1,395 research outputs found
Finite-Element Numerical Simulation of the Bending Performance of Post-Tensioned Structural Glass Beams with Adhesively Bonded CFRP Tendons
No full textIn this study, a Finite-Element (FE) numerical investigation is carried out on laminated glass beams with Carbon Fibre Reinforced Polymer (CFRP) adhesively bonded post-tensioning tendons. Taking advantage of past four-point bending experimental test results available in literature, a refined full 3D FE numerical model is calibrated and validated. A key role is given to a multitude of aspects, including the implementation of damage models for materials as well as the appropriate mechanical interaction between the beam components, in order to properly reproduce the expected effects of post-tensioning as well as the overall bending behavior for the examined structural typology
Reinforcing glass with glass: Application of transport reinforcement in structural glass beams
No full textDue to the increasing demand of transparency in buildings, it is no longer unusual to apply transparent elements into the bearing structure. Glass is a strong but very brittle material, which means safety is rather problematic should it break. Safety is an issue that has to be improved before glass can be considered suitable for structural elements. Earlier studies have shown that reinforcing glass beams will provide reasonable residual load-bearing capacity, which could provide this safety. Glass fibre is suitable as reinforcement material when the transparency is regarded as important. In February 2009 at the Faculty of Architecture at Delft University of Technology, P.C. Louter designed and tested a laminated glass beam with embedded glass fibre rods. The bonding interlayer consisted of SentryGlas foil, developed by DuPont and often applied for lamination in hurricane-resistant windows. The results were promising and the concept showed high potential for further research. The study of this thesis project is focussed on improving the concept of embedding reinforcement in laminated glass beams.Design and ConstructionCivil Engineering and Geoscience
Thermo-mechanical Numerical Modelling of Structural Glass under Fire - Preliminary Considerations and Comparisons
No full textIn this paper, careful consideration is paid for structural glass elements under fire loading. In particular, a thermo-mechanical Finite Element (FE) numerical investigation is carried out in ABAQUS on small-scale structural glass elements exposed to fire. Taking advantage of past literature efforts, major thermal effects on the material properties are taken into account in the form of key input parameters for numerical simulations. Further validation of the so calibrated FE models is then carried out towards past small-scale experimental fire tests on monolithic glass panels. A sensitivity FE study is hence proposed, giving evidence of major influencing parameters on the thermo-mechanical performance of the same structural glass elements, including variations in the fire exposure, thermal-to-mechanical loading ratio, geometrical and mechanical features of the specimens.OLD Structural Desig
Editorial Challenging Glass Conference 8
No full textWe gradually emerge from two difficult years of the covid-19 pandemic raging through the world in waves of constantly changing intensities. The associated uncertainties really put the ‘challenging’ into Challenging Glass this time. Still, some of our peers are not able to join us in Ghent, and they will be sorely missed. Nevertheless, we are happy to be able to return this year to the ‘real thing’: a live event which allows the international glass community to finally meet again in person. An excellent opportunity, especially within the UN-declared International Year of Glass 2022. We look forward to reconnect with international colleagues and old friends, but we also want to extend a particularly warm welcome to new and young peers who perhaps have not yet had many opportunities to build their professional network.Applied Mechanic
Exploratory Study on the Load-Bearing Behaviour of Laminated Glass Beams Exposed to Fire
No full textAll-glass structures have become increasingly popular with architects and builders in recent years. Glass surfaces are becoming larger and more impressive, while connections are being decreased to obtain maximum transparency. The supporting structure of glass facades, glass roofs or walk-on glazing is mostly made of metal. One of the reasons for this are the fire protection requirements. To increase the overall transparency load-bearing glass structures have recently been given more attention. However, their use is currently still limited due to the concerns about glass performance in case of fire. Within a research study at TU Dresden load-bearing tests in a furnace were carried out to examine the load-bearing behaviour of glass beams exposed to fire. Different glass types and interlayer materials were tested with varying loads. This study provides a closer look at fire performance of glass beams and proposes further examinations to increase the load-bearing capacity in case of fire.Applied Mechanic
Flexible Transparency: a Study on Adaptive Thin Glass Façade Panels
No full textChemically strengthened thin glass (t < 2 mm) is a material that is stronger and due to its small thickness, more flexible than conventional window glass. As such, thin glass offers the possibility for lightweight and flexible glass façades that could change shape depending on external conditions. This paper explores this concept and presents an MSc study on the use of this material in adaptive façade panels. The behavior of thin glass in this context depends on different factors. The glass thickness and strength define its bending limits, while the desired geometry and movement affect its overall stiffness and visual outcome. In order to integrate these factors, different configurations of panels were analyzed in numerical models. These analyses showed the importance of understanding the desired movement and geometry in order to correctly define the supports and degrees of freedom of the panel, avoiding stress concentration (particularly on the edges) and allowing for an unobstructed movement of the panel. The development of these analyses resulted in the conception of a design example of an adaptive façade panel, taking into consideration the design requirements developed in the research. Finally, as a proof of concept, a mock-up was built simulating the behavior of the design example developed in this research. Although there is still the need for research to be developed so that thin glass can become a building material, this research showed that this is possible and that interesting results, regarding visual effect, ventilation and dead load reduction (in larger scale, an environmental impact reduction is also possible) can be achieved. Besides that, using thin glass in adaptive panels challenges the concept of glass as a static material, opening new possibilities for its use.OLD Structural DesignBuilding Product Innovatio
