汽车炸弹钢箱梁内部爆炸局部破坏效应分析

采用ALE多物质流固耦合算法，对汽车炸弹 (TNT当量200kg~1500kg) 在双层桥梁下层桥面典型位置爆炸的局部破坏效应进行了数值模拟，研究了内爆炸冲击作用下钢箱梁的响应过程、破坏模式、破坏参数及其主要影响因素。结果表明：破坏模式及破坏参数与爆炸位置和TNT当量密切相关，爆炸位置对桥梁主要受力体系的受损程度影响较为明显，加劲肋对其垂直方向的破口具有约束作用，箱体对冲击波的约束效应使破坏作用加剧。合理设置加劲肋、加强重要构件和设置防爆层等措施有利于提高桥梁结构抗爆能力。

Analysis on the Local Damage of A Steel Box Girder under Internal Blast Loading of Vehicle Bomb

The response process, failure modes and damage parameters of a double deck steel box girder subjected to internal blast loading of vehicle bombs (TNT equivalent 200kg~1500kg) were simulated with the Fluid-Solid coupling arithmetic method of ALE Multi-material formulations, in which three typical blast locations on the lower deck were considered. The results show that: the failure modes and damage parameters have a clear correlation with the TNT weight and blast location, and the explosion locations have strong effects on the damage degree of the steel truss. Stiffening ribs can restrict the crack in its vertical direction. The damage effects have been intensified by the restriction of the box-shaped girder. Some useful measurements are also proposed which can help engineers for bridge designing and protection consideration against possible explosion events.