Redundancy of reinforced glass beams : temperature, moisture and time dependent behaviour of the adhesive bond

The most important aspect of the reinforced glass beam concept, which provides ductility and redundancy for structural glass beams, is the adhesive bond between glass and reinforcement. To guarantee structural safety, this adhesive bond has to service under all conditions. The effects of elevated temperature, moisture exposure and load duration on the adhesive bond, have separately been investigated through three series of bending tests on 1.5 m reinforced glass beam specimens. A first series has been tested at 60 C; a second series has been tested after 8 weeks of salt-water-spraying; and a third series has been loaded until initial failure whereupon it has been left statically loaded for at least 72 hours. The results show that the reinforced glass beam concept is a redundant system which shows, dependent on the applied adhesive, a significant residual strength even at extreme temperature and moisture conditions, and for a significant period of time

Finite-Element Numerical Simulation of the Bending Performance of Post-Tensioned Structural Glass Beams with Adhesively Bonded CFRP Tendons

In 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

Finite-element analysis of post-tensioned SG-laminated glass beams with mechanically anchored tendons

Based on past experimental research results, this paper aims to investigate the structural performance of laminated glass beams with post-tensioned, mechanically anchored tendons, via extended finite-element (FE) simulations. The post-tensioned glass beam concept offers the advantage of providing a certain amount of initial compressive stresses in glass, hence resulting in a marked increase of the initial fracture load and in a rather appreciable redundancy, compared to typically brittle, unreinforced glass beams. Due to the presence of the post-tensioned tendons, a significant level of residual strength can also be guaranteed, thus resulting in a structurally efficient and safe design concept. In order to fully optimize the expected resistance and redundancy potentialities, however, careful consideration should be paid for a multitude of geometrical and mechanical aspects. In this research contribution, both full 3D and shell models are implemented for post-tensioned laminated glass beams. Based on validation of these FE models towards the past full-scale experimental results, the effects of several mechanical parameters are emphasized (e.g. steel tendon percentage, level of the applied pre-stressing force and the presence of possible geometrical imperfections) under room temperature and quasi-static loads. It is expected, based on the current study, that the examined design concept could be further developed and optimized

Editorial

The 7th edition of Challenging Glass is unlike any of the previous events in the 12-year history of the conference. Due to the ongoing corona pandemic, the on-location event has been replaced by an online webinar, featuring a keynote by Chikara Inamura and a small selection of short paper presentations. We are proud to, nevertheless, be able to present to you these Challenging Glass Conference 7 Proceedings, which are published Open Access in collaboration with TU Delft Open. The proceedings contain more than 50 papers, by glass experts from around the world, while another 20 papers are published in collaboration with the Springer journal Glass Structures & Engineering. We appreciate the efforts by all authors in these extraordinary times immensely. Organising this webinar and editing the conference proceedings has once again been an enjoyable experience, albeit different from previous ones. We would like to acknowledge all authors for their contributions, all scientific committee members for their valuable reviews, our esteemed keynote speaker for his inspiring presentation and of course all webinar participants for their interest in this event. We are grateful to our Platinum Sponsors Saint-Gobain and Eastman, as well as our Gold and Silver Sponsors for making this event possible. In addition, we would like to thank our hosting institution, Ghent University, particularly Shahryar Nategh for his support in compiling the conference proceedings. We wish you an enjoyable webinar and we trust you will encounter inspiring publications in these proceedings

Experimental and numerical analysis of thick embedded laminated glass connections

Laminated glass components are usually realized by bonding glass plates using interlayer polymers that develop adhesion forces during lamination. Recently, these adhesion forces have been used also to realize special adhesive connections for structural glass components and assemblies. The typical example of such a joining technique is conventionally known as \u201cembedded laminated connection\u201d, where a metal insert is encapsulated in multi-ply laminated glass components. In this study, careful consideration is paid for the investigation of the mechanical behaviour of embedded laminated connections with thick metal insert. To this aim, small-scale laboratory tests, Finite Element (FE) numerical models and analytical considerations are presented. Firstly, the results of experimental investigations at different temperatures are discussed, giving evidence of the geometrical and mechanical parameter effects on the so observed performances. It is observed, in particular, that the temperature markedly affects not only the maximum load carrying capacity but also the failure mode of the studied connection typology. Non-linear numerical simulations are then developed in ABAQUS on refined FE models, able to account for the geometrical and mechanical properties of the reference connection specimens. Further analytical considerations are also presented, in support of the observed experimental findings. It is shown, in particular, that as far as high temperatures are not attained, the mechanical performance and failure mode of the examined connections is strictly related to glass breakage. In addition it is also observed that at high temperature, failure mode (i.e. bubble formation) and failure location are in line with the expectations. Rather close correlation can be also found for the same embedded connections between test results, FE numerical simulations and analytical assumptions