Building and Testing Lenticular Truss Bridge with Glass-Bundle Diagonals and Cast Glass Connections
No full textOn the campus of Delft University the Glass and Transparency Research Group is preparing to build a pedestrian bridge as a low arch consisting of dry-stacked glass blocks. As temporary support for the arch, a lens-shaped truss has been constructed and placed on location. This truss has been fitted with as many glass components as was structurally feasible. The diagonals in the truss are glass bundle struts and the nodes of the truss are cast glass components. The lenticular truss will serve as a temporary bridge during the time the team needs to prepare for construction of the eventual Glass Arch Bridge. Due to the experimental nature of the truss, with its unusual and novel applications of structural glass, a number of demonstrative proof loadings were performed to ease concerns about the safety of the structure. The glass bundles have been proof-loaded to twice their maximum expected load just prior to their installation in the structure. The whole system has then been proof-loaded for several critical load combinations (static and dynamic) just after installation. During the proof-loading the strains in the glass diagonals have been measured. These lie easily within the acceptable limits. In the paper the structural design of the bridge, in particular the glass node connector and the glass bundle diagonals will be explained. Then the proof-loading of the bridge will be described. Then the results of the proof-loading are presented and discussed.OLD Structural DesignApplied Mechanic
Edge-laminated Transparent Structural Silicone Adhesive (TSSA) Steel-to-Glass Connections
No full textThe connections between glass components are very critical aspects of structural glass design. Laminated steel-to-glass connections have recently been developed that combine high strength and transparency. This work focuses on the Transparent Structural Silicone Adhesive (TSSA), produced by Dow Corning. TSSA is typically used for the realization of circular point connections on the glass surface. An alternative approach of using TSSA is considered in this study, by laminating stainless steel connectors on the edge of the glass. These connections are experimentally and numerically investigated. The edge bonded specimens are tested in shear and the stress distribution of the adhesive is analyzed by means of a three-dimensional finite element model. The distribution of stresses in the adhesive is non-linear showing significant stress peaks towards the free edges of the adhesive. A parametric study is conducted to relate the magnitude of the shear stress peaks and bending stresses with the eccentricity of the applied load. The occurrence of failure at lower engineering stresses than the ones recorded for circular point connections is explained using the theory of bending-shear interaction laws. Based on these failure criteria, shear stress peaks that occur due to the eccentricity of the applied load have an important influence on the global resistance of the connection.OLD Structural Desig
Fragile yet Ductile: Structural Aspects of Reinforced Glass Beams
No full textThis dissertation investigates the structural aspects of reinforced glass beams. The concept of these beams, which are intended for building applications, is to provide redundancy even if the glass is broken. This redundancy is obtained through a small reinforcement section that is bonded at the tensile edge of the glass beam. Upon glass failure the reinforcement section bridges the crack and carries the tensile forces over the crack, thereby creating a post-breakage load-carrying mechanism. Various parameters that may influence the structural performance of the reinforced glass beams are experimentally investigated in this dissertation, namely: bond system, temperature, thermal cycling, humidity, load duration, reinforcement material, reinforcement percentage and beam size. This is done by means of pull-out tests, to investigate the pull-out strength of the reinforcement, and by means of bending tests, to investigate the structural response of the reinforced glass beams. Furthermore, analytical and numerical investigations are performed into the modelling of the structural response of reinforced glass beams. The analytical model has been developed in this research in analogy with reinforced concrete. The numerical model makes use of a novel sequentially linear analyses (SLA) scheme and saw-tooth reduction diagrams to simulate cracking of the glass and yielding of the reinforcement and to describe the overall structural response of the beams.Building TechnologyArchitectur
The Chronology of Historical Glass Constructions
No full textGlass surfaces are characteristic elements of façades and make a significant contribution to the authenticity of architectural monuments. Glass as a material is considered an important testimony of its time. Depending on the manufacturing process, it differs both in surface and material composition. The period of high modernism (ca. 1880-1970) overlapped with the technical developments of the industrial revolution, which led from manual production to industrial production. The further development of manufacturing processes as well as the dimensions and qualities of the glass thus shaped the development of glass constructions, which had to be made increasingly slimmer over time in order to guarantee a high degree of transparency. Today, historical windows are often replaced by new glazing made of float glass, which can cause the authentic character of buildings to be lost. A team working on the research project at the Technical University of Dresden and the University of Bamberg has therefore set itself the goal of examining in detail the glass and its construction in the period from around 1880 to around 1970. The aim is to define the living character of industrially manufactured glass from the time before the introduction of float glass as an authentic and style-defining feature of the period. The present work focuses on the chronological presentation of the development of glass designs. Furthermore, the development and use of refined flat glass is analysed and presented. This includes wired glass, laminated glass, thermally toughened glass, insulating glass and curved glass. The significance of historical glass constructions for engineers and planners can be derived from the results and the evaluation.Applied Mechanic
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