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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.
61

The specification of a consumer design toolkit to support personalised production via additive manufacturing

Sinclair, Matthew January 2012 (has links)
This thesis stems from the future scenario that as additive manufacturing (AM) technologies become cheaper and more readily available, consumers without formal design training will begin to customise, design and manufacture their own products. Much of this activity is likely to infringe on brands' intellectual property. The research explores the feasibility of a situation in which, rather than attempting to prohibit such activity, manufacturers engage with consumers to facilitate it, thus retaining control (albeit reduced) over their brand's image and the quality of products offered. The research begins with a literature review encompassing AM technologies and their adoption by consumers; mass customisation (MC) and the management of variation in product offering; and traditional models of industrial design (ID), including user-centred design and co-design. It finds that conventional definitions of MC and ID are unable to provide for the possibility of consumer intervention in the shape and non-modular configuration of products. Further research was then conducted in the areas of Open Design (including crowdsourcing, open sourcing and 'hardware hacking') as well as bespoke customisation, which were found to be much more accommodating of the scenario proposed. A new term, 'consumer design', is introduced and defined, together with the hypothesis that in future, the role of the industrial designer may be to design 'unfinished' products. An original classification of consumer involvement in ID is presented. Empirical research, undertaken with consumers using an iterative design software package (Genoform), demonstrated a preference for designing within pre-determined boundaries. Action research was conducted to assess consumer-oriented 3D CAD software, and compare its capabilities with that of MC toolkits. A survey of senior designers and brand managers revealed strategies for implementing and managing a brand's product design language, and a guide was created to show the relative importance of designed features. Using these findings, a prototype toolkit was created to demonstrate how a brand might facilitate consumer interaction with the shape design of a complex consumer electronics product (in this case a mobile phone). The toolkit was tested with both consumers and experienced designers to assess its viability. The research finds that it is possible to create a consumer-design toolkit which enables untrained users to change the form of a product, whilst maintaining brand equity and ensuring the product's functionality and manufacturability.
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62

Design for rapid manufacture : developing an appropriate knowledge transfer tool for industrial designers

Burton, Michael J. January 2005 (has links)
Numerous works have been produced on the topic of Design for Manufacturing (DFM) to better educate the designers of products as to various methods of manufacturing and their specific requirements. It is the common aim of these works to eliminate so called "over the wall" product development in which procedurally ignorant designers pass largely un-producible design concepts to manufacturers, who are then required to make necessary refinements and changes. When applied correctly, DFM results in the efficient and economical production of well-designed products, whose forms have been attuned to the particular requirements of their final method of production at an early stage of development. However, one aspect of using such approaches is that design intent is frequently compromised for the sake of manufacturability and innovative design concepts are often dismissed as being unfeasible. Recent advances in additive manufacturing technologies and their use in the direct manufacture of end-use products from digital data sources has brought about a new method of production that is known as Rapid Manufacturing (RM). Unlike conventional subtractive machining processes, such as milling and turning which generate forms by removing material from a stock billet, RM parts are grown from an empty part bed using the controlled addition of specialised build materials. Additive manufacturing requires no forming tools, is unrestricted by many conventional process considerations and is capable of producing practically any geometry. The freedoms that are associated with this technology facilitate the design and realisation of product concepts that would be unachievable with any other method of production. This promotes an almost boundless design philosophy in which innovative product solutions can be designed to best meet the needs of specification criteria, rather than the production process with which they are to be made. However, unlike other forms of manufacturing, the newness of this technology means that there is no proven aid or tool to assist industrial designers in exploiting the freedoms that it offers. Using information that was collated in the literature review and case study projects, a systematic design approach was proposed and then tested in a series of user trials with groups of industrial design students and practicing industrial design professionals. The results of these trials are discussed, showing a common acknowledgement from both groups that the proposed DFRM tool was of assistance and that it had an influence upon their design work. However, whilst the student group were generally receptive toward tool uptake, the experienced designers showed more of a reluctance to abandon their own "tried and tested" methods in favour of the unknown and unproven approach. It is concluded that this attitude would be fairly representative of wider opinion and that the future uptake of any such tool would be reliant upon sufficient evidence of its successful application. Hence, suggestions are made for future work to continue tool development and for more validation trials to be conducted with its intended user group.
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63

Use of additive manufacturing in interior product development

Linhartová, Iva January 2016 (has links)
Diploma thesis Use of additive manufacturing in interior product development is focused on researching whether there is a use for 3D printing and related technologies from theoretical as well as from practical site of the issue. It focuses on possibilities of layered manufacturing and related technologies, material possibilities and practical application in the field of interior products. Practical part of the thesis consists of material and component testing.
64

