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  • 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.
671

HEATING APPARATUS THAT AIDS IN THE PREVENTION OF DELAMINAITON IN BIG AREA ADDITIVE MANUFACTURING APPLICATIONS

Teng F Lee (11160336) 15 October 2021 (has links)
This project was a test of concept for an external heating system for Big Area Additive Manufacturing (BAAM) Fused Deposition Modeling (FDM) 3D printers. To goal of the heating system was to prevent or mitigate delamination and warping in BAAM FDM prints by propelling warm air onto printed layers while not interfering with prior functions of the 3D printer.
672

Konstrukce rámu jízdního kola z uhlíkových vláken / Composite Bicycle Frame Design

Bartoška, Vojtěch January 2021 (has links)
This work aims to the design of a carbon fiber bicycle frame with production technology suitable for piece production. The work summarizes the methods of production of composite frames and important parameters that must be respected when designing the frame. A Gravel frame was chosen for the design. The frame was designed for production using stainless steel printed lugs with glued composite tubes. The proposed solution was strength tested. The work also contains a design of a production jig for the construction of bicycle frames.
673

Rozšíření 3D tiskárny o speciální tiskovou hlavu / Extension of the 3D printers for special print head

Helienek, Matúš January 2017 (has links)
This thesis deals with improvement of 3D-manipulator which is currently used for 3D printing. The improvement involves adding a new printer head which will be able to acquire various colors by mixing up to three materials. Furthermore, device is extended with milling as a finishing process responsible for better surface quality of printed object.
674

Výměníky tepla / Heat exchangers

Kuráňová, Helena January 2019 (has links)
The master thesis deals with the issue of heat recovery and efficiency of exchangers. The experimental part is dedicated to the measurment of efficiency of a plastic model of heat exchanger with atypical construction compared to a standard plate heat exchanger. For production of the heat exchangers 3D printer was used so the thesis uses the possibilities that 3D printing is offering nowadays.
675

Topologická optimalizace závěsu na poddajném podkladu / Topology Optimization of the Hinge on Elastic Foundation

Beruashvili, Vasili January 2020 (has links)
Tato diplomová práce se zabývá modifikací původního tvaru součásti za účelem co nejlepšího splnění provozních podmínek daného zatížení a omezujících podmínek v programech M.S.C. NASTRAN, M.S.C. PATRAN a FUSION 360. Součást je připevněna na ortotropní desce (sendvičovém panelu). Cílem této práce je zjištění efektu elastického podkladu na výsledky optimalizace. Součást bude optimalizována za použití různých cílových funkcí a omezení. Elastický podklad změní tuhost, což může změnit napěťový stav součásti. Únosnost původního a modifikovaného tvaru bude srovnána pomocí programu M.S.C NASTRAN/PATRAN. Po tvarové optimalizaci má být 3D model připravený pro výrobní proces, který bude cenově nejefektivnější.
676

Návrh malé multifunkční modelářské CNC frézky / Design of small multifunctional hobby CNC milling machine

Strnad, Jiří January 2021 (has links)
This diploma thesis deals with the construction proposal of a small multifunctional modeller CNC milling machine that enables milling of aluminium alloys and 3D printing using the FDM method. Based on the research, analyzes and defined entry requirements the construction proposal is created and verified by calculations. The thesis contains a description of all the construction parts including the printhead, the tool tray and the safety cover. The other part of the thesis describes the machine geometry adjustment and specifies the choice of control system. The thesis includes a 3D model and the drawing documentation of selected structural nodes.
677

