A finite element model for simulation of delaminations in laminated glass panels subjected to cyclic thermal loading

层压玻璃板由至少两个用聚合物夹层材料胶合的玻璃部件组成。薄夹层（0.38 - 2.28 mm）通常由聚乙烯醇缩丁醛（或PVB）组成，而玻璃层基本上厚3-25 mm。如果玻璃板最终破裂，层压件确保剩余承载能力。在结构和汽车工程，海军建筑，飞机工业和光伏电站的应用。特别是在户外应用中，随着温度暴露的增加，由于分层发生损坏演变。玻璃和聚合物中间层之间的结合力在使用多年后可能会下降，从而影响可用性和剩余承载能力。该项目涉及开发一个模型来描述由于循环热负荷引起的夹层玻璃板分层的开始和传播。这就需要一系列的基础研究任务。由于层合板的结构具有完全不同的组分行为，因此产生复杂的应力场，现有的数值模型不能应用。一个二维模型，这只需要一个分数的计算时间相比，完全三维离散化或所谓的FE 2模型，是研究的基础。对于它的耦合热力学边值问题和运动学以及本构行为来描述传播脱层必须开发。为了解释几千个周期，时间多尺度模型是工作的进一步部分。参数研究与几个数量的变化（材料选择和材料参数的夹层，缺陷和初始曲率的影响）引起结构的改进。夹层安全玻璃越来越多地用作各种技术领域的设计元素。该研究项目旨在为这一重要结构元素的力学理解提供基础性贡献。

Laminated glass panels consist of at least two glass components glued with polymeric interlayer materials. Thin inter layers (0,38-2,28 mm) often consist of polyvinyl butyral (or PVB) whereas the glass layers are with 3-25 mm essentially thicker. The laminate ensures the residual carrying capacity if the glass plates are ultimately broken. Applications are given in structural and automotive engineering, naval architecture, aircraft industries and for photovoltaic plants. Especially in outdoor applications with temperature exposure increased, damage evolution due to delamination occurs. Decreasing bonding between glass and polymer interlayer may occur after years of usage and thus influences usability and residual carrying capacity.The project deals with the development of a model to describe initiation and propagation of delaminations in laminated glass panels due to cyclic thermal loading. This requires a series of basic research tasks. Due to the structure of the laminate with entire different behavior of the constituents and hence resulting complicated stress fields existing numerical models cannot be applied. A two-dimensional model, which requires only a fractional amount of computing time in comparison with fully three-dimensional discretizations or so-called FE2-models, is basis of the research. For it the coupled thermomechanical boundary value problem and the kinematics as well as constitutive behaviour to describe propagating delaminations have to be developed. To account for several thousand cycles a time-multiscale model is further part of the work. Parameter studies with a variation of several quantities (material choice and material parameters for the interlayers, influence of imperfections and initial curvatures) give rise to structural improvements. Laminated safety glass is increasingly used as design element in various technical fields. The research project is to provide fundamental contributions for the mechanical understanding of this important structural element.