随着世界范围内的爆炸事件频繁发生，致使建筑结构受到爆炸冲击荷载发生严重破坏，同时引起的人员伤亡与财产损失不可估量，因此针对建筑物的抗爆性能研究成为目前结构工程领域的研究热点问题。钢管混凝土柱具有承载高、刚度大、延性好、施工便捷等诸多优点而广泛应用于高层建筑、大跨桥梁、地铁站等工程中作为主要受力构件之一。因此研究钢管混凝土柱在爆炸荷载作用下的动力特征，进而提出该组合柱的抗爆设计建议，具有重要的理论意义和工程应用价值。本文采用试验研究、理论分析和数值模拟相结合的方法对爆炸荷载下钢管混凝土柱的动态响应进行系统研究，主要的研究工作和创新成果包括以下几个方面： (1)研究了各种固体材料应变率相关模型的优缺点，根据钢管混凝土柱的受力特征，得到了钢管混凝土柱内核心混凝土在三向受力状态下的弹塑性本构关系，考虑了应变率影响，确定出各种模型的最优参数；对比分析了不同类型爆炸荷载的影响作用，结合本文试验研究确定了合理的爆炸荷载模型，建议采用TM5-1300中的特征参数进行后续参数扩展分析。 (2)基于相似原理和爆炸基本理论，设计了钢管混凝土柱在爆炸荷载作用下的试验方案，进行了钢管混凝土柱在3㎏TNT和50㎏TNT作用下的静爆试验研究，测量了钢管混凝土柱迎爆面与背爆面的超压时程曲线、加速度时程曲线，得到了钢管混凝土柱在真实爆炸荷载作用下的宏观变形及破坏特征。结果表明，对于刚度较大的结构构件来说，受迎爆面负压区、背爆面的影响很小，可以忽略不计，仅考虑迎爆面的正压区作用效应；当比例距离为0.19m/㎏〓时，伴随着柱脚焊缝被剪裂，钢管混凝土柱的破坏模态为整体弯曲。 (3)采用等效单自由度体系模型和理想塑性梁的动力分析两种方法，分别研究了钢管混凝土柱在爆炸作用下的动力响应，得到了弹性振动时的位移放大系数，弹塑振动时采用延性系数推导出等效体系的最大动位移，并将所得结果与试验结果进行对比，验证了等效单自由度体系理论计算的合理性和正确性。在忽略轴力的影响下，将爆炸冲击荷载作用下的钢管混凝土柱近似简化为理想弹塑性梁受冲击荷载作用的工况，研究了弹性振动、弹塑性振动的动力特征，为今后此类问题的理论分析研究提供可靠依据。 (4)基于有限元软件ANSYS/LS-DYNA，考虑了应变率效应对材料性能的影响、爆炸荷载不均匀性的流固耦合、爆炸波及其与钢管混凝土柱相互作用；在网格划分方面，以APDL实现了完全六面体网格划分，并研究了网格的均匀性和正交性对其计算结果的影响；通过考虑以上因素，建立了钢管混凝土柱在爆炸荷载作用下的非线性有限元模型，并将数值模拟结果与试验结果进行对比，吻合良好，从而验证了本文有限元建模方法的正确性和模型的合理性。基于合理的有限元数值模型，进行了钢管混凝土柱在爆炸荷载作用下的参数分析，研究了比例距离、加载速率、截面形状及尺寸、材料强度等因素对钢管混凝柱动态响应的影响。结果表明，提高混凝土和钢材的强度、增大含钢率，均能在一定程度上提高钢管混凝土柱的抗爆性能；对比了方形截面柱与圆形截面柱的计算结果，发现后者具有较强的抵御爆炸荷载能力。 本文针对钢管混凝土柱在爆炸荷载作用下的动态响应进行了试验研究、理论分析和有限元数值模拟，得到了一系列具有创新性的研究结论，为钢管混凝土柱的工程应用和抗爆设计提供理论依据，具有重要的社会意义。 ①本论文得到以下项目的资助：国家自然科学基金项目(51878056，51508028)，高等学校博士学科点专项科研基金资助(20110205130001)。 关键词：钢管混凝土柱，爆炸冲击荷载，试验研究，等效单自由度，弹塑性动力响应，数值模拟

 With the frequent occurrence of explosion events all over the world,the building structure is severely damaged caused by the blast impact loads, and in the meanwhile, the casualties and economic losses are inestimable. Therefore, the study on the anti-explosion performance of buildings has become a hot topic in the field of structural engineering. Concrete-filled steel tubular columns are widely used in high-rise buildings, large span bridges, subway stations and other engineering projects as one of the main load-bearing components due to their high strength and stiffness, good ductility and can be constructed easily. Therefore, it is of great theoretical significance and engineering application value to study the dynamic characteristics of concrete-filled steel tubular column under the action of explosion load and to propose the anti-explosion design suggestions of the composite column. In this paper,the dynamic response of concrete-filled steel tubular column under explosive load is systematically studied by combining experimental research,theoretical analysis and numerical simulation. The main research works and innovative achievements include the following aspects: (1)The advantages and disadvantages of strain rate models of various solid materials were studied. According to the stress characteristics of concrete-filled steel tubular column, the elastic and plastic constitutive relations of the core concrete in the concrete-filled steel tubular column under three-direction stress condition were obtained. The effects of different types of explosion loads were compared and analyzed. A reasonable explosion load model was determined by combining with the experimental study of this paper. It is suggested to use the characteristic parameters in TM5-1300 for subsequent parameter expansion analysis. (2)Based on the similarity principle and the basic theory of explosion, blast tests on the concrete filled steel tubular columns were designed with 3㎏ TNT and 50㎏ TNT. The concrete-filled steel tube column face blasting face and back on the surface of the explosion overpressure time history curve and the acceleration time history curve of the concrete filled steel tubular column under real explosion load were