Double blast loadings of clamped square steel plates

This paper presents a combining experimental, numerical, and analytical efforts to elucidate the resultant effect of synchronised double blast loadings on square steel plates. Blast tests were performed to investigate the effect of the distance between the two identical charges upon the large inelastic deformation of fully-clamped steel plates at various standoff distances. Detailed three-dimensional finite element simulations using LS-Dyna were performed to provide insights into the equal blast wave collision and transient response of the ductile plates under the double blast loading. An analytical model was developed to predict the large inelastic deflection of the fully-clamped thin plate under either pulse pressure loading or impulsive loading (an instantaneous zero-period impulse). Experimental results found that splitting a 1kg TNT into 2 × 0.5 kg TNT (with a certain separating distance) would lead to greater permanent inelastic deformation of the ductile thin plates (by up to 19.6%). Both numerical and analytical results were validated against experimental data. Results from the parametric study showed that an optimum charging distance exists for maximised plate deflection under a given TNT mass and standoff distance. The results presented in this work shall be useful for evaluating the hazards of multiple blast loadings or for demolition applications.