爆炸荷载作用下方钢管混凝土柱的动力响应及破坏机理  

Dynamic Response and Failure Mode Analysis of Concrete Infilled Rectangular Steel Tube Columns under Blasting Loading

作　　者：阎石[1,2] 刘蕾[1] 齐宝欣[1,3] 辛志强[1] 李鹏[1] 

机构地区：[1]沈阳建筑大学土木工程学院,沈阳110168 [2]北京理工大学爆炸科学与技术国家重点实验室,北京100081 [3]大连理工大学建设工程学部,辽宁大连116024

出　　处：《防灾减灾工程学报》2011年第5期477-482,共6页Journal of Disaster Prevention and Mitigation Engineering

基　　金：爆炸科学与技术国家重点实验室开放基金项目(KFJJ10-14M)资助

摘　　要：方钢管混凝土柱是被广泛采用的组合构件之一。爆炸发生时产生的爆炸冲击波可能会对框架结构内部的方钢管混凝土柱造成严重破坏,然而目前对其动力响应及破坏机理的研究成果相对较少。本文采用有限元分析软件ANSYS/LS-DYNA对爆炸荷载作用下方钢管混凝土柱的动力响应和破坏机理进行了研究分析。建立了方钢管混凝土柱实体有限元模型,其中混凝土采用HJC模型,方钢管采用考虑应变率的塑性随动强化模型,爆炸荷载施加在柱子一侧表面。通过对方钢管混凝土柱的破坏过程的模拟,比较分析了其在不同"比例距离"下的动力响应和破坏形式,进而得出方钢管混凝土柱的破坏机理。在爆炸荷载作用下,方钢管对其核心混凝土有一定的约束作用,使其处于复杂应力状态之下,从而使混凝土强度得以提高,塑性和韧性同时得到改善;同时,由于混凝土的存在,延缓了方钢管柱底和柱顶过早地发生局部屈曲。随着"比例距离"的增大,柱中水平位移逐渐减小。结果表明,方钢管混凝土柱具有良好的延性、优越的抗爆性能,所提出的破坏机理可供结构抗爆设计的进一步研究参考。The concrete infilled rectangular steel tube（CIRST） column is a kind of typical member used in light-weight steel frame structures.The explosion happening in the building due to the gas leaking may cause severe damage to the CIRST columns.However,less attention was paid to the enormous damage to the column under the blast loading.A typical CIRST column is numerically analyzed in the paper to investigate the dynamic responses and failure modes under the blast loading by using finite element software ANSYS/LS-DYNA.A solid model is made for the numerical analysis of the column.The MAT-PLASTIC-KINEMATIC model and the JHC model are used for the steel tube and the infilled concrete,respectively,to consider the strain rate effect.The blast loads are hypothetically applied to the surface of the column.The dynamic responses of the CIRST column are numerically analyzed and the attention is focused on the failure modes under different scaled distances of explosions.The numerical simulation shows that the failure mechanism of the CFRST column may be described as that the rectangular steel tube has a certain confined function for the infilled concrete to increase the strength of the concrete in complex stress state,and the ductility and toughness performance is also improved at the same time,resulting in delay of the early local buckling because of the existence of the concrete.As increasing of the scaled distances of the explosion,the horizontal displacement of the column at the middle span is also decreased.The results also show that the CIRST column has the excellent ductility and blast resistance.The failure mechanism and the numerical analysis method developed in the paper may provide a reference for the design of the structure under blast loading.

关 键 词：动力响应 破坏机理 方钢管混凝土柱 爆炸荷载 有限元分析 

分 类 号：TU352.1[建筑科学—结构工程]