3D Printed Heat Exchangers: An Experimental Study

January 2018 (has links)
abstract: As additive manufacturing grows as a cost-effective method of manufacturing, lighter, stronger and more efficient designs emerge. Heat exchangers are one of the most critical thermal devices in the thermal industry. Additive manufacturing brings us a design freedom no other manufacturing technology offers. Advancements in 3D printing lets us reimagine and optimize the performance of the heat exchangers with an incredible design flexibility previously unexplored due to manufacturing constraints. In this research, the additive manufacturing technology and the heat exchanger design are explored to find a unique solution to improve the efficiency of heat exchangers. This includes creating a Triply Periodic Minimal Surface (TPMS) geometry, Schwarz-D in this case, using Mathematica with a flexibility to control the cell size of the models generated. This model is then encased in a closed cubical surface with manifolds for fluid inlets and outlets before 3D printed using the polymer nylon for thermal evaluation. In the extent of this study, the heat exchanger developed is experimentally evaluated. The data obtained are used to derive a relationship between the heat transfer effectiveness and the Number of Transfer Units (NTU).The pressure loss across a fluid channel of the Schwarz D geometry is also studied. The data presented in this study are part of initial experimental evaluation of 3D printed TPMS heat exchangers.Among heat exchangers with similar performance, the Schwarz D geometry is 32% smaller compared to a shell-and-tube heat exchanger. / Dissertation/Thesis / Masters Thesis Mechanical Engineering 2018
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65

Hybrid heritage : an investigation into the viability of 3D-printed Mashrabiya window screens for Bahraini dwellings

Almerbati, Nehal January 2016 (has links)
Current debates on design and manufacturing support the claim that the ‘Third Industrial Revolution’ has already started due to Additive Manufacturing (AM) and 3D Printing. The process of solidifying liquid or powder using a binding agent or a melting laser can save time and transportation costs associated with importing primary material if locally sourced material is available. This research investigates a framework approach, titled SAFE, for discussing the functionality, economic viability, production feasibility, and aesthetic and cultural value lent by 3D printing on an architectural scale through a construction known as a Mashrabiya. This traditional window screen has distinguished aesthetic, cultural yet functional constraints, and there is a manufacturing gap in the market that makes it a viable product option to be 3D printed. The practical element and design process related to reviving this screen are examined, from complex geometry development to cost and fabrication estimations. 3D printing technologies potentially offer solutions to solve issues in construction and assembly times, reduce labour costs, and address the loss of hand craft making skills in a variety of cultures, typically Middle Eastern ones; this was a factor in the abandonment of old Mashrabiya in houses typified with Bahrain as a case. Presently, there is a growing wealth of literature that highlights not only the strength of Mashrabiya as a design concept but also as a possible 3D printed product. Interviews with a total of 42 local Bahraini manufacturers, academics and architects as well as 4 case studies and 2 surveys and 11 focus groups are hybrid mixed methods used to define a new 3D printed Mashrabiya (3DPM) prototype. The future of the 3D Mashrabiya prototype is further supported by economic forecasts, market research, and interviews with global manufacturers and 3D printing designers’ insights into the subject in an accretive design process. The research contributes to an understanding of the implications of technologies that enable mass customisation in the field of 3D-printed architecture in general and in the Bahraini market in particular. The process for developing a prototype screen and in determining its current economic value will prove significant in predicting the future benefits and obstacles of 3D-printed large scale architectural products in the coming five years as advised by industry experts. The main outcomes relate to establishing boundaries determining the validity of using 3D printing and a SAFE framework to produce a parametric Mashrabiya and other similar heritage architectural archetypes. This can be used to enhance the globalism of the design of Middle Eastern dwellings and to revive social identity and cultural traditions through innovative and reasonable yet superior design solutions using a hybrid architectural design language.
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66

Optimising additive manufacturing for fine art sculpture and digital restoration of archaeological artefacts

Zhang, Fangjin January 2014 (has links)
Additive manufacturing (AM) has shown itself to be beneficial in many application areas, including product design and manufacture, medical models and prosthetics, architectural modelling and artistic endeavours. For some of these applications, coupling AM with reverse engineering (RE) enables the utilisation of data from existing 3D shapes. This thesis describes the application of AM and RE within sculpture manufacture, in order to optimise the process chains for sculpture reproduction and relic conservation and restoration. This area poses particular problems since the original artefacts can often be fragile and inaccessible, and the finishing required on the AM replicas is both complex and varied. Several case studies within both literature and practical projects are presented, which cover essential knowledge of producing large scale sculptures from an original models as well as a wide range of artefact shapes and downstream finishing techniques. The combination of digital technologies and traditional art requires interdisciplinary knowledge across engineering and fine art. Also, definitions and requirements (e.g. 'accuracy'), can be applied as both engineering and artistic terms when specifications and trade-offs are being considered. The thesis discusses the feasibility for using these technologies across domains, and explores the potential for developing new market opportunities for AM. It presents and analyses a number of case study projects undertaken by the author with a view to developing cost and time models for various processes used. These models have then been used to develop a series of "process maps", which enable users of AM in this area to decide upon the optimum process route to follow, under various circumstances. The maps were validated and user feedback obtained through the execution of two further sculpture manufacturing projects. The thesis finishes with conclusions about the feasibility of the approach, its constraints, the pros and cons of adopting AM in this area and recommendations for future research.
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67

