方钢管螺旋箍筋混凝土柱轴压承载力及抗爆性能研究

发布时间：2019-02-23 19:02

【摘要】：近年来频发的爆炸事件给周边的工业民用建筑造成了极大的破坏。方钢管螺旋箍筋混凝土柱是方钢管混凝土柱内部增设连续螺旋箍筋所形成的新型组合结构柱,具有承载力高、延性好、便于梁柱连接、抗火能力强等优点,是工业民用建筑抗爆设计的理想结构形式。目前国内外针对方钢管螺旋箍筋混凝土柱的研究主要集中在轴压承载力方面,已有研究成果多是根据试验或数值模拟的结果进行回归分析得到的经验公式,理论依据不是很充分。此外,鲜有方钢管螺旋箍筋混凝土柱在爆炸冲击等动荷载作用下性能的研究报道。本文以方钢管螺旋箍筋混凝土柱为研究对象,针对其轴压承载力和爆炸荷载作用下的动力响应问题展开研究,主要内容如下:(1)基于统一强度理论分析了方钢管螺旋箍筋混凝土轴压短柱的极限承载力。根据约束力构成不同划分了混凝土截面,综合考虑了方钢管和螺旋箍筋的约束。利用面积等效将方钢管转化为圆钢管,在统一强度理论厚壁圆筒塑性极限荷载统一解的基础上,推导了方钢管螺旋箍筋混凝土轴压短柱的极限承载力公式。并对公式进行退化,扩展了其适用范围。最后进行了参数分析。(2)给出爆炸荷载作用下方钢管螺旋箍筋混凝土柱最大动位移理论解。基于钢管混凝土统一理论,将组成方钢管螺旋箍筋混凝土柱的方钢管、螺旋箍筋、混凝土视为统一的组合材料,给出了构件的塑性极限弯矩。将方钢管螺旋箍筋混凝土柱简化为等效单自由度体系,将爆炸荷载等效为下降三角形荷载,充分考虑了高应变率下材料性能的提升,得到柱中部最大动位移理论解。(3)进行了爆炸荷载作用下方钢管螺旋箍筋混凝土柱动力响应的数值模拟。采用Hypermesh建立了有限元模型,并通过设置应力初始化考虑了轴压作用的影响,利用LSDYNA Solver进行显式动力学分析。对轴压柱遭受爆炸冲击时的破坏模式、位移、应力、应变进行了分析。采用单一变量法对轴压比、材料强度、螺旋箍筋直径与间距、比例距离等影响因素逐一进行了分析,得到了影响规律并提出了设计建议。
[Abstract]:The frequent explosion in recent years has caused great damage to the surrounding industrial civil buildings. The square steel pipe spiral stirrups concrete column is a new type of composite structural column formed by adding continuous spiral stirrups inside the square steel tube concrete column. It has the advantages of high bearing capacity, good ductility, easy connection with Liang Zhu, strong fire resistance, etc. It is the ideal structure form of industrial civil building anti-explosion design. At present, the research on concrete columns with spiral stirrups of square steel tubes is mainly focused on axial bearing capacity at home and abroad. The existing research results are mostly empirical formulas obtained by regression analysis based on the results of test or numerical simulation. The theoretical basis is not very strong. In addition, there are few research reports on the behavior of concrete columns with spiral stirrups of square steel tubes under the action of explosive shock and other dynamic loads. In this paper, the dynamic response of concrete columns with spiral stirrups of square steel tubes under axial compression and explosive loads is studied. The main contents are as follows: (1) based on the unified strength theory, the ultimate bearing capacity of concrete columns with spiral stirrups is analyzed. The concrete section is divided according to the binding force composition, and the constraints of square steel pipe and spiral stirrups are considered synthetically. The square steel tube is transformed into circular steel tube by using area equivalent. On the basis of unified strength theory and unified solution of plastic limit load of thick-walled cylinder, the ultimate bearing capacity formula of spiral stirrups reinforced concrete short column of square steel tube is derived. The formula is degenerated and its scope of application is extended. Finally, the parameter analysis is carried out. (2) the theoretical solution of the maximum dynamic displacement of concrete column with spiral stirrups under explosive load is given. Based on the unified theory of concrete-filled steel tube (CFST), the square steel tube, spiral stirrups and concrete are regarded as the unified composite materials, and the plastic ultimate bending moment of the members is given. The concrete column with spiral stirrups of square steel tube is simplified as an equivalent single-degree-of-freedom system, and the explosive load is equivalent to a descending triangular load, and the improvement of material performance at high strain rate is fully considered. The theoretical solution of the maximum dynamic displacement in the middle of the column is obtained. (3) the numerical simulation of the dynamic response of the concrete column with spiral stirrups under explosive loading is carried out. The finite element model is established by Hypermesh, and the effect of axial compression is considered by setting stress initialization. The explicit dynamic analysis is carried out by LSDYNA Solver. The failure mode, displacement, stress and strain of axial columns subjected to explosion are analyzed. The influence factors such as axial compression ratio, material strength, diameter and spacing of spiral stirrups, and proportional distance are analyzed one by single variable method.
【学位授予单位】：长安大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TU398.9;TU352.13

【参考文献】