配加劲件钢管混凝土抗弯抗拉及复杂应力下统一理论研究

发布时间：2018-03-05 16:22

本文选题：内配加劲件的钢管混凝土　切入点：抗弯承载力　出处：《哈尔滨工业大学》2015年硕士论文　论文类型：学位论文

【摘要】：内配加劲件的钢管混凝土不仅具有承载力高、刚度大、延性好等特点,又可克服普通钢管混凝土壁厚过厚、抗火性能差等缺点,已经逐渐在工程中开始运用。而其作为一种新型复合构件,工作机理较为复杂,力学性能、连接构造等都没有展开系统的研究。本文以内配钢管、内配钢筋和内配型钢的钢管混凝土作为研究对象,对抗弯承载力、复杂应力下的相关关系及其在抗拉作用下内外钢构件共同工作的性能进行了探讨,以期取得形式简洁且取值科学的承载力设计值。研究极限状态下的抗弯承载力。本文通过求解纯弯作用下构件达到极限状态的平衡方程,讨论中性轴的位置情况,将中性轴位置代入弯矩平衡方程,取得了内配加劲件钢管混凝土的极限抗弯承载力理论值。同时利用有限元软件ABAQUS建立纯弯作用下的抗弯模型,验证理论解的准确性。并将理论值、有限元值对协会标准提出的特殊钢管混凝土抗弯承载力规范值进行校验和修正。后通过3组18根内配加劲件钢管混凝土纯弯试验对校验修正后的规范值进行验证。研究复杂应力下的相关方程。基于极限平衡理论,将内配加劲件的钢管混凝土看作外钢管、内钢管、混凝土三种元件构成的结构,先不考虑三者的相互作用,求解压、弯、剪、扭作用下的平衡方程,将内配加劲构件的钢管混凝土模型等效为一个由等效压杆、混凝土斜腹杆和钢材拉杆组成的空间桁架模型,消去内力项,验证内配加劲件钢管混凝土的相关方程的理论形式。后通过有限元模拟,校验规范给出的相关方程。研究内外构件非均匀全截面受拉时的共同工作性能。首先进行受拉和受压情况下内外钢管粘结试验,得到极限粘结应力及其影响因素,明确破坏机理和过程;根据已有的钢筋和型钢与混凝土之间的粘结力理论,考虑内部加劲件和混凝土之间的粘结作用,初步得到非均匀全截面受拉承载力设计值;进而初步设计内配加劲件的格构式钢管混凝土塔架试验和内外钢构件的连接方式,并对试验进行有限元模拟,分析和比较内配筋和内配型钢方案共同工作能力的差异。
[Abstract]:The concrete-filled steel tube (CFST) with internal stiffener not only has the characteristics of high bearing capacity, high stiffness and good ductility, but also can overcome the shortcomings of ordinary concrete-filled steel tube (CFST), such as overthick wall thickness, poor fire resistance and so on. It has been gradually used in engineering. As a new type of composite component, its working mechanism is more complex, mechanical properties, connection structure and so on have not been systematically studied. Concrete filled steel tube (CFST) with internal steel bar and steel section is the object of study. The relationship between bending bearing capacity and complex stress, and the performance of internal and external steel members working together under the action of tension are discussed. In order to obtain the design value of bearing capacity with simple form and scientific value, the bending bearing capacity under the limit state is studied. In this paper, the position of neutral axis is discussed by solving the equilibrium equation of the ultimate state of the member under pure bending. The position of neutral axis is substituted into the moment equilibrium equation, and the theoretical value of ultimate flexural bearing capacity of concrete-filled steel tube with internal stiffener is obtained. At the same time, the bending model under pure bending is established by using the finite element software ABAQUS. Verify the accuracy of the theoretical solution. The finite element value is used to check and revise the concrete filled steel tube concrete filled steel tube (CFST) flexural bearing capacity, which is put forward by the association standard, and the revised code value is verified by 3 groups of 18 concrete filled steel tube concrete filled steel tube pure bending tests. To study the equation of complex stress, based on the limit equilibrium theory, The concrete-filled steel tube with internal stiffener is regarded as a structure composed of three kinds of elements: outer steel tube, inner steel tube and concrete, and the equilibrium equation under the action of compression, bending, shear and torsion is obtained without considering the interaction of the three elements. The concrete filled steel tube model with internal stiffening members is equivalent to a space truss model composed of equivalent compression bar, concrete inclined web bar and steel tension bar, and the internal force term is eliminated. To verify the theoretical form of the relevant equations of concrete-filled steel tube with internal stiffener. The relevant equations given in the calibration code. The common working performance of the non-uniform full section of internal and external members under tension is studied. First, the bonding tests of internal and external steel tubes under tension and compression are carried out, and the ultimate bond stress and its influencing factors are obtained. According to the existing theory of bond force between steel bar and section steel and concrete, considering the bond effect between internal stiffener and concrete, the design value of tensile bearing capacity of non-uniform full section is obtained preliminarily. Furthermore, the test of concrete filled steel tubular tower with internal stiffener and the connection mode of internal and external steel members are preliminarily designed, and the finite element simulation of the test is carried out, and the difference of the common working ability between the internal reinforcement and the inner section steel is analyzed and compared.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU398.9

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