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Trabecular bone possesses a complex hierarchical structure of plate- and strut-like elements, which is analogous to structural systems encountered in engineering practice. In this work, key structural features of trabecular bone are mimicked to uncover effective energy dissipation mechanisms under blast loading. To this end, several key design parameters were identified to develop a bone-like unit cell. A computer script was then developed to automatically generate bone-like finite element models with many combinations of these design parameters, which were simulated under blast loading. The optimal structure was identified and its performance was benchmarked against traditional engineered cellular structures, including those with hexagonal, re-entrant and square cellular geometries. The bone-like structure showed superior performance over its engineered counterparts using the peak transmitted reaction force and energy dissipation as the key performance criteria. [ABSTRACT FROM AUTHOR]

Re-entrant and honeycomb cellular structures have shown potential for mitigating the effects of extreme loadings such as those imposed by impacts and near-range air blast. However, these cellular geometries can buckle locally and collapse in the immediate vicinity of the loading, which can limit their effectiveness as a protective element. These deficiencies can be addressed by mimicking alternate, naturally occurring, cellular structures, including that of the porcupine quill, which is studied here. The quill possesses several distinct features that effectively counteract buckling and bending, and minimise weight. This study mimics several structural features of the quill to develop a novel cellular design for counteracting air blast loads such as those associated with detonations of high explosives. The performance of the bio-mimetic structure is benchmarked against traditional hexagonal and re-entrant designs, which have been documented in the archival literature. The quill-inspired structure offers more design freedom than the traditional cellular geometries. By iteratively mimicking several of the structural features of the porcupine quill, an optimal balance between local buckling and collapse can be realised, which minimises the reaction on the target below and maximises energy dissipation. [ABSTRACT FROM AUTHOR]

The main function of a building façade system is to provide comfort and protection to interior building spaces. In a blast event, façade components become the weakest part of a building and the blast-induced shock wave may breach the facade and injure building occupants due to flying debris. There is increasing popularity in the use of double-skin façade systems (DSFSs) in modern façade construction because of their energy efficiency advantages. In addition to their improved energy performance, DSFSs can increase the blast-resistant capacity of a building. However, due to the complex structural interactions between DSFSs and blast-pressure waves, there is a lack of design codes that account for the performance of DSFSs under blast loading. This paper reports on an experimental program of analogical DSFSs that consist of steel panels as opposed to glass panels, subjected to a 250 kg equivalent TNT charge weight at a stand-off distance of 52 m (250 kg@ 52 m). Three different DSFS compartments with varying ventilation areas were tested. Numerical analyses of the structural responses of a DSFS were then conducted based on the pressures recorded in the experiment. A comparative study was conducted on the blast performance of glass panels, based on the design procedures of current standards and numerical techniques. It was found that the current standards for double-glazed insulating glass (IG) units greatly overestimated the blast performance of DSFSs by simplifying the load-sharing factors. This paper further identifies the critical parameters of DSFSs when assessing their responses to blast pressures. [ABSTRACT FROM AUTHOR]