Tribological and Mechanical Behaviour of 3D Printed Polymeric Bearings

Qazi, Sallar Ali January 2021 (has links)
Plastics contribute 2 GTons to the global carbon footprint, today, several countries have set targets to achieve carbon neutrality. Plastics, being a major contributor to global carbon footprint, would need to be reduced significantly from our daily life to achieve that or a way needs to be devised to recycle them. A big bottleneck in this process is to reduce the consumption of thermosetting plastics or to reduce the emissions associated with plastic and move towards economical and environmentally safe plastics having a longer lifespan and efficient recyclability. Fused filament fabrication (FFF) is the most commonly used 3D printed technology available today. Its applications range from production of prototypes to hollow shafts, and fully functional commercial components. This technology is revolutionary in a sense that it offers advantages such as cheaper raw materials, high degree of customizability, production in smaller batches at lower costs, decrease in material wastage, rapid prototyping, and complex geometry. A number of thermoplastic polymers can be used with FFF technology to produce parts, in addition research is on going to print materials not commonly used for FFF process. Polyoxymethylene (POM) could be a viable option for utilization as FFF basestock for the production of tribologically functional components. POM is an engineering thermoplastic that offers high resistance to wear, low friction, excellent impact resistance, and good chemical resistance. These properties render it suitable for production of gear wheels and low load bearings. It is currently processed using traditional manufacturing methods such as injection and compression moulding, while its printability has received very little attention in the openly available literature. An attempt has been made in this thesis to fill up this research gap by providing insight into POM filament quality, and the thermal, mechanical, and tribological behaviour of POM printed parts. The influence of overfill and layer height on the bulk properties of the printed samples, its play with counterface surface roughness and applied load has also been investigated.
678

A Methodology to Predict the Impact of Additive Manufacturing on the Aerospace Supply Chain

William Bihlman (8741343) 22 April 2020 (has links)
This dissertation provides a novel methodology to assess the impact of additive manufacturing (AM) on the aerospace supply chain. The focus is serialized production of structural parts for the aeroengine. This methodology has three fundamental steps. First, a screening heuristic is used to identify which parts and assemblies would be candidates for AM displacement. Secondly, the production line is characterized and evaluated to understand how these changes in the bill of material might impact plant workflow, and ultimately, part and assembly cost. Finally, the third step employs an integer linear program (ILP) to predict the impact on the supply chain network. The network nodes represent the various companies – and depending upon their tier – each tier has a dedicated function. The output of the ILP is the quantity and connectivity of these nodes between the tiers.<br><br>It was determined that additive manufacturing can be used to displace certain conventional manufacturing parts and assemblies as additive manufacturing’s technology matures sufficiently. Additive manufacturing is particularly powerful if adopted by the artifact’s design authority (usually the original equipment manufacturer – OEM) since it can then print its own parts on demand. Given this sourcing flexibility, these entities can in turn apply pricing pressure on its suppliers. This phenomena increasing has been seen within the industry.
679

FUSION BONDING OF FIBER REINFORCED SEMI-CRYSTALLINE POLYMERS IN EXTRUSION DEPOSITION ADDITIVE MANUFACTURING

Eduardo Barocio (5929505) 16 January 2020 (has links)
<p>Extrusion deposition additive manufacturing (EDAM) has enabled upscaling the dimensions of the objects that can be additively manufactured from the desktop scale to the size of a full vehicle. The EDAM process consists of depositing beads of molten material in a layer-by-layer manner, thereby giving rise to temperature gradients during part manufacturing. To investigate the phenomena involved in EDAM, the Composites Additive Manufacturing Research Instrument (CAMRI) was developed as part of this project. CAMRI provided unparalleled flexibility for conducting controlled experiments with carbon fiber reinforced semi-crystalline polymers and served as a validation platform for the work presented in this dissertation. </p> <p>Since the EDAM process is highly non-isothermal, modeling heat transfer in EDAM is of paramount importance for predicting interlayer bonding and evolution of internal stresses during part manufacturing. Hence, local heat transfer mechanisms were characterized and implemented in a framework for EDAM process simulations. These include local convection conditions, heat losses in material compaction as well as heat of crystallization or melting. Numerical predictions of the temperature evolution during the printing process of a part were in great agreement with experimental measurements by only calibrating the radiation ambient temperature. </p> In the absence of fibers reinforcing the interface between adjacent layers, the bond developed through the polymer is the primary mechanisms governing the interlayer fracture properties in printed parts. Hence, a fusion bonding model was extended to predict the evolution of interlayer fracture properties in EDAM with semi-crystalline polymer composites. The fusion bonding model was characterized and implemented in the framework for EDAM process simulation. Experimental verification of numerical predictions obtained with the fusion bonding model for interlayer fracture properties is provided. Finally, this fusion bonding model bridges the gap between processing conditions and interlayer fracture properties which is extremely valuable for predicting regions with frail interlayer bond within a part.
680

Vers une muséographie numérique : l’impression 3D en tant que dispositif de traduction auprès de publics malvoyants et aveugles

Bérubé, Patricia 04 1900 (has links)
No description available.

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