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dc.contributor.authorDatsiou, Kyriaki Corinna
dc.date.accessioned2017-11-20T10:00:38Z
dc.date.available2017-11-20T10:00:38Z
dc.date.issued2017-11-19
dc.identifier.urihttps://www.repository.cam.ac.uk/handle/1810/269408
dc.description.abstractThe demand for flat glass is high and increasing significantly in the building industry as a direct result of architectural requirements for lightness, transparency and natural light. Current architectural trends require glass in curvilinear forms for smooth free-form façades. Two principal challenges arise from this: to cost-effectively produce the desired curvature and; to ensure its safe performance after exposure to ageing. The recent availability of high strength glass provides an opportunity to address the first challenge by developing cold bent glass. Cold bending involves the straining of relatively thin glass components, at ambient temperatures, and is a low energy and cost effective manner of creating curvilinear forms. However, cold bending is not yet widely established as a reliable method. The aim of this thesis is to develop the understanding of cold bent glass during the bending process and to evaluate its post-ageing performance. This thesis, firstly, investigates the mechanical response of monolithic glass plates during the cold bending process. The stability of cold bent glass is investigated experimentally by bending it in double curved anticlastic shapes. A parametric numerical analysis involves different boundary conditions, geometrical plate characteristics and bending parameters. The principal outcome is that a local instability, now termed cold bending distortion, occurs when certain displacement limits are exceeded and could degrade the optical quality of the glass. An evaluation procedure is also formulated to set limits and aid designers/manufacturers to predict the mechanical response and the optical quality of the glass. Cold bent glass is subjected to permanent bending stresses throughout its service life and therefore, its strength degradation after ageing needs to be quantified. Analytical, experimental and numerical investigations are undertaken in this thesis to identify the most effective method for estimating glass strength (evaluation of destructive tests, required number of specimens, statistical analysis methods and sub-critical crack growth). The limited availability of naturally aged toughened glass and the absence of a reliable ageing standard impede the evaluation of its aged performance. Therefore, a parametric experimental investigation of artificial ageing methods on glass is undertaken in this thesis. A procedure for the evaluation of the strength of aged glass is finally, formulated to allow the selection of artificial ageing parameters that correspond to a target level of erosion. The knowledge on artificial ageing and strength prediction acquired above is finally implemented on different types of glass to determine their strength after ageing and assess their safe use in cold bending / load bearing applications. The investigation showed that fully toughened glass has a superior performance to chemically toughened or annealed glass. Overall, the research presented in this thesis demonstrates that high quality cold bent toughened glass can be created when certain applied displacement limits are respected. These can be used as a safe, cost-effective and energy efficient replacement to the more conventional hot bent glass. However, cold bending / load bearing applications in which the stressed glass surface is exposed to ageing, require glass with a relatively high case depth such as fully toughened or bi-tempered glass.
dc.description.sponsorshipEngineering and Physical Sciences Research Council UK (EPSRC), Eckersley o’Callaghan, Onassis Foundation
dc.formatpdf viewer
dc.language.isoen
dc.rightsNo Creative Commons licence (All rights reserved)
dc.rightsAll Rights Reserveden
dc.rights.urihttps://www.rioxx.net/licenses/all-rights-reserved/en
dc.subjectglass
dc.subjectcold bending
dc.subjectglass plates
dc.subjectinstability
dc.subjectfully toughened glass
dc.subjectchemically toughened glass
dc.subjectoptical quality
dc.subjectartificial ageing
dc.subjectnatural ageing
dc.subjectglass strength
dc.subjectstatistical analysis
dc.subjectsubcritical crack growth
dc.subjectstress corrosion
dc.subjectdestructive testing
dc.subjectfractography
dc.subjectannealed glass
dc.subjectoptical distortions
dc.subjectfinite element analysis
dc.subjectresidual surface stress
dc.subjectoptical quality design guidelines
dc.subjectartificial ageing guidelines
dc.subjectglass strength degradation
dc.subjectWeibull statistics
dc.titleDesign and Performance of Cold Bent Glass
dc.typeThesis
dc.type.qualificationlevelDoctoral
dc.type.qualificationnameDoctor of Philosophy (PhD)
dc.publisher.institutionUniversity of Cambridge
dc.publisher.departmentDepartment of Engineering
dc.date.updated2017-11-19T20:34:33Z
dc.identifier.doi10.17863/CAM.15628
dc.publisher.collegeLucy Cavendish
dc.type.qualificationtitlePhD in Engineering
cam.supervisorOverend, Mauro
rioxxterms.freetoread.startdate2017-11-19


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