【作者】 刘新义；

【导师】 何明胜；

【作者基本信息】 石河子大学 ， 水工结构工程， 2007， 硕士

【摘要】 薄壁钢管轻质混凝土结构体系具有受力性能好、轻质高强、施工速度快等优点，与普通钢管混凝土相比还具有用钢量少的优势。因此，该结构体系具有很大发展前途，对其进行研究非常有意义。有关该组合结构的研究较少，尚未形成相关的规范或规程，进行该结构体系短柱轴压力学性能研究，对该结构体系的进一步研究是十分必要的。本文通过试验、有限元仿真及数值计算的方法对薄壁方钢管轻骨料混凝土短柱在轴心压力下的力学性能进行了研究，做了以下几点工作：(1)以本地生产的陶粒为轻粗骨料，以水灰比和砂率为影响因素，以轻骨料混凝土强度和容重为控制指标，设计了9组轻骨料混凝土的配合比试验，通过试验结果分析，提出了最优配合比。(2)介绍了以套箍系数ξ为控制因素的16根薄壁方钢管轻骨料混凝土短柱的轴压试验结果，对影响短柱承载能力及延性的因素进行了分析。(3)考虑冷弯效应、管壁的有效宽度，推导了核心混凝土强度提高系数K_C的表达式。对Popovics提出的单轴约束混凝土本构方程进行修正，获得了核心轻骨料混凝土的本构关系。通过数值计算，获得了薄壁方钢管轻骨料混凝土短柱的应力～应变曲线。给出的应力-应变全过程曲线，与试验结果比较吻合较好。在上述基础上提出了轴压承载力的简化计算方法，取得令人满意的计算结果。(4)以本文修正的组合构件本构关系为基础，对薄壁方钢管轻骨料混凝土短柱的轴压力学性能进行了非线形有限元分析。通过对模型高度中部截面钢和混凝土横向应变的描述与分析，得出薄壁方钢管混凝土中混凝土受钢管的侧向约束主要集中在角部。因此截面的四个角部承担了核心混凝土的大部分竖向应力和横向应力。更多还原

【Abstract】 There are many advantages to the lightweight aggregate concrete filled thin-walledsteel tube structural system (LACFTST), such as good mechanics performance,lightweight-high strength, short construction period, and so on. Besides, the consumable steelof this structural system is less than which of common concrete-filled steel tubes, so there isextensive development outlook of this structural system, and studying the structure system isvery significance. But the studies of the structure system is little, no code or specification hasbeen formed now, therefore, it is necessary to research to the mechanics performance of theshort columns under axial pressure. Mechanics analysis of lightweight aggregateconcrete-filled thin-walled steel box columns under axial pressure is carried out in this paperby experimental method, finite element emulation& numerical calculation, the main contentsare listed as follows:(1) Using ceramsite produced in this region as lightweight aggregate, nine groupLightweight Aggregate Concrete specimens with different mix ratios were designed in thispaper, here, the water-cement ratio& the sand ratio is affect factor and the strength oflightweight aggregate concrete& the intensity is the control objective. The optimum mix ratiois obtained through analysis of the test results.(2) Taking constrain effect factorξas control factor, The tested results of 16lightweight aggregate concrete-filled thin-walled steel box columns specimens under axialcompression is introduced. Factors influencing the bearing capacity and ductility have beenanalyzed, and the rule of them is generalized.(3) The reinforcing modulus Kc is derived considering the effect of the cold curved effectand the effective width. A mechanical model for the lightweight aggregate concrete filledthin-walled square steel tubular columns is proposed in the paper by amended the equationthat were established by Popovics. The stress-strain curve of the LACFTST is obtained bynumerical calculation. The theoretical results are in good agreement with that of the test. Asimplified method is also derived based on the model. Comparisons between the calculatedload of the simplified method and the experiment results show that the simplified method isreliable.(4) Non-linear finite element analysis of the LACFTST is carried in the paper on the baseof the amended equation that were established by Popovics. The constraint behavior of theLACFTST section is researched by analysis of the lateral deformation. The lateral deformation of the steel and concrete in the middle section is described and analyzed.Analyzed results show that the lateral constraint of the concrete in the LACFTST is mainly atthe corner. So the concrete in corner bear the majority vertical stress and lateral stress.更多还原