近距离爆炸荷载作用下砌体墙动态响应及破坏过程的数值模拟
2016-03-03郭玉荣张楠
郭玉荣 张楠
摘要:为了探索砌体墙在近距离爆炸荷载作用下的破坏规律及碎块抛射规律,通过AUTODYN建立数值模型,得到在近距离手提箱包炸弹爆炸荷载作用下砌体墙的荷载分布规律及碎块抛射速度规律.结果表明:12墙、24墙、加固24墙在爆炸荷载作用下破坏规律是相似的.24墙及加固24墙相对12墙碎片抛射速度有较明显的降低.加固24墙由于聚氨酯加固膜的兜裹作用,最终会明显减小碎块的出墙面位移和速度.此外砌体墙各测点抛射速度与比例距离的关系曲线与超压峰值与比例距离关系比较相似.
关键词:砌体墙;动态响应;爆炸荷载;爆炸碎片;防爆
中图分类号:TU375 文献标识码:A
Abstract:In order to explore the failure process and fragments ejection rule of blast case for masonry walls, the AUTODYN program was used to simulate the dynamic response of masonry walls under close range blast load. The distribution of blast pressure on masonry walls and debris ejection laws were obtained. The results show that the destruction rules of 120 mm, 240 mm masonry walls, and the strengthened 240 mm wall under close range blast load are similar. The debris ejecting speed of 240 mm wall and the strengthened 240 mm wall declines obviously when compared with 120 mm masonry wall. The debris ejecting speed of the strengthened 240 mm wall declines significantly on account of the consolidated film of PU. Moreover, the relationship between ejecting speed and scaled distance is similar to the relationship between scaled distance and peak overpressure.
Key words:masonry walls; dynamic response; blast load; explosion fragments; explosion prevention
日益频繁的恐怖爆炸袭击活动,使工程师们不得不面对更加严峻的挑战:即如何保证结构在爆炸冲击荷载下的安全,以避免人员伤亡及财产损失.由于砌体墙的经济性,砌体墙几乎应用于所有的建筑结构中.然而在爆炸冲击荷载作用下,相对于钢筋混凝土结构砌体墙表现出很强的脆性[1],高速爆炸冲击波产生冲击荷载使砌体碎片以很高的速度抛射,给建筑的使用者造成严重的伤害.因此自9.11恐怖袭击事件以来,世界各国的政府和研究机构对砌体墙的抗爆问题进行了广泛而深入的研究.2002年,美国The Technical Support Working Group (TSWG),进行了一系列的砌体墙试验对超压-冲量破坏进行考察.此外他们对墙体的破坏形态做了分类,共4种[2]:“可使用”、“可修复”、“倒塌”和“碎片飞出”.当墙体出现碎片飞出的情……
