Free-form façades with bent glass are becoming increasingly popular. As bending glass provides it with a better resistance to out-of-plane loads, it can result in thinner glass. A promising new technique is to cold bend thin glass plates with a stiff structural edge into a hyperbolic paraboloid (hypar), and to subsequently lock the corners to create a self-contained, self-stressed system. In this study, the bending process of specially-fabricated double glazing units (‘panels’) is investigated with a focus on a local instability phenomenon. The hypothesis that this instability is affected by edge stiffness of the plate, is tested by using 30x30 mm GFRP profiles as spacers along the perimeter of the glass. These were bonded to the glass using Dow 993 silicone adhesive. Four 1.5x1.5 m panels were produced in total, three with 4mm fully toughened (FT) glass, and one with 1.1 mm chemically toughened (CT) glass. The panels were cold bent in a series of laboratory experiments. A numerical model was developed to provide further insight on the mechanical response and to predict the outcome of the experiments. With the sizes of panels used it was not possible to form a hypar. Due to the small thickness of the glass, one the diagonals would always straighten when cold-bent. The 4 mm FT panels failed when the bottom plate fractured at a corner displacement of around 150 mm and a total load of 2.6 kN. The bottom plate of the CT 1.1 mm was also the first to fracture, at a corner displacement of 120 mm and a total load of 1.4 kN. The top and bottom plates came into contact in the centre of the plate when the corner displacement was around 50 mm for the FT 4 mm panels, and around 30 mm for the CT 1.1 mm panel. The numerical model predicted this contact and the overall behaviour of the panel up to a corner displacement of 60 mm. It was concluded that the glass was too thin to create a hypar with this panel size. The experimental data generated along with the numerical model are useful for future research and developments.
{"title":"Investigations on the Cold Bending Behaviour of a Double Glazing Unit with a Rigid Edge-Spacer Frame","authors":"T. V. van Driel, C. Noteboom, M. Overend","doi":"10.47982/cgc.8.422","DOIUrl":"https://doi.org/10.47982/cgc.8.422","url":null,"abstract":"Free-form façades with bent glass are becoming increasingly popular. As bending glass provides it with a better resistance to out-of-plane loads, it can result in thinner glass. A promising new technique is to cold bend thin glass plates with a stiff structural edge into a hyperbolic paraboloid (hypar), and to subsequently lock the corners to create a self-contained, self-stressed system. In this study, the bending process of specially-fabricated double glazing units (‘panels’) is investigated with a focus on a local instability phenomenon. The hypothesis that this instability is affected by edge stiffness of the plate, is tested by using 30x30 mm GFRP profiles as spacers along the perimeter of the glass. These were bonded to the glass using Dow 993 silicone adhesive. Four 1.5x1.5 m panels were produced in total, three with 4mm fully toughened (FT) glass, and one with 1.1 mm chemically toughened (CT) glass. The panels were cold bent in a series of laboratory experiments. A numerical model was developed to provide further insight on the mechanical response and to predict the outcome of the experiments. With the sizes of panels used it was not possible to form a hypar. Due to the small thickness of the glass, one the diagonals would always straighten when cold-bent. The 4 mm FT panels failed when the bottom plate fractured at a corner displacement of around 150 mm and a total load of 2.6 kN. The bottom plate of the CT 1.1 mm was also the first to fracture, at a corner displacement of 120 mm and a total load of 1.4 kN. The top and bottom plates came into contact in the centre of the plate when the corner displacement was around 50 mm for the FT 4 mm panels, and around 30 mm for the CT 1.1 mm panel. The numerical model predicted this contact and the overall behaviour of the panel up to a corner displacement of 60 mm. It was concluded that the glass was too thin to create a hypar with this panel size. The experimental data generated along with the numerical model are useful for future research and developments. ","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131955090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
W. Stevels, T. Fildhuth, T. Wüest, M. Haller, R. Schieber
Minimizing metallic primary structures in directly glazed grid shells is key to increasing transparency. Complete renunciation to a substructure results in the glass itself bearing the loads, with thin glass shells, for example, that support loads mainly via membrane forces. A 4.20 m tall, double-curved, frame-less modular glass shell with stainless steel fittings laminated into the thin interstice of two-ply laminated safety glass has been developed and built as a demonstrator to validate the concept. The fittings used to structurally join the glass modules transfer all translation loads and provide a certain rotational stiffness. They are geometrically designed to reduce stress peaks inside the laminate and feature a laminated contact surface at the edge of the glass. For lamination, an interlayer stack was applied comprising exterior layers of structural PVB to bond the fitting with the glass and translucent PVB as interior core layer for aesthetic reasons. The design of this structure initially relied on generic values for designing and finite element modelling of the fitting-interlayer bond, particularly in tensile “pull-out” mode. The present paper undertakes a review of basic interlayer stack data with regards to viscoelastic properties and adhesion, and the engineering hypotheses using recent preliminary fitting test results for various loading schemes (bending, shear, tensile).
