不同瓦斯爆炸强度作用下管道壁面冲击破坏特征数值模拟

Abstract

为了获取管道壁面在瓦斯爆炸冲击作用下的破坏特性，利用LS-DYNA建立了管道内瓦斯爆炸物理模型和数学模型，模拟了管道内不同爆炸强度的瓦斯爆炸冲击破坏特性，模拟结果表明：在瓦斯爆炸瞬间，爆炸冲击波直接加载在管道壁面及封闭端，封闭端隅角处冲击波汇聚叠加，致使管道封闭端发生膨胀变形。随着瓦斯爆炸的进行，封闭端区域内出现了负压区，空气回流压缩，冲击波都汇聚在“Z”型槽里，此时管道壁面变薄，出现了“阶梯式”破坏特征。随着瓦斯爆炸强度的增加，爆炸冲击波荷载超过了材料的屈服强度，管道封闭端与内壁面结合隅角部位，内壁面沿管道出现了“Z”型破坏。随着爆炸荷载的持续加载，壁面最终出现了“阶梯式”的破坏和张开型的扩展现象。 In order to obtain the failure characteristics of the pipe surface under the shock wave action of gas explosion, the physical model and mathematical model of gas explosion in pipe are established by LS-DYNA, and the shock failure characteristics of gas explosion under different explosion strengths in pipe are simulated. The result shows that at the instant of gas explosion, the shock wave is directly loaded on the surface and the closed end of the pipe, and the shock waves at the corner of closed end are converged and superposed, which cause expansion and deformation at the closed end of pipe. With the continuation of gas explosion, the negative pressure zone is appeared in the closed end and the air reflux is compressed; the shock waves are converged in the “Z type” groove; at this time, the pipe surface becomes thin, and the “ladder type” failure characteristics appear on this surface. With the increase of the gas explosion strength, when the shock wave load exceeds the yield strength of the pipe, the “Z type” failure appears on the inner surface of the closed end of the pipe. With the sustained loading of gas explosion loads, the failure of the “ladder type” and the expansion phenomenon of “open type” appear at the pipe surface.