Due to the increasing use of load-bearing glazing in structural engineering, the residual load-bearing capacity of laminated glass is increasingly coming into focus. This is currently assessed exclusively on the basis of large-scale component tests. However, this approach is associated with high costs, a great deal of time and the use of materials. One way to save these resources is to theoretically characterize the residual load-bearing capacity. However, a the moment there is no reliable calculation model. In order to develop such a model, it first makes sense to divide the residual load-bearing behavior into three mechanisms: the behavior of the polymer interlayer, the bond between the film and the glass, and the interaction of the glass fragments or the fracture edges. The subject of this work is the characterization of the interlayer material polyvinyl butyral (PVB), which can be classified as an amorphous thermoplastic. To this end, the material is investigated experimentally and described mechanically. The work can therefore be roughly divided into an experimental part and a modeling part. The modeling part is supplemented by some engineering approaches. In the experimental part of the work, uniaxial tensile tests up to failure, relaxation tests and cyclic tests are carried out, in each case at room temperature. Strain rates, load levels and load reversal points are varied. As part of the subsequent modeling, a thermodynamically consistent material model of finite, non-linear viscoelasticity is constructed. The structure of the model is represented by a discrete spectrum of three networks, each with several Maxwell elements described by different potential and viscosity functions. The individual viscosity functions are constructed in such a way that they can represent the time-dependent mechanisms of the material. This generally formulated model is then reduced to the uniaxial stress state under the assumption of incompressible material behavior and implemented numerically. Following on from this, the various material parameters of the potential and viscosity functions are calibrated using the test data from the experimental part of the work. The results show a very good agreement between simulation and experiment, i.e. the model is very well suited to reproduce the time-dependent behavior of PVB at room temperature up to large deformations. The modeling section is supplemented by three engineering approaches. Firstly, a method is presented for using relatively short tests to infer the long-term behavior of a polymer under large deformations and to model it without taking the time dependency into account. In addition, a simplified analytical approach for modeling the residual load-bearing capacity of laminated safety glass made of coarse breaking glass with an intermediate layer of PVB is presented. This approach is based on a simplified version of the previously constructed material model. Finally, a resistance value for PVB under uniaxial loading is calibrated based on the failure tests. Overall, the construction of this material model for PVB and the engineering approaches derived from it represent an important milestone on the way to a numerical residual load-bearing capacity model. With the help of this material model, it is not only possible to accurately describe the behavior of PVB at room temperature, but also to better characterize other necessary material parameters such as the bond between glass and interlayer.    «

Due to the increasing use of load-bearing glazing in structural engineering, the residual load-bearing capacity of laminated glass is increasingly coming into focus. This is currently assessed exclusively on the basis of large-scale component tests. However, this approach is associated with high costs, a great deal of time and the use of materials. One way to save these resources is to theoretically characterize the residual load-bearing capacity. However, a the moment there is no reliable calcu...    »