{"title":"Design Base for a Frameless Glass Structure Using Structural PVB Interlayers and Stainless-Steel Fittings","authors":"W. Stevels, T. Fildhuth, T. Wüest, M. Haller, R. Schieber","doi":"10.47982/cgc.8.369","DOIUrl":"https://doi.org/10.47982/cgc.8.369","url":null,"abstract":"Minimizing metallic primary structures in directly glazed grid shells is key to increasing transparency. Complete renunciation to a substructure results in the glass itself bearing the loads, with thin glass shells, for example, that support loads mainly via membrane forces. A 4.20 m tall, double-curved, frame-less modular glass shell with stainless steel fittings laminated into the thin interstice of two-ply laminated safety glass has been developed and built as a demonstrator to validate the concept. The fittings used to structurally join the glass modules transfer all translation loads and provide a certain rotational stiffness. They are geometrically designed to reduce stress peaks inside the laminate and feature a laminated contact surface at the edge of the glass. For lamination, an interlayer stack was applied comprising exterior layers of structural PVB to bond the fitting with the glass and translucent PVB as interior core layer for aesthetic reasons. The design of this structure initially relied on generic values for designing and finite element modelling of the fitting-interlayer bond, particularly in tensile “pull-out” mode. The present paper undertakes a review of basic interlayer stack data with regards to viscoelastic properties and adhesion, and the engineering hypotheses using recent preliminary fitting test results for various loading schemes (bending, shear, tensile).","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127288078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Luca Guidi, Giovanni Inghirami, Gerardo Masiello, Daniele Antonucci, Pasquale Lucia
Façades are one of the main elements that affect indoor environmental quality (IEQ) in buildings and building performance. Given the increasing development of sensor technology, the collection of building monitoring data is useful to understand whether the building and in particular the façade system performs as designed. The increasing use of Technical Building Management (TBM) as well as Building Automatic and Control System (BACs) has been demonstrated to be a promising method to decrease the energy consumption and increase the indoor comfort in new and existing buildings. This project aims to develop a tool showing and processing the monitoring data in a BIM environment using an IFC model. The application has been developed thinking about a BIM approach in the building management. Nowadays IFC models are the most used exchange file format in a BIM process. An IFC file can be loaded into a common data environment (CDE) reachable from stakeholders, sharing information and management strategies. The developed tool is a stand-alone application written in C# which is called MICA (Monitoring Internal Comfort Application). MICA can properly display the monitoring data of building sensors, sharing information between different building actors using the IFC format. It is a platform to visualize, manage and identify the IEQ aspects of building based on real monitored data.
