典型密闭装置内爆炸尺寸效应研究

为研究密闭装置内爆炸冲击波的传播规律及密闭装置尺寸效应对冲击波超压空间分布和爆炸荷载特征参数的影响,在混凝土密闭装置内爆炸试验的基础上,结合LS—DYNA有限元程序对不同尺寸的装置内爆炸进行数值模拟。结果表明:密闭装置内爆炸超压时程曲线大多呈现多峰特性,装置顶角、棱线附近超压曲线的周期宏观脉动现象比较明显,超压衰减缓慢;当结构长宽比例1.2≤LW≤3时,结构对冲击波的约束不是很明显,冲击波超压空间分布比较有规律;而当LW3时,结构对冲击波的约束表现得异常明显,冲击波超压空间分布规律不显著。对于5种不同尺寸的装置内爆炸,当比例距离2.134 m/kg1/3≤r珋≤3.201 m/kg1/3时,冲击波流场异常复杂且超压曲线多峰特性开始凸显,不能用简单的数学关系来描述冲击波的空间分布。

Effect of Scales on Typical Closed Structure Due to Internal Explosion

To study the propagation law of shockwave and the effect of scale effects of closed structure on the distri- bution of shockwave and characteristic parameters of blasting loading due to internal explosion, internal explosion experi- ment in the reinforced concrete is carried out in this issue. Based on the experiment, explosion in the closed structure with five types of different scales is simulated with LS-DYNA software. The results indicate that overpressure histories obtained by experiment and simulation both have many peaks ; and the periodically macro fluctuation of overpressure histories are ev- idently at the corner and across of two walls in the structure. The shockwave in the closed structure is of a slower attenua- tion. Shockwave distribution in the space is regular when the ratio of length and width （L ： W） of the structure is between 1.2 and 3. When L ： W 〉 3, shockwave is confined evidently and distributed erratically. For the explosion inside the struc- ture with five types of different scales, the shockwave is complex and the overpressure histories start to have many peaks when the scaled distance is 2. 134m/kg1/3 ≤r≤3. 201m/kg1/3, the distribution of shockwave can not be expressed mathe- matically.