Explosions in Complex Geometries — A Comparison of Several Approaches

Abstract

For the design and calculation of structures loaded by air blast waves, especially from inside the structure, assumptions on the applied load are needed. This paper presents several simulation methods for the air blast loading of structures and their ability to be used for complex geometries. Experimental-analytical pressure-time functions of spherical load conditions applied to the structure by disregarding the air are not applicable in such cases because they do not account for reflections, shadowing and channelling effects. Fluid calculations, which model also the solid explosive, are very expensive due to the extremely small elements for the explosive and the air nearby. This paper therefore presents a review of a well-known simulation method, which uses a balloon with compressed air instead of the explosive. A procedure is developed which makes it possible to determine the overpressure of such a balloon for a given size of the explosive more accurately than before. The pressure-time function and the impulse-distance function of calculations using this method show good correspondence with experimental-analytical data. The functioning of the method is verified against experimental results.