A New Analytical Prediction for Energy Responses of Hemi-Cylindrical Shells to Explosive Blast Load

Resumen

This study presents a new analytical model on the dissipation process of the initial total energy of the hemi-cylindrical shell subjected to the explosive blast load. The analytical formulation has been established using the energy method. The analytical predictions have been validated and found to be in excellent agreement with numerical simulations calculated by explicit finite element method (via LS-DYNA). The variational parameters considered are the shell thickness, elastic modulus, densities of the shell, and the positions of the detonation. Considering varieties of the parameters, the analytical and numerical results demonstrate that the pattern of vibrating deformations can be classified into two types according to the detonation positions. If the detonation position was at the midpoint of the width, there was no main frequency, whilst if the detonation position was at the edge of the width, the shell vibrated with a main frequency. It was also found from both analytical and numerical models that the total initial energy is inversely proportional to the thickness of the shell ( $T$ ), namely, the exact formula can be written as $\beta ={\rho }_{a}c/{\rho }_{s}T$ . Surprisingly, this study is the first to highlight that the total energy decreases with time by the exponential function, and the exponential ratio ( $\beta$ ) is inversely proportional to the thickness of the shell as well.