Research on the Dynamical Behavior of Sand/Steel Composite Structures Under Confined Explosion

Abstract

Previous research has shown that using sand as an explosive barrier material to design super-large explosion containment vessels is the most ideal. Therefore, it is essential to analyze the dynamic strain variation of the flat cover on the explosion containment vessel under different sand thicknesses by experimental method. First, by observing the history curves of strain collected by the experiments, it is found that the overall dynamic strain in 1000 ms consists of an abruptly rising phase and a gradually decreasing vibration recovery phase. By comparing the strain histories, it is found that when the sand thickness is 450 mm, the peak strains and the quasi-static residual strains of the 8 mm and 6 mm flat cover are weakened dramatically. Therefore, covering the cap with sand can significantly undermine the dynamic strain on the container closure. With the gradual increase of the sand thickness, the peak strain and the quasi-static residual strain of the flat cover show a linear decay law, and the slope of the linear decay is not affected by the thickness of the flat cover. Finally, according to the experiments and numerical analyses, the most effective range of sand/steel thickness ratio is determined to be 50–75, which can be accurately determined according to the actual working conditions. Sand can effectively absorb the transmitted energy of stress waves, and the sand/steel composite anti-explosion structure can effectively resist the impact of confined explosion.