{"title":"MICA (Monitoring Internal Comfort Application):","authors":"Luca Guidi, Giovanni Inghirami, Gerardo Masiello, Daniele Antonucci, Pasquale Lucia","doi":"10.47982/cgc.8.399","DOIUrl":"https://doi.org/10.47982/cgc.8.399","url":null,"abstract":"Façades are one of the main elements that affect indoor environmental quality (IEQ) in buildings and building performance. Given the increasing development of sensor technology, the collection of building monitoring data is useful to understand whether the building and in particular the façade system performs as designed. The increasing use of Technical Building Management (TBM) as well as Building Automatic and Control System (BACs) has been demonstrated to be a promising method to decrease the energy consumption and increase the indoor comfort in new and existing buildings. This project aims to develop a tool showing and processing the monitoring data in a BIM environment using an IFC model. The application has been developed thinking about a BIM approach in the building management. Nowadays IFC models are the most used exchange file format in a BIM process. An IFC file can be loaded into a common data environment (CDE) reachable from stakeholders, sharing information and management strategies. The developed tool is a stand-alone application written in C# which is called MICA (Monitoring Internal Comfort Application). MICA can properly display the monitoring data of building sensors, sharing information between different building actors using the IFC format. It is a platform to visualize, manage and identify the IEQ aspects of building based on real monitored data.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134410020","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The structural performance of laminated glass is strongly dependent on the shear coupling offered by the interlayer between the bounding layered and monolithic limits of the glass plies. The most common simplified design approach consists of defining the effective thickness, i.e., the thickness of a monolithic section with equivalent flexural section properties. The Enhanced Effective Thickness (EET) method has been verified to estimate deflection in laminated glass for a range of load and boundary conditions for two-, three-, and multi-ply beams; however, for some static schemes, the EET method is less accurate for predicting stress. The recently proposed Conjugate Beam Effective Thickness (CBET) method, initially developed for cantilevered laminated glass balustrade applications, accounts for the relative displacement of glass plies across the interlayer for a range of loads and statically determinate boundary conditions. In this paper, the CBET method is extended to the evaluation of two-ply simply supported beams under concentrated, uniformly, and tapered distributed out-of-plane loads. Predicted deflection- and stress-effective thickness obtained from effective thickness methods is compared with finite element model results in illustrative examples, demonstrating improved accuracy. Closed-form formulas are summarized in tables to facilitate the practical application of the CBET method in the design practice.
{"title":"The Conjugate Beam Effective Thickness Method","authors":"L. Galuppi, Adam J. Nizich, Andrea La Greca","doi":"10.47982/cgc.8.434","DOIUrl":"https://doi.org/10.47982/cgc.8.434","url":null,"abstract":"The structural performance of laminated glass is strongly dependent on the shear coupling offered by the interlayer between the bounding layered and monolithic limits of the glass plies. The most common simplified design approach consists of defining the effective thickness, i.e., the thickness of a monolithic section with equivalent flexural section properties. The Enhanced Effective Thickness (EET) method has been verified to estimate deflection in laminated glass for a range of load and boundary conditions for two-, three-, and multi-ply beams; however, for some static schemes, the EET method is less accurate for predicting stress. The recently proposed Conjugate Beam Effective Thickness (CBET) method, initially developed for cantilevered laminated glass balustrade applications, accounts for the relative displacement of glass plies across the interlayer for a range of loads and statically determinate boundary conditions. In this paper, the CBET method is extended to the evaluation of two-ply simply supported beams under concentrated, uniformly, and tapered distributed out-of-plane loads. Predicted deflection- and stress-effective thickness obtained from effective thickness methods is compared with finite element model results in illustrative examples, demonstrating improved accuracy. Closed-form formulas are summarized in tables to facilitate the practical application of the CBET method in the design practice.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122065912","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The mechanical performance of pedestrian structures attracts the attention of several studies, especially with respect to unfavourable operational conditions or possible damage scenarios. In terms of vibrations, for example, specific customer comfort levels must be satisfied, depending on the class of use, the structural typology, the involved materials, in addition to basic safety requirements. A special consideration should be given to in-service systems that are possibly affected by degradation or even damage, and thus potentially unsafe for pedestrians. In this regard, the availability of standardized non-destructive protocols for a reliable and rapid structural safety assessment may result in efficient support for diagnostic analyses. In this paper, 3 different laminated glass (LG) modular units belonging to 2 different indoor in-service pedestrian systems located in Italy are investigated. Operational Modal Analysis (OMA) procedures and dynamic identification techniques are used to quantify the residual capacity of the examined systems, including damage and material degradation, based on a single triaxial Micro Electro-Mechanical System (MEMS) accelerometer. The experimentally derived performance indicators and calibrated mechanical parameters for the examined structural system are assessed towards traditional design procedures, and further quantified with the support of Finite Element (FE) numerical model updating. A comparative analysis is carried out to explore the structural performance and safety levels of in-service LG slabs in regards to vibration comfort, deflection control and stress analysis.
