres to determine its impact on depth rating. While the increased thickness did provide an increase in depth rating, there were diminishing returns as the sphere was made thicker. I deemed both of these design options infeasible for our application.
To consider the use of laminated composite spheres, the addition of an equatorial ring was required to manufacture O-ring seals safely and reliably. A simple cylindrical equatorial ring model using a stainless-steel ring had a predicted failure at 3,017psi or 2,053m ocean-depth. While this model predicted failure at 637m shallower than the sphere without the ring, it was the only ring material tested to reach the rated depth for the existing pressure spheres (2km), so I concluded stainless-steel is the best ring material. A spherical stainless-steel equatorial ring design was then analyzed which predicted failure at 3,915psi or 2,664m ocean-depth – only 8.3% less than the original sphere with no ring. Because of its successful performance and near identical results to the original model, I determined a stainless-steel spherical equatorial ring is the best option for laminated composite sphere sealing.
Finally, I analyzed three different kinds of laminated composite pressure spheres: two carbon fiber and one fiber glass. Each laminate was designed to be quasi-isotropic and as close to 0.8” thick as possible to keep it consistent with the original sphere design. The sphere made of 584 Carbon Fiber with a lay-up of: [[-45/45/0/90]6]s was found to predict failure at 10,000psi or 6,804m ocean-depth, more than 2.5 times that of the original sphere. Next, a model made of 282 Carbon Fiber with a lay-up of: [[-45/45/0/90]11]s predicted failure at 9,242psi or 6,289m ocean-depth – more than 2.3 times as deep as the original pressure spheres. Lastly, a sphere of 7781 Fiber Glass with a lay-up of: [[-45/45/0/90]11]s predicted failure at 6,630psi or 4,511m ocean-depth – about two-thirds the depth of the 584 Carbon Fiber composite, but more than 1.6 times the depth of the original sphere. While real-life applications of these materials would include design modifications and manufacturing imperfections which would lower their maximum depth rating, these results are highly encouraging and show that all three materials could be viable options for future production.
Additionally, through partnership with Dr. Crow White and his marine science undergraduate students, I completed numerous deployments for a Before and After Controlled Impact (BACI) study on the area of the proposed windfarm off the coast of Morro Bay, CA. Many modifications were made to the existing lander which enabled it to successfully be implemented in these studies including a new bait containment unit, light color filters, a GPS tracking device, and a large vessel recovery device. A total of 5 pier deployments and 3 boat deployments were conducted by my team over the course of 6-months. Planning for these deployments included accounting for budgeting, weather, permitting, and multi-organizational logistics while working with both NOAA and the Cal Poly marine operations staff.
|
| 252 |
Open Guitar Building ProjectHemphill, Bill 01 January 2022 (has links)
The ETSU Guitar Project’s Open Education Resource (OER) site is a repository of shareable files developed and used in the design & fabrication of electric and acoustic guitars. Begun in 2010, the ETSU Guitar Building Program is affiliated with the NSF-sponsored, national STEM Guitar Project to increase student engagement in the STEM disciplines from K-12 to Higher Ed. Guitar design, prototyping & build activities in the ENTC 3600 Manufacturing Technologies course use a hands-on mix of 2D CADD, 3D modeling, traditional woodworking, CNC routing and laser etching operations in a custom shop-type environment to create unique electric solid body and semi-hollow body electric guitars. Beginning in 2019, the Engineering Technology program faculty began partnering with faculty in ETSU’s groundbreaking Department of Bluegrass, Old Time, and Roots Music Studies program in building acoustic instruments. Designs of common and specialty acoustic instrument building including luthiers’ tooling, molds, templates, jigs and fixtures as well as alternative bracing are available from this repository. / https://dc.etsu.edu/etsu-oer/1009/thumbnail.jpg
|
| 253 |
Hybridization of particle Swarm Optimization with Bat Algorithm for optimal reactive power dispatchAgbugba, Emmanuel Emenike 06 1900 (has links)
This research presents a Hybrid Particle Swarm Optimization with Bat Algorithm (HPSOBA) based
approach to solve Optimal Reactive Power Dispatch (ORPD) problem. The primary objective of