measured. The macroscopic deformation and destruction features of the test specimens were obtained. The results show that for the structural members with large stiffness, the negative pressure area of the blasting surface and the back detonation surface have little influence and can be neglected. When the proportional distance is 0.19m/㎏〓, the failure mode of the concrete-filled steel tube column is overall bending with the shear cracks observed on the welds of the column foot. (3)By using the equivalent single degree of freedom system model and two methods of dynamic analysis of the ideal plastic beam, the dynamic response of a steel tube concrete column under the effect of explosion were obtained respectively. The displacement magnification coefficient of elastic vibration was also obtained. The maximum dynamic displacement ductility coefficient of equivalent system is deduced when the elastic-plastic vibration was used,and the rationality of the theoretical calculation of the equivalent single degree of freedom system was verified by the test results. When the influence of axial force was ignored, the concrete-filled steel tube column under the blast impact load was simplified to the ideal elastic plastic beam under the impact load,and the dynamic characteristics of elastic vibration and elastic-plastic vibration were studied, which provided a reliable basis for the theoretical analysis and research of this kind of problem in the future. (4)Based on finite element software ANSYS/LS-DYNA, the nonlinear finite element model of the concrete filled steel tubular column under explosion load was established with considering the effect of strain rate on material properties, the blast load uniformity of fluid-structure interaction, explosion wave and its interaction with concrete filled steel tubular column, the servo model of steel and the HJC model of the core concrete,the agreement between the results of numerical simulation and the experimental results was good,which verified the validity and rationality of the modeling method in this paper. Based on the reasonable finite element numerical model, the parameter analyses of the concrete-filled steel tubular column under the action of explosion load were performed, and the effects of the proportional distance, the loading rate,the section shape and section size,the compressive strength of concrete, the yield strength of steel and steel ratio on the dynamic response of concrete-filled steel tubular concrete column were studied. The results show that the anti-explosion performance of concrete-filled steel tubular column can be improved in a certain margin by improving the strength of concrete and steel and increasing the steel ratio. It is found that the circular column has better performance to resist the explosion load by comparing with the performance of the square column. In this paper, among experimental research, theoretical analysis and finite element numerical simulation were carried out for the dynamic response of concrete-filled steel tubular column under the action of explosion load, and a series of innovative research conclusions are obtained, which provide theoretical basis for the engineering application and anti-explosion design of concrete-filled steel tubular column, and have important social significance. ①This dissertation is supported by the National Natural Science Foundation (Grants No. 51878056 and 51508028),and the Special Research Foundation of Higher Education Doctoral Program (Grants No. 20110205130001). Keywords: concrete-filled steel tubular (CFST) column, blast load,experimental research, equivalent single-degree-of-freedom (SDOF) system, dynamic response of elastic-plastic, numerical simulation