爆炸荷载作用下钢管混凝土柱的有限元分析

Finite element analysis for CFST columns under blast load

对于重要的建筑物和防护结构,通常都要考虑爆炸冲击荷载的作用,目前钢管混凝土已被广泛地应用于工程结构中。为研究爆炸荷载作用下钢管混凝土柱的力学性能,采用非线性有限元软件ANSYS/LS-DYAN对方钢管混凝土柱在表面爆炸荷载作用下的反应进行了数值模拟。混凝土采用H JC模型,钢管采用考虑应变率的随动硬化塑性模型。分析了折合距离为1.0时柱子的破坏形态和不同折合距离时关键点的位移反应。研究表明,折合距离为1.0时,尽管内填混凝土破坏严重,但钢管能约束混凝土的横向变形,表现出良好的延性,抗爆性能优越。且随着折合距离的增大,柱子变形明显减小。

The impact of blast load is always taken into consideration in significant building and protective construction. Presently, concrete filled steel tubular （CFST） is widely used in construction because it has the beneficial qualities of both concrete and steel. In order to study the mechanical behavior of the CFST column under blast load the dynamic responses of a square CFST column under surface explosion were simulated by the nonlinear finite element program ANSYS/LS-DYNA. The JHC model was used for concrete material and the MAT.PLASTIC.KINEMATIC model which accounted for the strain rate used for steel. The failure behavior of the CFST column at scale distance equal to 1.0 was analyzed. The results indicate that the inner concrete was seriously damaged, while the deformation of concrete was restricted by the steel tube. It shows that CFST column has excellent ductility and blast resistance. The time-history curve of displacement of key nodes at different scale distance were compared, which indicates that the deformation of the column obviously decreases with the increase of scale distance.