SIMPLIFIED MODEL OF OVERPRESSURE LOADING CAUSED BY INTERNAL BLAST

The UFC standard assumes a uniform pressure distribution for internal blasts. However, the actual pressure field is non-uniform due to the limiting effects of walls. In this paper, an internal blast is simulated using AUTODYN’s Remap tool, and the laws governing distribution of blast load on the wall surface are studied. Based on the characteristics of the overpressure time history and the distribution of peak overpressure, the areas subjected to blast load are divided, and formulas for calculating peak overpressure, shock wave duration, gas pressure, and blow-down time for each region are proposed. A simplified model for blast loading is established and the influence of explosion height and confinement geometry is analyzed. The results show that the load distribution and blast load computational method in each region are different and the empirical formulas evaluating the blast load in different regions are fitted. Explosion height and confinement geometry have a great influence on peak overpressure, but less on impulse.