密闭空间内爆炸载荷抑制效应实验研究

炸药在密闭空间内爆炸时的爆炸载荷与在敞开环境中有很大差异,在密闭空间内,TNT炸药的爆炸产物能够与周围空气充分混合并发生燃烧反应进而释放额外的能量,使密闭空间内的反射冲击波及准静态压力均明显增加。为探究不同气体环境对密闭空间内爆炸载荷的抑制效应,开展了3种不同药量的TNT分别在空气、水雾和氮气环境密闭空间内的爆炸实验研究,通过理论计算和实验对比分析了密闭空间内的爆炸载荷压力、温度及受载钢板试件响应特性。结果表明,水雾和氮气均能有效降低空间内的准静态压力和温度,对准静态压力的平均降幅分别为36.0%和51.7%,对温度的平均降幅分别为42.6%和40.3%;在水雾和氮气环境中的爆炸载荷作用下,钢板试件动态响应较空气环境中显著降低,其中160 g药量下,水雾和氮气环境中钢板试件的最终变形分别减少了15.9%和23.5%,氮气的减弱效果优于水雾;水雾和氮气均能及时有效地抑制封闭空间内的爆炸载荷,降低结构的损伤程度。

Dynamic Behavior of a New Hydraulic Steel Gate

A new style of hydraulic steel gate based on the principle of bionics is proposed in this paper. It has a fish-like shape and consists of right arches, invert arches, connection components and a face plate. It would be first applied in the project of Caoe River Sluice, used as both tidal barrage and flood gate. Compared with conventional hydraulic steel gate of beam grids, this new style of hydraulic steel gate can save up to 30%-50% of steel consumption. The dynamic behavior of the new gate under the impact load of tidal bore is investigated. The impact load of tidal bore is considered by a load spectrum obtained by field observation over a long period of time. Then a numerical analysis of the gate under the load spectrum is carried out by finite element method. The fluid-structure interaction is considered in the analysis. And a comparison between the response of the gate under the impact load and the response of the gate under the corresponding static load is conducted and indicates that the gate has a dynamic magnification factor of 1.2.