钢框架内爆炸连续倒塌简化分析方法

A SIMPLIFIED ANALYSIS METHOD ON PROGRESSIVE COLLAPSE OF STEEL-FRAME BUILDING UNDER INTERNAL EXPLOSION

目前我们对建筑结构进行连续性倒塌分析时经常参考和借鉴美国GSA规范方法,这种方法中的倒塌评判标准在我国不是很适用。爆炸激励仿真分析方法虽然可以考虑空气冲击波对结构的作用及结构构件的损伤破坏,但是由于计算量过大而很难在实际工程中应用。该文利用简化的爆炸荷载考虑爆炸空气冲击波对结构构件的作用;利用可以考虑应变率效应的非线性梁单元模拟结构构件;用删除失效单元的方法考虑结构构件失效;通过设置结构构件之间及其与地面之间的接触来考虑结构构件在倒塌过程中的相互作用及荷载的向下传递,从而发展了一种简化的爆炸荷载作用下结构连续倒塌分析方法。并通过与爆炸激励仿真分析方法计算对比发现,该文简化方法计算的结构倒塌过程真实合理,计算结果可靠,能反应出结构在内爆炸荷载作用下的响应,并且可以大大减少计算消耗。

At present, General Services Administration （GSA） standard method is widely used for reference to analyze progressive collapse of buildings. However, the criteria of collapse evaluation of this method are found inapplicable in China. Although the loading on structure caused by air shock wave and the damage failure of structural members are considered in explosive incentive simulation analysis method, it is hard to apply in practical engineering due to its computational complexity. In this paper, a simplified progressive collapse analysis under explosive loading is developed by utilizing the simplified explosive loading to take account of the impact on structure members caused by air shock wave, by applying nonlinear beam element taking account of strain rate effect to structural members, by adopting the method of killing failure element to take account of structural members failure, and by setting contact elements among structural members and contact elements between structural members and the ground surface to take account of the interaction and load transfer behavior of structural members in the process of progressive collapse. After comparing with the explosive incentive simulation analysis method, it is found that the simplified method proposed in this paper offers reasonable collapse process, reliable calculation results and response of structure under the impact of explosive loading, and it also greatly reduces computational requirements.