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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.
361

Monitorování procesu FDM tisku / Monitoring of FDM printing process

Rafaja, Hynek January 2019 (has links)
The target of this work is the development of a monitoring system for 3D printing by the Fused Deposition Modeling method, which will be able to identify printing error conditions. During the solving process the needed error conditions were identified. Then, an algorithm was programmed to identify the error condition using the criterion. The resulting Monitoring Hardware was implemented in the printer and experimentally verified. A system has been developed that can identify error conditions with an accuracy of 94.7%. The main benefit of this work is the automatic identification of error conditions that stop printing if necessary. This leads to a reduction in scrap and cost savings. In the future, the software could automatically adjust the print parameters when identifying an error condition. This would prevent or completely eliminate the error condition without user intervention.
362

Píst zážehového motoru pro 3-D tisk / Piston of a spark-ignition engine for 3-D printing

Zelko, Lukáš January 2019 (has links)
The goal of the thesis was to design a piston manufactured by conventional method and subsequently adjusted one for additive manufacturing. Beside the designs, thermo-structural model was created for both pistons, considering maximal loading of the engine. Analysis evaluation showed the possibility of further application of the new technology in comparison to current one, within automotive industry.
363

Topologické optimalizace v technické praxi / Topological optimization in technical practice

Mazoch, Jan January 2019 (has links)
Master’s thesis deals with an issue of 3D printing and of using a topological optimization for editing a shape of a 3D printed product. First part of this thesis provides a general description of a subtractive manufacturing technology, specifically its use in CNC milling machines, and of an additive manufacturing technology which is used in 3D printing. Second part of this thesis describes the topological optimization per se and specific methods which are used in the topological optimization. In the third and the fourth part of this thesis, topological optimization modules of software Ansys and SolidWorks are described. In the fifth part of this thesis, the topological optimization capabilities for 3D printed product on a specific embodiments of a design lightning and a cross-beam are demonstrated.
364

Optimalizace 3D tisku a post-processingu pokročilé keramiky na bázi kalcium fosfátu / Optimization of 3D printing and post-processing of advanced ceramics based on calcium phosphate

Valenová, Ludmila January 2021 (has links)
The diploma thesis is related to the preparation of hydroxyapatite complex structures by additive manufacturing known as Lithography based ceramics manufacturing – LCM. A photosensitive suspension containing hydroxyapatite particles was used for 3D printing of ceramic complex structures. The influence of printing parameters on the resulting macrostructure, microstructure, density, and dimensional accuracy was evaluated. The aim was to obtain ceramic components without delamination of the layers and optimise following post-processing steps (cleaning and thermal treatment). It was found that the exposure time has a significant effect on the dimensional accuracy of printed parts. During observation microstructure of printed parts, a microporosity at the interface of printed layers, which can cause delamination of several layers was identified. High-temperature dilatometry showed different temperature of beginning densification process in the longitudinal and perpendicular directions to the layers. That could be an initiation mechanism for delamination of the layers. X-ray diffraction analysis determined a single-phase composition of powder in photosensitive suspension and sintered parts. A commercial product LithaSol 20 was suggested as a suitable cleaning agent and efficiency of the ultrasound field for cleaning was demonstrated. Based on the thermogravimetric analysis an optimized cycle of heat treatment was designed. The optimisation led to time saving (49 hours), while maintaining density, dimensional accuracy and macrostructure of the 3D printed structures.
365

3D tisk kovů robotem / 3D metal printing by robot

Tvrdoň, Radek January 2021 (has links)
The diploma thesis presents an overview of additive production technologies and a summary of technologies used for 3D metal printing using a robot. All of them are generally described and at the same time assigned to their specific commercial use, or the academic research that deals with them. The work examines the suitability of the material EN ISO 14341-A: G 3Si1 for 3D printing, for which a modification of the Col Metal Transfer technology, Cycle Step is used. The experimental printout of the sample is evaluated on the basis of surface and mechanical tests. Capillary test, examination of microstructure a macrostructure, tensile test and microhardness test. All of them were satisfactory and the suitability of the welding wire for 3D printing was confirmed by the given technology.
366

Design klimatizační jednotky pro aditivní robotickou výrobu / Design of the Air conditioning unit for additive robotic fabrication

Mandáková, Adéla January 2021 (has links)
The design of air conditioning unit is based on combination of the product itself and related architecture. The large-scale 3D printing is becoming more and more popular, that is why this thesis chose additive manufacturing robotic technology for designing the air conditioner. According to analysis the air distribution through perforations is the most convenient one for an indoor unit. An outdoor unit tends to be hidden because of inhomogeneity with the building. To obtain more variant studies for the design a generative process was applied. This method was applied also later on, because additive manufacturing is able to easily change dimension parameters and thus fulfil individual customer requests. Other advantages of robotic printing are the lattice structures that enable perforation manufacturing without waste and the possibility of using generative design methods.
367