{"title":"Rapid Safety Assement and Experimental Derivation of Damage Indexes for In-Service Glass Slabs","authors":"Chiara Bedon, S. Noè","doi":"10.47982/cgc.8.403","DOIUrl":"https://doi.org/10.47982/cgc.8.403","url":null,"abstract":"The mechanical performance of pedestrian structures attracts the attention of several studies, especially with respect to unfavourable operational conditions or possible damage scenarios. In terms of vibrations, for example, specific customer comfort levels must be satisfied, depending on the class of use, the structural typology, the involved materials, in addition to basic safety requirements. A special consideration should be given to in-service systems that are possibly affected by degradation or even damage, and thus potentially unsafe for pedestrians. In this regard, the availability of standardized non-destructive protocols for a reliable and rapid structural safety assessment may result in efficient support for diagnostic analyses. In this paper, 3 different laminated glass (LG) modular units belonging to 2 different indoor in-service pedestrian systems located in Italy are investigated. Operational Modal Analysis (OMA) procedures and dynamic identification techniques are used to quantify the residual capacity of the examined systems, including damage and material degradation, based on a single triaxial Micro Electro-Mechanical System (MEMS) accelerometer. The experimentally derived performance indicators and calibrated mechanical parameters for the examined structural system are assessed towards traditional design procedures, and further quantified with the support of Finite Element (FE) numerical model updating. A comparative analysis is carried out to explore the structural performance and safety levels of in-service LG slabs in regards to vibration comfort, deflection control and stress analysis.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125712871","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The analysis of load-bearing capacity and the determination of blast protection levels for ordinary glass windows and façade components in buildings is known to represent a design and research issue of crucial importance. In the same way, reliable methods to address this issue are mostly based on cost and management expensive experimental investigations on full-size samples. According to the tendency of recent years, this paper presents some of major outcomes of Finite Element (FE) numerical methods and simulations that have been explored in the framework of the GLASS-SHARD research project for glass windows and facades under explosion or soft-body impact. The attention is focused on the analysis of a Triple Glass Unit (TGU), so as to address the blast performance of a rather ordinary glass window for buildings characterized by the presence of multiple laminated glass (LG) layers, on one side, and by the presence of two interposed gas cavities. The TGU blast performance is investigated in terms of load-bearing capacity of single components, with respect to variations in the input blast loads (stand-off distance R, charge W, etc).
{"title":"Numerical Analysis of TGU Windows Under Blast – GLASS-SHARD Outlook","authors":"Chiara Bedon, Martin Larcher, A. Bez, C. Amadio","doi":"10.47982/cgc.8.450","DOIUrl":"https://doi.org/10.47982/cgc.8.450","url":null,"abstract":"The analysis of load-bearing capacity and the determination of blast protection levels for ordinary glass windows and façade components in buildings is known to represent a design and research issue of crucial importance. In the same way, reliable methods to address this issue are mostly based on cost and management expensive experimental investigations on full-size samples. According to the tendency of recent years, this paper presents some of major outcomes of Finite Element (FE) numerical methods and simulations that have been explored in the framework of the GLASS-SHARD research project for glass windows and facades under explosion or soft-body impact. The attention is focused on the analysis of a Triple Glass Unit (TGU), so as to address the blast performance of a rather ordinary glass window for buildings characterized by the presence of multiple laminated glass (LG) layers, on one side, and by the presence of two interposed gas cavities. The TGU blast performance is investigated in terms of load-bearing capacity of single components, with respect to variations in the input blast loads (stand-off distance R, charge W, etc).","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129863442","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
M. Engelmann, W. Wulff, T. Lorenz, Simon Frey, Laurenz Wernicke, Yangwen Zhang, T. Schauer, A. Bleicher
