储罐外爆冲击波数值模拟及超压公式研究

Research on propagation rule and overpressure formula of blast shock wave outside storage tank

为研究储罐外爆冲击波的传播规律和对储罐安全性的影响,应用软件LS-DYNA建立炸药-储罐的数值模型,并进行空爆数值计算。研究分析储罐外爆冲击波超压的衰减关系和罐体的动力响应,与经验公式的对比验证了模型的可信性,并结合经验公式平均值对数值模拟结果做了进一步修正。结果表明:冲击波运动到迎爆面中心后,外罐主应力在10 ms时迅速达到最大值,随后主应力值迅速减小,并不断振荡;迎爆面中心首先产生较大的拉应力,混凝土外罐的破坏属于脆性破坏;比例距离大于1时,现有超压计算公式拟合超压的衰减规律误差较小,比例距离小于1时,超压计算公式误差较大,修正后的超压计算公式可为储罐抗爆设计提供参考。

To study the propagation rule of blast shock wave outside tank and its impact on the safety of storage tank,the software LS- DYNA was used to build numerical model of dynamite- storage tank,and the air blast numerical calculation was performed. The study analyzed the attenuation relation of shock wave overpressure and the dynamic response of the tank. The reliability of the model was verified by contrast with the empirical formula. And the further amendment for numerical simulation results was made. The results are as follows： When shock wave moves to burst surface center,principal stress in 10 ms quickly reaches maximum value,and then decreases rapidly and continuously oscillated; The facing blasting center first produces larger tensile stress,the destruction of concrete tank belongs to brittle failure; When the proportion distance is greater than 1,overpressure formula can better fit the attenuation law of overpressure; While the proportion distance is less than 1,the error of the overpressure formula is large. The amended overpressure calculation formula can be used as a reference tank blast- resistant design.