A method for transforming a full computation of the effects of a complex-explosion scenario to a simple computation by ConWep

When a large amount of explosive that is stored inside a structure explodes, a blast wave is generated. The strength of the blast depends on both the explosive (type and weight) and the properties of the storing structure, since part of the blast energy is needed to destroy the structure. If one is to determine the dynamic load (e.g., pressure and impulse) that is exerted by the blast on a neighboring structure, he needs to conduct a full numerical simulation with a validated numerical code. If the amount of the stored explosive changes while the storing structure remains the same a new full hydrodynamic computation is required. In the present study, we present a method by which, for a given structure inside which explosive is stored, only a few full hydrodynamic computations with different amounts of explosive are required in order to obtain the resulted blast wave load on a neighboring structure that is located at different distances from the exploding structure for any amount of explosive between the minimal and the maximal amounts that were used in the full hydrodynamic computations. By means of the proposed method, the problem, which as mentioned above needs a full hydrodynamic computation, is replaced by an equivalent problem of the explosion of a bare hemispherical charge. The equivalent problem can be solved by means of an empirical model such as ConWep, which is very simple to apply. The solution of the equivalent problem results in identical peak pressure and peak impulse at close and far ranges from the explosion source and very similar pressure and impulse profiles at far ranges. The proposed method is demonstrated by an explanatory example in which the effect of an explosion inside an ammunition magazine on the surroundings is studied.