The response of glass window systems to blast loadings: An overview

The failure of glass windows in terrorist bombing attacks and accidental explosion incidents has been cited as one of the major causes to the vast casualties. Many studies have been carried out to investigate the response and vulnerability of glass windows against blast loadings. These include laboratory and field tests that have been carried out to experimentally study glass window performance under explosion scenarios and development of analytical and numerical models to analyze and predict glass window responses. This article reviews literatures on the studies of the response of glass window systems to blast loadings. Over 100 papers and documents that are available in the open literature are reviewed. The background and history of the studies on the topic are also briefed. Understandings about the dynamic material properties of glass and available material models are summarized. Popularly used analysis methods and design standards for monolithic and laminated glass windows are outlined, and their accuracies are discussed. Recent studies including analytical solution, numerical simulation, and experimental investigations on glass window systems are summarized. Mitigation measures for blast-resistant windows are also briefly discussed

Performance of TGU Windows under Explosive Loading

Glass windows and facades are very popular in buildings, both in the form of traditional partitions and novel adaptive skins. There, given a series of intrinsic material features, special care should be spent at the design stage, so as to ensure appropriate fail-safe requirements, especially in presence of extreme design loads such as impacts. Even more attention is required for complex glass assemblies such as Triple Glass Units (TGUs), where the interaction of multiple components (i.e. the glass layers and the bonding foils, with the framing members) as well as the presence of gas cavities can further affect the dynamic response of these sys-tems. In this paper, major outcomes of a research project in progress for the per-formance assessment of TGU windows under explosive loading are reported

Large increase in fracture resistance of stishovite with crack extension less than one micrometer

The development of strong, tough, and damage-tolerant ceramics requires nano/microstructure design to utilize toughening mechanisms operating at different length scales. The toughening mechanisms so far known are effective in micro-scale, then, they require the crack extension of more than a few micrometers to increase the fracture resistance. Here, we developed a micro-mechanical test method using micro-cantilever beam specimens to determine the very early part of resistance-curve of nanocrystalline SiO2 stishovite, which exhibited fracture-induced amorphization. We revealed that this novel toughening mechanism was effective even at length scale of nanometer due to narrow transformation zone width of a few tens of nanometers and large dilatational strain (from 60 to 95%) associated with the transition of crystal to amorphous state. This testing method will be a powerful tool to search for toughening mechanisms that may operate at nanoscale for attaining both reliability and strength of structural materials