Evaluation of the Potential of Cladding to Mitigate Blast Effects on the Supporting Structure

Abstract

Cladding components are critical when designing a building to resist blast loads, as they are the first to receive the applied airblast pressure. A recent trend is to design them in order to reduce the blast pressure transferred to the supporting structure, thus minimizing the overall load demand and consequences to the building frame. Therefore, it is desirable to develop a generally applicable method for evaluating the cladding performance in terms of blast pressure mitigation. In the present study, a methodology for calculating this mitigation potential is proposed, employing the dynamic load factor (DLF) of a dimensionless single-degree-of-freedom (SDOF) model subjected to blast for a variety of pressure and impulse combinations. The DLF of multiple SDOF analyses is used to calculate an overall indicator for the mitigation potential of the corresponding cladding. To further demonstrate the proposed methodology, four steel cladding types are analyzed, and their mitigation potential is mapped into their pressure–impulse diagrams. Furthermore, the effects of the activated mechanisms of plastic energy absorption and inertial resistance are presented through performance observations for the different geometry and boundary configurations of the four cladding types. Among the four cladding types, the best-and worst-performing ones were found to be a thick and a thin monolithic plate, respectively, while the performance of sandwich-type panels was in between. Generally, the analysis results suggest that the increased mass and plastic dissipation in the cladding are beneficial for the building frame, while increased stiffness may overload the building frame.