针对桥上爆炸作用下正交异性钢桥面板,开展了基于钢板爆炸试验验证的数值模拟研究.分析了美国联邦应急管理署(FEMA)规定的五种威胁类型爆炸作用下泰州长江大桥钢桥面板的破坏机理,揭示了桥面板不同构件的破坏模式.主要结论如下:(1)所有爆炸工况中,均观察到顶板花瓣状破口、U肋断裂及撕裂和横隔板塑性变形.对于较大炸药量工况(1 814 kg TNT、4 536 kg TNT和13 608 kg TNT),桥面板破坏模式还包括横隔板面外弯曲、局部屈曲和断裂、底板U肋断裂以及底板破口.(2)对于较小炸药量工况(227 kg TNT和454 kg TNT),桥面板主要耗能机制为顶板和顶板U肋耗能,总耗能占比超过70%;而较大炸药量工况桥面板主要耗能机制为顶板、顶板U肋、横隔板、底板和底板U肋共同耗能,总耗能占比超过90%.
Damage Mode of Orthotropic Steel Bridge Deck under Above-Deck Explosion
Concerning the orthotropic steel bridge decks under above-deck explosions,a numerical simulation study based on steel plate explosion tests was conducted.The damage mechanism of the steel bridge deck of Taizhou Yangtze River Bridge was analyzed under explosions of five threat types specified by the Federal Emergency Management Agency(FEMA),and the damage modes of different components of the bridge deck were revealed.The main conclusions are as follows.In all explosion scenarios,petal-shaped openings on the top plate,fracture and tearing of U-ribs,and plastic deformation of cross beams were observed.For scenarios with larger explosive charge(1 814 kg TNT,4 536 kg TNT,and 13 608 kg TNT),the failure modes of the bridge deck also include outward bending,local buckling,and fracture of cross beams,fracture of the U-ribs,and openings on the bottom plate.In scenarios with smaller explosive charge(227 kg TNT and 454 kg TNT),the main energy consumption mechanism of the bridge deck was the top plate and top plate U-ribs,accounting for over 70%of the total energy consumption.In scenarios with larger explosive charge,the main energy consumption mechanism of the bridge deck involved the top plate,top plate U-ribs,cross beams,bottom plate,and bottom plate U-ribs,accounting for over 90%of the total energy consumption.
万方数据
维普
