爆炸冲击作用下储油罐毁伤特性的数值模拟

Research on damage characteristics of oil storage tank under the impact of explosion by numerical simulations

大型储油罐是石油库的主要设备,研究其在爆炸载荷下的动态破坏特性意义重大。为获得拱顶油罐结构在爆炸冲击作用下的毁伤机制,采用ANSYS/LS-DYNA建立了柴油拱顶油罐的有限元数值模型,开展了不同炸药量和储油量下拱顶油罐结构的爆炸冲击破坏过程的数值模拟研究。结果表明:储罐内部爆炸后会出现两个薄弱区域,分别出现在罐壁与拱顶的环向交接处和柴油液面的分界处;储罐爆炸冲击波的分布几乎不受TNT当量变化的影响,但爆炸超压随着TNT炸药质量的增加而显著增强;储罐内部的油料液体可以减弱爆炸冲击载荷对罐体结构的破坏效应。研究可为既有罐区安全功能改进和新罐区建设提供理论支撑。

Large oil storage tanks are necessary equipment in oil depots.To study the damage mechanism of the vaulted oil tank structure under the action of explosion impact,the finite element numerical model of the 37.04 m diesel vaulted oil tank was established by ANSYS/LS-DYNA software in this paper,and the numerical simulation study of the explosion impact failure process of the vaulted oil tank structure under dfferent explosives and oil storage capacity was carried out.The finite element model of the storage tank consists of four parts:the storage tank structural unit,the explosive unit,the air unit,and the diesel unit.Among them,explosive,diesel oil,and air were modeled by Euler grid,multi-substance ALE algorithm was used,and fluid-structure interaction was set.The tank shell was modeled by the Lagrange grid.Because the air domain outside the oil tank was infinite,non-reflection boundary conditions were set to simulate the real working conditions of the oil tank.The numerical simulation results show that:After the vaulted oil storage tank is impacted by the internal explosion,there are two relatively weak areas in the oil tank structure.The first one is the circumferential junction of the tank wall and the vault,the stress distribution on the interface changes,and there is an obvious stress concentration phenomenon;The second one is the boundary between the tank wall and the diesel liquid level,the extrusion force of the liquid interacts with the vertical tensile stress of the tank wall,and the tank wall structure is easily damaged.After the structure of the storage tank is subjected to the explosion shock,the damage positions are relatively similar,and the damaging effect increases significantly,indicating that the distribution of the explosion shock wave is hardly affected by the change of the TNT equivalent.But the explosion overpressure increases significantly with the increase of the TNT explosive mass.By comparing and analyzing the displacement of the tank wall under different oil storage volumes,the structural damage effect of the oil tank in the full oil state is weaker than that of the bottom oil.