Bio-Inspired Design of Next Generation Honeycomb Sandwich Panel Cores

January 2020 (has links)
abstract: 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. / Dissertation/Thesis / Masters Thesis Manufacturing Engineering 2020
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68

A Parametric Framework for Modeling and Manufacturing an Ant Neck Joint

Bischof, Ryan January 2020 (has links)
No description available.
69

FABRICATION AND PERFORMANCE EVALUATION OF SANDWICH PANELS PRINTED BY VAT PHOTOPOLYMERIZATION

Nath, Shukantu Dev 01 September 2021 (has links)
Sandwich panels serve many purposes in engineering applications. Additive manufacturing opened the door for easy fabrication of the sandwich panels with different core structures. In this study, additive manufacturing technique, experiments, and numerical analysis are combined to evaluate the mechanical properties of sandwich panels with different cellular core structures. The sandwich panels having honeycomb, re-entrant honeycomb, diamond, square core topologies are printed with the vat photopolymerization technique. Uniaxial compression testing is performed to determine the compressive modulus, strength, and specific strength of these lightweight panels. Elasto-plastic finite element analysis having good similarities with the experimental results provided a preview of the stress distribution of the sandwich panels under applied loading. The imaging of the tested samples showed the fractured regions of the cellular cores. Dynamic mechanical analysis of the panels provided scope to compare the performance of panels and solid materials with the variation of temperature. Sandwich panels with the diamond structure exhibit better compressive properties and specific strength while the re-entrant structure offers high energy absorption capacity. The sandwich structures provided better thermo-mechanical properties than the solid material. The findings of this study offer insights into the mechanical properties of sandwich panels printed with vat photopolymerization technique which can benefit a wide range of engineering applications.
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70

The viability of poly (chlorotrifluoroethylene-co-vinylidene fluoride) as an oxidiser in extrudable pyrotechnic compositions

Cowgill, Andrew William January 2017 (has links)
In a push towards more environmentally friendly pyrotechnics, new greener pyrotechnic compositions need to be developed. A primary goal is to replace components such as lead, barium, and chromium in pyrotechnic compositions. Fused Deposition Modelling (FDM) is a 3D printing/additive manufacturing method whereby a thin filament is passed through a heated nozzle, and extruded onto a substrate in successive layers. This method of manufacturing could be used to produce pyrotechnic time delays based on suitable “green” polymer/fuel mixtures. Fluoropolymers are an attractive oxidising system for pyrotechnic use as fluorine is highly reactive and reacts relatively easily with common metallic fuels such as aluminium and magnesium to release a large amount of energy. Fluoropolymers are already in use as oxidisers and binders, especially in infrared decoy flares. PTFE has found wide use in the pyrotechnics industry, but is not melt-processible. A similar fluoropolymer, poly(chloro-trifluoroethylene) (PCTFE) was considered instead. PCTFE differs from PTFE in that one of the fluorine atoms in the TFE monomer has been replaced by a chlorine atom. The larger chlorine atom interferes with the packing of the polymer chains during polymerisation and, as such, may make it easier to process than PTFE. It was found that pure PCTFE degraded heavily during processing and was therefore precluded from any further study. Melt-processible copolymers containing PCTFE are available from industry. These copolymers contain vinylidene fluoride (VDF) in addition to the CTFE i.e. poly(CTFE-co-VDF). Two grades of copolymer were obtained from 3M: FK-800® resin and Dyneon® 31508 resin. These two polymers contain different ratios of CTFE to VDF. FK-800® resin was successfully extruded and showed minimal signs of degradation. Pyrotechnic films, containing aluminium powder as the fuel, were cast with both polymers using solvent techniques. Differential thermal analysis (DTA) was used to determine the ignition points of the compositions. All of the FK-800®-based compositions ignited at approximately 450 °C whilst all the Dyneon® 31508-based compositions ignited at approximately 400 °C. The energy output of the compositions was determined using bomb calorimetry. The experimental energy outputs of the FK-800®-based compositions correlated well with the predictions from the thermodynamic simulations. The maximum energy output, ~7.0 MJ∙kg1, occurred at a fuel loading between 30 – 35 wt.%. Except for one composition, the Dyneon® 31508-based compositions did not ignite in the bomb calorimeter. FK-800® was successfully extruded into a filament and showed minimal signs of degradation. In order to assess the impact of adding a solid filler on the mechanical properties and extrudability of the polymer, magnesium hydroxide was used as inactive model compound in place of aluminium. A filament of FK-800® and Mg(OH)2 was successfully compounded and produced using a filler loading of 30 wt.%. Compounding of the Dyneon 31508® with the magnesium hydroxide was unsuccessful. Addition of LFC-1® liquid fluoroelastomer improved the processibility of the Dyneon 31508® by lowering the melt viscosity. / Dissertation (MEng)--University of Pretoria, 2017. / Chemical Engineering / MEng / Unrestricted
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