Abstract:ness equal only to the total thickness of glass layers. For the upper bound it is more correct to assume the true monolithic model. 2 Note that the interval between the monolithic and layered limit can be reduced by including the effects of geometric nonlinearity, see (Vallabhan et al., 1987).
Latin American Journal of Solids and Structures 12 (2015) 1158-1181A. Zemanová et al. / Finite element model based on refined plate theories for laminated glass units
“…The simulations of head impact on the laminated windscreen have been performed for operation temperatures of +20 to −30 °C without taking the influence of the additional energy stream coming from the heating system into account. The numerical description of the modelling process was based on the information contained in the publications [ 10 , 29 , 30 , 31 , 32 ]. Sequentially for the temperature range of 30–0 °C the course of phenomena occurring during the impact has been analysed, taking into account the influence of local changes in the polymer structure under the influence of air blow coming from the windscreen heating system.…”
Section: Simulation Of Head Impact On the Laminated Windscreen In Varied Temperature Rangementioning
Statistically, road accidents involving pedestrians occur in the autumn and winter months, when outdoor temperatures reach −30 °C. The research presented in this paper investigates the impact of a pedestrian’s head on laminated windscreen, taking into account the effects of external temperature, heating of the windscreen from the inside, and fatigue of the glass. The automotive laminated windscreen under study is made from two layers of glass and a Polyvinyl Butyral (PVB) resin bonding them together. PVB significantly changes its properties with temperature. The Finite Element Method (FEM) simulations of a pedestrian’s head hitting the windscreen of an Opel Astra II at <−30 °C, +20 °C> were performed. The obtained Head Injury Criterion (HIC) results revealed an almost twofold decrease in safety between +20 °C and −20 °C. The same test was then performed taking into account the heating of the windscreen from the inside and the fatigue of the glass layers. Surprisingly, the highest HIC value of all the cases studied was obtained at −30 °C and heating the windscreen. The nature of safety changes with temperature variation is different for the cases of heating, non-heating, and fatigue of glass layers. Glass fatigue increases pedestrian safety throughout the temperature range analysed.
“…The simulations of head impact on the laminated windscreen have been performed for operation temperatures of +20 to −30 °C without taking the influence of the additional energy stream coming from the heating system into account. The numerical description of the modelling process was based on the information contained in the publications [ 10 , 29 , 30 , 31 , 32 ]. Sequentially for the temperature range of 30–0 °C the course of phenomena occurring during the impact has been analysed, taking into account the influence of local changes in the polymer structure under the influence of air blow coming from the windscreen heating system.…”
Section: Simulation Of Head Impact On the Laminated Windscreen In Varied Temperature Rangementioning
Statistically, road accidents involving pedestrians occur in the autumn and winter months, when outdoor temperatures reach −30 °C. The research presented in this paper investigates the impact of a pedestrian’s head on laminated windscreen, taking into account the effects of external temperature, heating of the windscreen from the inside, and fatigue of the glass. The automotive laminated windscreen under study is made from two layers of glass and a Polyvinyl Butyral (PVB) resin bonding them together. PVB significantly changes its properties with temperature. The Finite Element Method (FEM) simulations of a pedestrian’s head hitting the windscreen of an Opel Astra II at <−30 °C, +20 °C> were performed. The obtained Head Injury Criterion (HIC) results revealed an almost twofold decrease in safety between +20 °C and −20 °C. The same test was then performed taking into account the heating of the windscreen from the inside and the fatigue of the glass layers. Surprisingly, the highest HIC value of all the cases studied was obtained at −30 °C and heating the windscreen. The nature of safety changes with temperature variation is different for the cases of heating, non-heating, and fatigue of glass layers. Glass fatigue increases pedestrian safety throughout the temperature range analysed.
“…constant K: update internal forces from (22) and Maxwell chain stresses from (25) constant ν: update internal forces from (27) and Maxwell chain stresses from (28) Table 1: Overview of finite element models of laminated glass beams with viscoelastic interlayer.…”
Section: Comparison Verification and Validationmentioning
confidence: 99%
“…As the next step, we will enhance our elastic finite element solver for laminated glass plates [28] with viscoelastic effects, closely following the formulations developed in this paper. Subsequently, we would like to extend the formulation to post-critical state, by incorporating glass fracture into the layer-wise formulation.…”
Section: Comparison With Simplified Elastic Solutionmentioning
confidence: 99%
“…The differences in the mechanical results of the corresponding models will be studied in detail and verified against detailed finite element simulations, with the goal to determine the simplest, but still sufficiently accurate, formulation that is suitable for the generalization of elastic models of laminated glass plates [28] to the viscoelastic regime. The rest of the paper is organized as follows.…”
Laminated glass elements, which consist of stiff elastic glass layers connected with a compliant viscoelastic polymer foil, exhibit geometrically non-linear and time/temperature-sensitive behavior. In computational modeling, the viscoelastic effects are often neglected or a detailed continuum formulation typically based on the volumetric-deviatoric elastic-viscoelastic split is used for the interlayer. Four layerwise beam theories are introduced in this paper, which differ in the non-linear beam formulation at the layer level (von Kármán/Reissner) and in constitutive assumptions for the interlayer (a viscoelastic solid with the time-independent bulk modulus/Poisson ratio). We perform detailed verification and validation studies at different temperatures and compare the accuracy of the selected formulation with simplified elastic solutions used in practice. We show that all the four formulations predict very similar responses. Therefore, our suggestion is to use the most straightforward formulation that combines the von Kármán model with the assumption of timeindependent Poisson ratio. The simplified elastic model mostly provides response in satisfactory agreement with full viscoelastic solutions. However, it can lead to unsafe or inaccurate predictions for rapid changes of loading. These findings provide a suitable basis for extensions towards laminated plates and glass layer fracture, owing to the modular format of layerwise theories.
“…Although using Lagrange multipliers to account for the connection between adjacent layers is more flexible, see [4], we introduce stiff kinematic constraints for their simplicity. The relative vertical displacements of the layers are constrained by…”
Section: Finite Element Model Of the Three Layer Beammentioning
In this contribution, a methodology for calibration and validation of a finite element model for dynamic response of laminated glass units with viscoelastic interlayer is proposed. The model is based on a refined theory in which the adjacent layers are connected by kinematic constrains ensuring the inter-layer compatibility. The time-dependent behavior of the interlayer is accounted for by the generalized Maxwell model. The resulting system is solved by the Newton method with consistent linearization and allows for quantification of natural frequencies and eigenshapes. The calibration of the generalized Maxwell chain exploits the experimental master curve obtained from the rheometer test while the analysis of the dynamic response of glass beam serves for model validation.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.