The worlds spectacular skylines host tall and slender buildings to create a maximum of office, residential and commercial space on a minimized footprint. These structures need to cope with increasing wind forces at height and are additionally affected by wind-induced vibration due to their lower natural frequencies. The resulting vibrations make users uncomfortable. Therefore, heavy tuned mass dampers are installed in structures and occupy valuable space especially in the costliest top-floors. As an example, Taipei 101’s steel damper is located between the 87th and 91st floor and weights astonishing 660 metric tons. This raises the need for additional reinforcement which increases cost and carbon footprint.Most buildings in expensive metropolises are cladded with remarkable glass facades. Therefore, we asked the question if it was possible to use the existing mass – more specifically the glass mass in a Double‑Skin Facade – to dampen the building’s movement, create a comfortable space for the user, exploit more floor area for the investor and finally to minimize the amount of building material to reduce carbon footprint for society. The idea was realized in a collaborative research effort of TU Berlin, BTU Cottbus-Senftenberg and Josef Gartner GmbH that resulted in a full-scale mock-up of a Double‑Skin Facade. Its outer skin can move laterally on a guide rail system. As the building starts to move, the facade's inner skin remains fixed to the base structure while the outer skin follows the building’s movement in a delayed manner due to its mass inertia. The fixed inner skin and the moveable outer skin are connected by a spring system that is tuned to the first natural frequency of the base structure. During the motion of the facade’s outer skin, the spring system redirects the relative movement and generates a stabilizing force for the base structure in the opposite direction. Additionally, an electrical machine is placed in between to provide an adjustable damping effect for semi-active and passive control. It also serves the purpose of a generator to study the opportunity to harvest energy. The paper shows the structural design options for the novel facade concept in the context of a project review of Double-Skin and Closed-Cavity Facades. The function of a full-scale mock-up, its fabrication and installation are described to show feasibility and ongoing challenges. First test results reveal a close match between theoretical assumptions and the applied testing. This engineering-driven and experimentally validated design opens a new field of architectural options in sustainable facade design which is focused on tuning physical parameters that affect the damping properties of the global structure.
{"title":"How to Exploit the Glass Mass for Damping a Building?","authors":"M. Engelmann, W. Wulff, T. Lorenz, Simon Frey, Laurenz Wernicke, Yangwen Zhang, T. Schauer, A. Bleicher","doi":"10.47982/cgc.8.425","DOIUrl":"https://doi.org/10.47982/cgc.8.425","url":null,"abstract":"The worlds spectacular skylines host tall and slender buildings to create a maximum of office, residential and commercial space on a minimized footprint. These structures need to cope with increasing wind forces at height and are additionally affected by wind-induced vibration due to their lower natural frequencies. The resulting vibrations make users uncomfortable. Therefore, heavy tuned mass dampers are installed in structures and occupy valuable space especially in the costliest top-floors. As an example, Taipei 101’s steel damper is located between the 87th and 91st floor and weights astonishing 660 metric tons. This raises the need for additional reinforcement which increases cost and carbon footprint.Most buildings in expensive metropolises are cladded with remarkable glass facades. Therefore, we asked the question if it was possible to use the existing mass – more specifically the glass mass in a Double‑Skin Facade – to dampen the building’s movement, create a comfortable space for the user, exploit more floor area for the investor and finally to minimize the amount of building material to reduce carbon footprint for society. The idea was realized in a collaborative research effort of TU Berlin, BTU Cottbus-Senftenberg and Josef Gartner GmbH that resulted in a full-scale mock-up of a Double‑Skin Facade. Its outer skin can move laterally on a guide rail system. As the building starts to move, the facade's inner skin remains fixed to the base structure while the outer skin follows the building’s movement in a delayed manner due to its mass inertia. The fixed inner skin and the moveable outer skin are connected by a spring system that is tuned to the first natural frequency of the base structure. During the motion of the facade’s outer skin, the spring system redirects the relative movement and generates a stabilizing force for the base structure in the opposite direction. Additionally, an electrical machine is placed in between to provide an adjustable damping effect for semi-active and passive control. It also serves the purpose of a generator to study the opportunity to harvest energy. The paper shows the structural design options for the novel facade concept in the context of a project review of Double-Skin and Closed-Cavity Facades. The function of a full-scale mock-up, its fabrication and installation are described to show feasibility and ongoing challenges. First test results reveal a close match between theoretical assumptions and the applied testing. This engineering-driven and experimentally validated design opens a new field of architectural options in sustainable facade design which is focused on tuning physical parameters that affect the damping properties of the global structure.