UBC Theses and Dissertations
Experimental and numerical investigation of a novel sandwich panel under free air blast loads Abdelsalam, Mohamed
For a long time, Humanity has been suffering from explosive attacks. These attacks mainly focused on essential infrastructure, which cost much money to rebuild. However, these structures can be effectively fortified using protective systems. Sandwich panels are commonly used as protective layers for underground structures. The front panel and interlayer are designed to mitigate the blast energy from reaching the back panel (the main structure). Traditionally, a sand layer has been used as a protective layer to absorb the blast energy. However, the sand layer has several shortcomings, including (1) rapid plastic compaction after a blast shot, (2) a heavyweight layer and, (3) difficult to control the density and water contents. In this research, a newly lightweight sandwich panel, named reinforced concrete (RC) panel - Helical springs- RC panel (RHR) sandwich panel, is proposed. RHR consists of RC panel attached to a number of helical springs and connected to RC panel (main structure). Numerical and experimental studies of the RHR under free air blast load are conducted. The performance of the RHR is compared to the Sand – RC panel (SR) and the RC panel – Sand – RC panel (RSR) protective systems against free air blast loads. SR consists of a sand layer on the top of the RC panel. The sand layer has the same depth as the front RC panel and helical springs interlayer of the RHR. Whereas, RSR uses the same configuration as RHR, except the helical springs are replaced with a sand layer. To effectively compare the performance of the three systems, an advanced Riedel-Hiermaier-Thoma (RHT) concrete model is calibrated to accurately simulate the post failure behavior of concrete panel under blast loads. The results show that the proposed RHT model can accurately model the damage level of the concrete panel under blast loads when compared with the experimental results. The result shows that RHR has superior performance in storing the applied energy elastically when compared with the other protective systems. Lastly, a parametric study is conducted to optimize the performance of RHR. The results emphasized that RHR is an effective and efficient protective system for the roof of shallow underground structures.
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Attribution-NonCommercial-NoDerivatives 4.0 International