The damage of sequential explosions in reinforced concrete: Experimental and numerical investigation

The development of guidance technology has made it possible for the earth penetration weapons (EPWs) to impact the target repeatedly at a close range. To investigative the damage of single and sequential strike induced by the EPWs, experimental and numerical investigations are carried out in this paper. Firstly, a series of sequential explosion tests are conducted to provide the basic data of the crater size. Then, a numerical model is established to simulate the damage effects of sequential explosions using the meshfree method of Smoothed particle Galerkin. The effectiveness of numerical model is verified by comparison with the experimental results. Finally, based on dimensional analysis, several empirical formulas for describing the crater size are presented, including the conical crater diameter and the conical crater depth of the single explosion, the conical crater area and the joint depth of the secondary explosion. The formula for the single explosion expresses the relationship between the aspect ratio of the charge ranging from 3 to 7, the dimensionless buried depth ranging from 2 to 14 and the crater size. The formula for the secondary explosion expresses the relationship between the relative position of the two explosions and the crater size. All of data can provide reference for the design of protective structures. • The explosion mechanism of shelled charge in sequential strikes was analyzed. • The effects of coupling ability and the presence of the free surface on sequential explosion crater were analyzed. • The empirical formulas of single explosion conical crater were established. • The empirical formulas describing the size of secondary explosion conical crater were established.