Papers by Keyword: Laminated Glass

Abstract: Glass façades have become a prominent feature in modern architecture, offering aesthetic appeal and abundant natural light. However, in regions exposed to severe weather conditions, particularly during storms, glass façades are vulnerable to damage from wind-borne debris. The impact of such debris can compromise the structural integrity of the façade, leading to potential safety hazards. Despite the significant threat posed by wind-borne debris to the safety and performance of glass façades, the behavior of these materials under impact is not extensively studied. This study presents a comprehensive numerical analysis of the impact behavior of laminated glass panels subjected to debris typically propelled by strong wind forces, using LS-DYNA^®. The simulation models the interaction between wind-borne debris and glass panels of varying debris masses. Mechanical behavior of the glass is incorporated using fracture mechanics to simulate cracking and failure under impact. A range of impact scenarios is considered, including variations in debris mass, impact velocity, and impact locations, to replicate real-world conditions as accurately as possible. The numerical model integrates material properties, layer configurations, and impact conditions to closely reflect actual scenarios. In this study, wooden blocks of different masses are impacted on the laminated glass panels at varying locations and impact velocities. The results reveal the critical factors influencing the glass façade's response, such as the velocity of the incoming debris and the material strength of the glass. This study offers valuable insights for improving the safety and durability of glass façades. Thus, by understanding the complex dynamics of glass response to wind-borne debris, the study contributes to the development of more resilient architectural and structural systems, leading to better risk management strategies for buildings in areas prone to extreme weather events.

Abstract: This contribution shows the effectiveness of a simple mixed Finite Element Model (FEM) for simulating the mechanical behavior of structural Laminated Glass (LG) beams, by numerically reproducing several laboratory tests of small LG specimens taken from literature. The proposed mixed model adopts small displacements and Euler-Bernoulli beam hypotheses and assumes glass layers displacements and polymeric interlayer shear actions as independent fields. Numerical simulations show that such a simple model is able to correctly reproduce LG specimens’ initial stiffness and first peak strength and can be adopted for design purposes of LG elements at a larger scale

Abstract: Laminated glass is a structural element used extensively in a reconstruction of existing building structures because of its transparency and simplicity. When using laminated glass as a glass staircase, balustrades, transparent flooring, facades or other structural elements, it is advisable to consider the shear interaction of individual glass panes in the cross-section. A conservative approach where the glass panes shear interaction is not considered, is uneconomical. This interaction depends on the properties of polymeric interlayers used in lamination process. Various commercial products based on PVB (polyvinyl butyral), EVA (ethylene vinyl acetate), ionomer, or thermoplastic polyurethane (TPU) are used. Stiffness of polymers depends on temperature and duration of a load. Interlayers exhibit the viscoelastic properties and temperature dependency usually described by the generalized Maxwell model and WLF model (Williams-Landel-Ferry). Parameters of these models are the most effectively determined by Dynamic Mechanical Thermal Analysis (DMTA), where the material is cyclically loaded at different frequencies and temperatures. Material parameters were found by DMTA in shear for PVB type of interlayer Trosifol® BG R20. In addition, the experimental quasi-static loading tests in shear were performed at different loading rates and at various temperatures. These experimental stress-strain diagrams were compared to the theoretical stress-strain relations obtained from Maxwell model with material parameters based on DMTA testing. All tests were performed in Klokner Institute CTU in Prague.

Abstract: When looking at current architecture, we can notice large glass facades and shop windows. These elements are usually made of laminated glass panes with polymeric interlayer between and the task of shear forces transfer is the subject of a current survey especially in case of accidental load cases. It essentially depends on polymer material stiffness, which is temperature, load duration and loading rate dependent. A lot of different polymeric interlayers with different properties are available on a market but their experimentally determined material properties with respect to the load duration and temperature are not mostly specified. Structural engineers tend to design laminated glass structural elements on the safe side and do not take the interlayer stiffness into account. This leads to uneconomical and robust glass bearing members. In case of accidental load verification, shear stiffness of used interlayers plays a significant role. This paper is focused on two types of PVB (polyvinyl-buthyral interlayers) experimental investigation under various temperature and loading rate conditions.

Abstract: Based on GB/T 5137.1-2002 experiment specification, the finite element model of head-form impacting laminated glass for automotive windscreens is set up in this paper. According to Finite Element Analysis results of laminated glass with different structure and further analyzing impact property and mechanism of laminated glass , the influence rule of the structure of the laminated glass on the mechanical behavior is discussed. (H)

Abstract: Properties of laminated glass comprising two or more sheets of glass are greatly affected by the composite action of these panes which is influenced by material properties of used interlayer. Generally plastic foil or cast resin is used as the interlayer in lamination process. Laminated glass has been experimentally investigated in the laboratory condition in a four-point bending test on several kinds of interlayers in combination with variable thickness of the annealed glass. This paper establishes the so-called effective bending thickness according to standard method and presents comparisons with experimentally determined values.

Abstract: Laminated glass has been developed to improve the impact resistance of brittle glass sheets and to prevent injuries and collapse of glass members. The goal of this contribution is to briefly introduce a finite element model based on the refined plate theory by Mau that can describe the response of laminated glass plates without the need for fully resolved three-dimensional simulations. Each layer is considered to behave according to the Reissner-Mindlin kinematics, complemented with membrane effects and the von Karman assumptions. The compatibility of independent layers is enforced by nodal Lagrange multipliers. Predictions of the finite element model, obtained with a MATLAB-based program LaPla (Laminated Plates) developed by the authors, are compared with simplified monolithic and layered limits and a semi-analytical solution.

Abstract: In order to research the influence of the parameters of laminated windshield glass to pedestrian head injuries in vehicle-pedestrian accident, the adaptive response surface method (RSM) was utilized to optimize the key parameters of the laminated glass i.e. the elastic modulus, yield strength, density and the glass thickness, in which the pedestrian head injury criteria (HIC) and glass crack radius were setting as the objective function. A set of glass parameters was obtained which was the most beneficial to the pedestrian protection. The optimization may provide theory basis for the design and research of PVB laminated windshield.

Abstract: Laminated glass is widely used to enhance structural functions. The impact fracture behavior of laminated glass is more complicated than that of single glass, because of the combined influences of the large deformation and delamination strengths. In this study, the impact fracture behavior of a laminated glass plate intended for the outside surface of a modern building has been studied by numerical simulations and experiments. This fracture simulation was calculated using a Discrete Element Method (DEM) based on non-continuum mechanics. The laminated glass structures have been optimized for attaining maximum durability against impact fracture based on the response surface method. In the optimum problem, the tensile strength of the interlayer and the adhesive strength between two pieces of glass and the interlayer are taken as the design variables. From the results of the optimization, it has been observed that the laminated glass difficult to break in the case that the tensile strength was high and that the adhesive strength was a little light. The penetration performance of an optimized laminated glass plate was noticeably better in comparison with a commercial laminated glass plate.

Abstract: The paper presents a generic design study for a 2500 square meter, 4-storey embassy building. It is designed to resist blast loads from an assumed Design Basis Threat (DBT) that is provided by the owner. The building structure consists of reinforced concrete columns, beams and slabs supported on pile foundations. The exterior walls are concrete block with stone veneer. The windows are double glazed with aluminum frames. The building is situated within a compound with a perimeter wall. There is no basement.