this project is minimization of the active power transmission losses by optimally setting the control
variables within their limits and at the same time making sure that the equality and inequality
constraints are not violated. Particle Swarm Optimization (PSO) and Bat Algorithm (BA)
algorithms which are nature-inspired algorithms have become potential options to solving very
difficult optimization problems like ORPD. Although PSO requires high computational time, it
converges quickly; while BA requires less computational time and has the ability of switching
automatically from exploration to exploitation when the optimality is imminent. This research
integrated the respective advantages of PSO and BA algorithms to form a hybrid tool denoted as
HPSOBA algorithm. HPSOBA combines the fast convergence ability of PSO with the less
computation time ability of BA algorithm to get a better optimal solution by incorporating the BA’s
frequency into the PSO velocity equation in order to control the pace. The HPSOBA, PSO and BA algorithms were implemented using MATLAB programming language and tested on three (3)
benchmark test functions (Griewank, Rastrigin and Schwefel) and on IEEE 30- and 118-bus test
systems to solve for ORPD without DG unit. A modified IEEE 30-bus test system was further used
to validate the proposed hybrid algorithm to solve for optimal placement of DG unit for active
power transmission line loss minimization. By comparison, HPSOBA algorithm results proved to
be superior to those of the PSO and BA methods.
In order to check if there will be a further improvement on the performance of the HPSOBA, the
HPSOBA was further modified by embedding three new modifications to form a modified Hybrid
approach denoted as MHPSOBA. This MHPSOBA was validated using IEEE 30-bus test system to
solve ORPD problem and the results show that the HPSOBA algorithm outperforms the modified
version (MHPSOBA). / Electrical and Mining Engineering / M. Tech. (Electrical Engineering)
|
| 254 |
CAE systém EPLAN Electric P8 - tvorba výkresové dokumentace pro dálkové ovládání motorgenerátoru / CAE system EPLAN Electric P8 and design documentationMěřínský, Jiří January 2010 (has links)
This Graduation Theses dissertate about a creation of a drawing documentation at the professional CAE EPLAN Electric P8 system. One original solution of a remote control and of motor-generator monitoring with a mobile phone, short SMS-aided in this case, was used as an example of the drawing documentation. As has allready been noted in previous Bachelor Thesis, this application can be use not only for a remote control of a motor-generator, but this solution is suitable for other electric devices too, which are out of reach of an attendance for example. In our case a generator with 6kVA power is concerned with rated output voltage 230Vac and rated current 25A. The system of a remote control has the advantage that it is created from standard components (electric instruments, a PLC – programmable automat, a GSM modem, an operating panel and the respective program in the PLC).
|
| 255 |
BBT Side Mold AssyHemphill, Bill 07 June 2022 (has links)
This electronic document file set covers the design and fabrication information of the ETSU Guitar Building Project’s BBT (OM-sized) Side Mold Assy for use with the STEM Guitar Project’s standard acoustic guitar kit. The extended 'as built' data set contains an overview file and companion video, the 'parent' CADD drawing, CADD data for laser etching and cutting a drill &/or layout template, CADD drawings in AutoCAD .DWG and .DXF R12 formats of the centerline tool paths for creating the mold assembly pieces on an AXYZ CNC router, and support documentation for CAM applications including router bit specifications, feeds, speed, multi-pass data, and layer names (formatted for AXYZ's ToolPath CAM software).
|
| 256 |
Vision Beyond Optics: Standardization, Evaluation and Innovation for Fluorescence Microscopy in Life SciencesHuisman, Maximiliaan 01 April 2019 (has links)
Fluorescence microscopy is an essential tool in biomedical sciences that allows specific molecules to be visualized in the complex and crowded environment of cells. The continuous introduction of new imaging techniques makes microscopes more powerful and versatile, but there is more than meets the eye. In addition to develop- ing new methods, we can work towards getting the most out of existing data and technologies. By harnessing unused potential, this work aims to increase the richness, reliability, and power of fluorescence microscopy data in three key ways: through standardization, evaluation and innovation.
