爆炸冲击作用下H型钢柱损伤等级快速评估

Method for Classifying Damage Level of Steel Column Under Impact of Explosion

随着燃油气的广泛使用,爆炸事件屡有发生,对建筑结构安全产生了巨大威胁。我国现行的爆炸灾损结构安全性鉴定方法以剩余承载力为指标确定其损伤等级,实际可操作性不强。针对这一问题,以《热轧H型钢和剖分T型钢》中常用规格H型钢为研究对象,应用有限元程序LS-DYNA,建立钢结构爆炸损伤分析的有限元模型,分析了钢柱水平位移及剩余承载力。通过引入剩余承载力系数K与相对挠度ωR的概念,基于数值模拟结果研究了H型钢柱在爆炸荷载作用下的剩余承载力系数K与相对挠度ωR的关系,据此提出了钢柱受损的判定依据并划分了损伤性等级。相较现有钢柱损伤等级划分方法更具可操作性。

The widespread use of fuel gas has posed great threats to the security of building structure,on account of the frequent explosion events.Nevertheless,the present method of damage level identification used for explosion damage structure in China is not practical,as it determines the damage level by the residual bearing capacity.In this paper,a finite element model of steel structure is established and the horizontal displacement and residual bearing capacity of steel column are analyzed.The analysis uses the finite element program LS-DYNA to investigate hot rolled H and cut T section steels following GB/T 11263-2017.The concepts of safety factor K and relative deflectionωRare introduced,and their relationships for H-shaped steel columns under explosive loading are analyzed through numerical simulation.Based on this,the criterion for determining the damage of steel column is proposed,together with the damage levels.Compared with the existing classification,the current method of steel column safety grade has a strong operability in practice.