Form and Functionality of Additively Manufactured Parts with Internal Structure

Ahsan, AMM Nazmul January 2019 (has links)
The tool-less additive manufacturing (AM) or 3D printing processes (3DP) use incremental consolidation of feed-stock materials to construct part. The layer by layer AM processes can achieve spatial material distribution and desired microstructure pattern with high resolution. This unique characteristics of AM can bring custom-made form and tailored functionality within the same object. However, incorporating form and functionality has their own challenge in both design and manufacturing domain. This research focuses on designing manufacturable topology by marrying form and functionality in additively manufactured part using infill structure. To realize the goal, this thesis presents a systematic design framework that focuses on reducing the gap between design and manufacturing of complex architecture. The objective is to develop a design methodology of lattice infill and thin shell structure suitable for additive manufacturing processes. Particularly, custom algorithmic approaches have been developed to adapt the existing porous structural patterns for both interior and exterior of objects considering application specific functionality requirements. The object segmentation and shell perforation methodology proposed in this work ensures manufacturability of large scale thin shell or hollowed objects and incorporates tailored part functionality. Furthermore, a computational design framework developed for tissue scaffold structures incorporates the actual structural heterogeneity of natural bones obtained from their medical images to facilitate the tissue regeneration process. The manufacturability is considered in the design process and the performances are measured after their fabrication. Thus, the present thesis demonstrates how the form of porous structures can be adapted to mingle with functionality requirements of the application as well as fabrication constraints. Also, this work bridges the design framework (virtual) and the manufacturing platform (realization) through intelligent data management which facilitates smooth transition of information between the two ends. / National Science Foundation #OIA-1355466 / National Science Foundation-DMR- MRI #1625704 / National Institute of Health - COBRE: CDTSPC; Grant # P20GM109024 / US-DOT # 693JK31850009CAAP / Dept. of Commerce Research-ND, Award # 17-08-G-191 / CSMS, NDEPSCoR / NDSU Grand Challenge and Development Foundation
368

3D-Printed Surrogate Lower Limb for Testing Ankle-Foot Orthoses

Thibodeau, Alexis 29 September 2021 (has links)
Traditionally, the mechanical testing of ankle-foot orthoses (AFOs) has been performed with simple limb surrogates, typically with a single axis ankle joint and rigid foot and shank components. Since many current AFO designs allow 3D motion, a surrogate lower limb (SLL) that provides anatomically similar motion in all planes is needed to enable realistic load testing and cyclic testing in a controlled manner. The aim of this thesis was to design, fabricate and test a novel SLL that provides anatomically realistic 3D foot motion, based on a consensus of the passive lower limb range of motion (RoM) found in the literature. The SLL design was inspired by the Rizzoli model, sectioning the lower limb into five segments (shank, hindfoot, midfoot, forefoot, toes). Ball and socket joints were used for the shank-hindfoot, hindfoot-midfoot, and midfoot-forefoot. Forefoot-toes used a hinge-type joint. 3D printed flexible thermoplastic polyurethane (TPU) snap-fit connectors connected the 3D printed nylon foot blocks. A threaded ball stud connected the shank shaft and hindfoot. This shank shaft was surrounded by a 3D printed polylactic acid (PLA) shank cover. The foot was cast in silicone rubber to emulate soft tissue, with a PLA custom mould based on a Össur prosthetic foot cover model. The SLL was successfully designed for easy fabrication using readily available techniques, materials, and components. Only the metal shaft required additional machining. 3D printed components used an affordable 3D printer (Artillery Sidewinder X1), and readily available nylon, PLA, and TPU. Using motion capture testing, SLL foot rotation angles were found to be within standard deviation of mean foot passive rotation angle ranges found in the literature, showing that most joints were within 5° of target maximum rotation angles. With load testing, the SLL was shown to survive static loads representing 1.5 times body weight for a 100 kg individuals and cyclic loads representing normal gait loading for 500,000 cycles.
369

Geometrická přesnost výroby kovových dílů aditivní technologií Selective Laser Melting / Geometric Accuracy of Additively Manufactured Test Parts

Ilčík, Jindřich January 2013 (has links)
The presented diploma thesis deals with the control of the geometric accuracy of the parts produced by additive manufacturing technology selective laser melting. The paper first analyzed the work of the other authors dealing with this issue. Based on obtained informations from this analysis were developed benchmark test parts for quality control of production on a commercial machine SLM 280 HL supplied by SLM Solutions GmbH. The work was carried out several tests to determine the appropriate parameters of construction parts. These tests, their results and conclusions are fully described in this papper.
370

Zpracování slitiny 2618 pomocí technologie selective laser melting / Processing of alloy 2618 using selective laser melting technology

Dokoupil, Filip January 2015 (has links)
This diploma thesis deals with finding and verification of appropriate technological parameters of SLM technology for the processing of aluminum alloy 2618. In the theoretical part, an introduction to additive manufacturing of aluminum alloys and general description of processes occurring during SLM production is given. Based on general knowledge were designed different types of testing samples produced by sintering the metallurgical powder using 400 W ytterbium fiber laser, which so far in the literature for aluminum alloy 2618 were not described. As the result, the technological parameters dependence on relative density and the detailed overview of the 2618 alloy processing by SLM technology is determined.

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