A universal standard makes it easier to assess, compare and analyze imaging data – from the level of a single laboratory to the broader life sciences community. We propose a data-standard for fluorescence microscopy that can increase the confidence in experimental results, facilitate the exchange of data, and maximize compatibility with current and future data analysis techniques.
Cutting-edge imaging technologies often rely on sophisticated hardware and multi-layered algorithms for reconstruction and analysis. Consequently, the trustworthiness of new methods can be difficult to assess. To evaluate the reliability and limitations of complex methods, quantitative analyses – such as the one present here for the 3D SPEED method – are paramount.
The limited resolution of optical microscopes prevents direct observation of macro- molecules like DNA and RNA. We present a multi-color, achromatic, cryogenic fluorescence microscope that has the potential to produce multi-color images with sub-nanometer precision. This innovation would move fluorescence imaging beyond the limitations of optics and into the world of molecular resolution.
|
| 257 |
Stratégies numériques avancées pour la simulation de modèles définis sur des géométries de plaques et coques : solutions 3D avec une complexité 2DBognet, Brice 16 April 2013 (has links) (PDF)
La plupart des produits d'ingénierie actuels, que ce soit dans le domaine des transports (naval, aéronautique, automobile, ...), de l'énergie (éolien, ...) ou du génie civil, font massivement appel à des pièces de faible épaisseur de formes variées : les plaques et les coques. Les matériaux métalliques sont toujours très utilisés, bien que l'utilisation des matériaux composites augmente fortement. La conception et le dimensionnement des pièces métalliques et composites nécessite par conséquent des outils de calculs adaptés et performants. L'approche retenue est d'effectuer des simulations mécaniques 3D et d'utiliser la méthode de réduction de modèle PGD (Proper Generalized Decomposition) pour résoudre le problème en variables d'espace séparées. Cette méthode consiste à chercher la solution sous la forme d'une somme finie de produits de fonctions des coordonnées de la surface moyenne et de fonctions de la coordonnée de l'épaisseur. La résolution par la méthode des éléments finis des problèmes 2D (fonction des coordonnées de la surface moyenne) et 1D (fonction de la coordonnée de l'épaisseur) issus de la séparation des variables permet de construire de façon itérative la solution 3D du problème avec une complexité qui reste celle d'un problème 2D. Des variables supplémentaires sont également ajoutées en tant que coordonnées du problème afin d'inclure dans les simulations d'éventuelles incertitudes, variabilités, des paramètres de conception ou des paramètres du procédé d'élaboration. Ces simulations multidimensionnelles fournissent donc des abaques numériques qui peuvent ensuite être utilisées pour la conception et l'optimisation.
|
| 258 |
BBT Acoustic Alternative Top Bracing CADD Data Set-NoRev-2022Jun28Hemphill, Bill 22 July 2022 (has links)
This electronic document file set consists of an overview presentation (PDF-formatted) file and companion video (MP4) and CADD files (DWG & DXF) for laser cutting the ETSU-developed alternate top bracing designs and marking templates for the STEM Guitar Project’s BBT (OM-sized) standard acoustic guitar kit. The three (3) alternative BBT top bracing designs in this release are (a) a one-piece base for the standard kit's (Martin-style) bracing, (b) 277 Ladder-style bracing, and (c) an X-braced fan-style bracing similar to traditional European or so-called 'classical' acoustic guitars.
The CADD data set for each of the three (3) top bracing designs includes (a) a nominal 24" x 18" x 3mm (0.118") Baltic birch plywood laser layout of (1) the one-piece base with slots, (2) pre-radiused and pre-scalloped vertical braces with tabs to ensure proper orientation and alignment, and (3) various gages and jigs and (b) a nominal 15" x 20" marking template.
The 'provided as is" CADD data is formatted for use on a Universal Laser Systems (ULS) laser cutter digital (CNC) device. Each CADD drawing is also provided in two (2) formats: Autodesk AutoCAD 2007 .DWG and .DXF R12. Users should modify and adapt the CADD data as required to fit their equipment. This CADD data set is released and distributed under a Creative Commons license; users are also encouraged to make changes o the data and share (with attribution) their designs with the worldwide acoustic guitar building community.
|
Page generated in 0.1393 seconds