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128957552","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Glass material has been widely used in modern architecture. Scratch-induced surface damage of aged monolithic glass panel leads to the strength degradation of material and thus threatens the glass safety. Therefore, in order to accurately evaluate the strength of aged glass elements, it is crucial to extract key damage features including the damage location and depth in a precise way. This study aims to develop a non-contact stage-wise scanning method to extract 3D damage characteristics on glass surface, which can further facilitate the investigation into the associated influences on the flexural strength of glass. Coaxial double ring tests on annealed glass specimens under various magnitudes of applied loads were performed, which aimed to explore the influence of the surface damage on the flexural strength. Monocular microscope equipped with an industrial camera was used to detect damage area throughout the glass panel in the first stage rapidly. It was then followed by a chromatic confocal scanner to precisely measure the damage depth within local damage area. The results via confocal microscope scanning were considered as the reference values. It shows that the proposed method can be a potentially alternative solution instead of confocal microscope for damage quantification.
{"title":"Non-Contact 3D Characterization System of Scratch-Induced Surface Damage on Monolithic Glass Panel","authors":"Zhufeng Pan, Jian Yang, Xing-er Wang, Yige Wang, Gang Li, Xianfang Jiang","doi":"10.47982/cgc.8.392","DOIUrl":"https://doi.org/10.47982/cgc.8.392","url":null,"abstract":"Glass material has been widely used in modern architecture. Scratch-induced surface damage of aged monolithic glass panel leads to the strength degradation of material and thus threatens the glass safety. Therefore, in order to accurately evaluate the strength of aged glass elements, it is crucial to extract key damage features including the damage location and depth in a precise way. This study aims to develop a non-contact stage-wise scanning method to extract 3D damage characteristics on glass surface, which can further facilitate the investigation into the associated influences on the flexural strength of glass. Coaxial double ring tests on annealed glass specimens under various magnitudes of applied loads were performed, which aimed to explore the influence of the surface damage on the flexural strength. Monocular microscope equipped with an industrial camera was used to detect damage area throughout the glass panel in the first stage rapidly. It was then followed by a chromatic confocal scanner to precisely measure the damage depth within local damage area. The results via confocal microscope scanning were considered as the reference values. It shows that the proposed method can be a potentially alternative solution instead of confocal microscope for damage quantification.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114112533","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
F. Ensslen, G. Schwind, J. Schneider, A. Beinert, Achour Mahfoudi, Elke Lorenz, Wiebke Herzberg, Michael Elstner, M. Poláková, Steffen Schäfer, C. Erban, Joachim Röhner, R. Sommer
For the design of façade and roof glazing, loads due to dead weight, climatic loads (IGU - pressure differences), wind and snow are well investigated and are considered in engineering practice. However, glass constructions are also ex-posed to thermally induced stresses due to direct solar irradiation. The standards and guidelines available so far, both nationally and at the European level, are partly outdated or contain only simplified instructions and specifications for calculating thermally induced stresses of façade and roof glazing. Within the research project, a variety of façade glazing configurations and additionally building-integrated (BIPV) glass-glass photovoltaic modules, for example as a façade cladding rear ventilated, are being investigated by means of numerical simulation and subsequent experimental validation with up-to-date German meteorological data. The purpose of the project is to reduce or prevent the occurrence of thermally induced glass breakage (thermal breakage) through European standardization. In this way, economic damage can be avoided. The present paper provides an insight into the two-years lasting joint research project, including the current status of science and technology, goals, structure and process, and descriptions of work packages. Results, such as the collection of the various influencing factors, meteorological data, and results from numerical simulations, will be presented after the project has finished at the end of September 2022.
