考虑开裂层表征和残余作用的结构玻璃开裂后性能预测模型研究

Post-breakage performance is demanded for structural glass as loading bearing elements to guarantee the ductility after glass layer accidentally breaks. Limited report concerning the post-breakage behavior of structural glass as well as its evolution of load bearing mechanism can be found so far. It is also found that the characterization approach for the cracked glass and its further effect on the post-breakage performance is not located. The model for predicting the post-breakage performance of structural glass cannot be established according to such knowledge gap. Based on the fundamental principles and techniques of glass materials and structures, material science, computational geometry and structural engineering, this proposal aims to fill the following knowledge gaps: the fracture morphological features and the spatial-temporal distribution law of the residual strain energy in the cracked thermally tempered glass; the refined numerical model of the cracked structural glass using both voronoi tessellation and combined finite and discrete element method, which is capable of reproducing the characteristics and remaining effects of cracked glass in a quantitative description manner; the characterization approach for cracked glass as well as the post-breakage behavior and the evolution of load bearing mechanism considering the further effects by cracked glass. Finally, the model for predicting the post-breakage performance of structural glass which can quantitatively describe the effects by key factors will be proposed. This work can thus be of great help for improving the safety design of structural glass and its future application.

玻璃偶发碎裂后，作为结构承力构件的结构玻璃需保证有足够的开裂后性能来满足延性需求。目前结构玻璃开裂后行为及承载机制演变规律研究匮乏，开裂层表征和残余作用对开裂后性能的作用机理和规律亦尚未明确，难以支撑和提出可靠的结构玻璃开裂后性能预测模型。本项目基于玻璃材料与结构，采用材料科学、计算几何学、结构工程等学科的基础理论和技术手段，1)通过现代测量和计算几何方法，研究热钢化玻璃裂纹拓扑及残余应变能的时空分布规律，建立开裂层表征重塑方法；2)结合裂纹维诺拓扑重构技术和组合有限离散元法，构建可量化描述开裂层表征并定位其残余作用的结构玻璃精细化开裂后数值模型；3)通过试验研究和数值模拟技术，研究考虑开裂层表征和残余作用的开裂后行为及承载机制演变规律。最终提出可量化描述关键因素作用的结构玻璃开裂后性能预测模型，为结构玻璃安全设计方法和工程应用提供理论依据和技术支持。

结构玻璃开裂后行为相关研究匮乏，开裂层表征和残余作用对开裂后性能的作用机理和规律亦尚未明确，目前尚无可靠的结构玻璃开裂后性能分析模型。项目通过碎裂试验和计算机视觉方法，测定了81组单片玻璃和48组夹层玻璃在钢化应力（60~105 MPa）、玻璃厚度（6~12 mm）、中间层材料（聚乙烯醇缩丁醛PVB和离子性中间膜SG）、起裂位置等因素影响下的裂纹拓扑形式，明确了碎片和残余应变能空间分布变化规律，探明了各因素影响下的开裂玻璃膨胀效应和相应的等效弹性模量范围。基于等效温度荷载理论和夹层板理论，建立了夹层玻璃开裂后初始变形模型。随后，基于控制碎片密度和近邻距离的规则，提出一种创新的碎片形心布设手段，并结合Voronoi形态分布规律，实现对钢化玻璃裂纹形态的高精度随机重构，与真实裂纹形态的统计偏差控制在5%以内。随后，采用有限离散单元法建立夹层玻璃开裂后数值模型，可精确分析开裂后行为。通过对单轴/双轴拉伸、板构件受面外荷载、梁构件受面内/面外荷载等工况的参数分析，明确了开裂层表征和残余作用下的结构玻璃开裂后行为规律。