Sacrificial cladding design for blast mitigation using low density crushable core systems

The aim of this study is to define a simple approach to select an adequate sacrificial cladding configuration (front plate and crushable core parameters) to protect a given structure against a blast load. A simplified one-dimensional model, denoted, the Load-Cladding-Structure (LCS) model is investigated and the effect of the fluid-structure interaction (FSI), the loading rate (LR) and the sacrificial cladding-structure interaction are examined. Strong blast load and two low-density crushable cores are considered: (i) a polyurethane foam (PU), and (ii) a metallic beverage can (MBC). Small scale experimental results are analysed and compared to analytical models. This shows that: (i) the LCS model is a non-conservative model, (ii) both the FSI and the LR have to be considered, and (iii) the use of an adequate sacrificial cladding converts the hazardous blast load into a relatively lower pressure applied over a longer time span. Hence, simple steps are provided to select the front plate characteristics and the crushable core plateau stress and thickness, as a function of the blast load intensity and the structure properties.