{"title":"Joint Research Project (in progress): Draft Standard for Determining the Thermal Stress of Glass and Glass-Glass PV Modules (BIPV) in the Construction Industry","authors":"F. Ensslen, G. Schwind, J. Schneider, A. Beinert, Achour Mahfoudi, Elke Lorenz, Wiebke Herzberg, Michael Elstner, M. Poláková, Steffen Schäfer, C. Erban, Joachim Röhner, R. Sommer","doi":"10.47982/cgc.8.433","DOIUrl":"https://doi.org/10.47982/cgc.8.433","url":null,"abstract":"For the design of façade and roof glazing, loads due to dead weight, climatic loads (IGU - pressure differences), wind and snow are well investigated and are considered in engineering practice. However, glass constructions are also ex-posed to thermally induced stresses due to direct solar irradiation. The standards and guidelines available so far, both nationally and at the European level, are partly outdated or contain only simplified instructions and specifications for calculating thermally induced stresses of façade and roof glazing. Within the research project, a variety of façade glazing configurations and additionally building-integrated (BIPV) glass-glass photovoltaic modules, for example as a façade cladding rear ventilated, are being investigated by means of numerical simulation and subsequent experimental validation with up-to-date German meteorological data. The purpose of the project is to reduce or prevent the occurrence of thermally induced glass breakage (thermal breakage) through European standardization. In this way, economic damage can be avoided. The present paper provides an insight into the two-years lasting joint research project, including the current status of science and technology, goals, structure and process, and descriptions of work packages. Results, such as the collection of the various influencing factors, meteorological data, and results from numerical simulations, will be presented after the project has finished at the end of September 2022.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127017169","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
J. Vitkala, M. Klein, Daniel F. Schmidt, Senthil Vinodh
This contribution addresses the impact of tempering processes on the emissivity of LowE glass. The current status of a measurement series conducted at various tempering sites on different types of LowE glass is presented. Emissivity measurements using inductive eddy current sensors have been made on glass before and after tempering. The obtained data shows an improvement by factor 2 in emissivity depending on coating type. Effects from tempering recipes and the resulting emissivity homogeneity have been analyzed. Measurements also show significant worsening of the emissivity by the use of wrong tempering settings where too little convection occurs during heating that cause glass bending leading to the well-known white marks in the center of the glass along with significant loss in emissivity. Assessment of the glass emissivity properties as well as the negative effects of poor furnace recipe optimization on coatings were measured by eddy current systems, which rely on inductive methods for contact or non-contact real-time emissivity assessment. Comparison to thermographic images are shown and discussed. Finally, the status of measurement and analysis are summarized and the potentials to use of these phenomena are discussed.
{"title":"Insights into Emissivity Changes During Tempering Processes and Potential for Utilization","authors":"J. Vitkala, M. Klein, Daniel F. Schmidt, Senthil Vinodh","doi":"10.47982/cgc.8.457","DOIUrl":"https://doi.org/10.47982/cgc.8.457","url":null,"abstract":"This contribution addresses the impact of tempering processes on the emissivity of LowE glass. The current status of a measurement series conducted at various tempering sites on different types of LowE glass is presented. Emissivity measurements using inductive eddy current sensors have been made on glass before and after tempering. The obtained data shows an improvement by factor 2 in emissivity depending on coating type. Effects from tempering recipes and the resulting emissivity homogeneity have been analyzed. Measurements also show significant worsening of the emissivity by the use of wrong tempering settings where too little convection occurs during heating that cause glass bending leading to the well-known white marks in the center of the glass along with significant loss in emissivity. Assessment of the glass emissivity properties as well as the negative effects of poor furnace recipe optimization on coatings were measured by eddy current systems, which rely on inductive methods for contact or non-contact real-time emissivity assessment. Comparison to thermographic images are shown and discussed. Finally, the status of measurement and analysis are summarized and the potentials to use of these phenomena are discussed.","PeriodicalId":332145,"journal":{"name":"Challenging Glass Conference Proceedings","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123386821","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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