圆柱形薄壁储罐对爆炸冲击波动力学响应的模拟分析

Simulation analysis of dynamic response of thin-wall cylindrical tank to shock wave

针对圆柱形薄壁储罐在爆炸冲击波载荷作用下的动力学响应进行了模拟分析。采用LS-DYNA软件模拟计算了50m3液化石油气储罐爆炸后冲击波云图以及空间点冲击波超压随时间的变化关系,并将计算结果加载到圆柱形薄壁储罐上。模拟计算结果表明,对于距离爆炸中心50m处的圆柱形薄壁储罐,面向冲击载荷的底面在冲击波超压峰值还没有来临时就已经屈服,而背向冲击载荷的顶面在0.112ms时,等效应力达到屈服界限。而迎向冲击面的顶端结构在峰值载荷冲击后不久出现屈曲,结构在峰值位移10mm时出现部分卸载,变得不再稳定。因此,当罐区发生爆炸时,圆柱形薄壁储罐极有可能出现结构强度失效和结构失稳,会在冲击波的作用下失效,是不可靠的。

Simulation analysis of dynamic response of thin-wall cylindrical tank to shock wave was made. The software LS-DYNA was used to calculate the contour of pressure and the relationship between overpressure and time resulting from explosion of a tank filled with 50 m3 liquefied petroleum gas. The result was loaded to the thin-wall cylindrical tank located 50 m away. The simulation results indicated that the material located at the bottom of the thin-wall cylindrical tank facing the shock wave yielded before the peak of shock wave overpressure arrived, and the material located at the top of the thin-wall cylindrical tank back from the shock wave reached the yield point at 0. 112 ms after the explosion. The top of the thinwall cylindrical tank facing the shock wave appeared inflection soon after the peak of overpressure arrived. The top of the thin-wall cylindrical tank facing the shock wave began to unload when the transverse displacement reached 10 mm, and the tank became unstable. So, when there is an explosion in the tank area, the thin-wall cylindrical tank is very likely to become structurally unstable and lose structural strength, and it can be disabled under the effect of shock wave, so the thin-wall cylindrical tank is not reliable.