钢—混凝土组合梁耐久性试验研究及时变可靠性分析

发布时间：2018-05-02 23:20

本文选题：钢-混凝土组合梁 + 耐久性　；参考：《中南大学》2014年硕士论文

【摘要】：摘要：钢-混凝土组合结构由于兼有钢结构和混凝土结构的优点,极具应用前景。然而,由于长期以来我国在结构设计中对耐久性问题重视不够,对钢-混凝土组合结构的耐久性损伤更是认识不足,可能使得结构在使用一段时间后出现耐久性危机。本文针对我国钢-混凝土组合梁耐久性研究中存在的问题,利用人工气候加速锈蚀方法,分析了腐蚀后钢-混凝土组合梁的力学性能退化规律,并对其时变可靠性及耐久性寿命进行了分析。主要研究内容如下： (1)利用干湿循环加速锈蚀试验,研究了锈蚀后栓钉剪力连接件的力学性能退化规律,建立了锈后栓钉强度退化模型及其本构关系模型,并对栓钉抗剪承载力设计值计算公式进行修正；在已有研究成果的基础上,对型钢的锈蚀分布规律、锈蚀深度发展规律及锈蚀后力学性能进行了分析,为钢-混凝土组合梁耐久性的研究提供依据。 (2)利用干湿循环加速锈蚀试验,研究了栓钉锈蚀后推出试件的力学性能变化规律,对推出试件的破坏形态、极限承载力、滑移值、刚度及延性的变化规律进行了分析。 (3)利用干湿循环加速锈蚀试验,研究了腐蚀后钢-混凝土组合梁的力学性能变化规律,对其截面应变、极限滑移、刚度及延性的变化规律进行了分析,引入部分抗剪连接组合梁抗剪连接度降低系数k(ρ),建立栓钉锈蚀后部分抗剪连接组合梁的极限抗弯承载力计算公式,并对比了试验值与理论计算结果,验证了该公式的实用性。 (4)考虑钢梁锈蚀、混凝土性能劣化以及栓钉锈蚀引起的组合梁抗剪连接程度的降低,建立了组合梁的抗力时变模型,提出了钢-混凝土组合梁的时变可靠性及耐久性寿命分析方法,并以一座公路简支钢-混凝土组合梁为例,给出了可靠性分析的具体过程,计算了该结构的时变可靠指标及耐久性使用寿命,并对其可靠性的影响因素进行了分析。
[Abstract]:Abstract: steel-concrete composite structure has great application prospect because of its advantages of both steel structure and concrete structure. However, due to the lack of attention to durability in structural design in China for a long time, the durability damage of steel-concrete composite structures is even less understood, which may lead to durability crisis after a period of time. Aiming at the problems existing in the durability study of steel-concrete composite beams in China, the degradation law of mechanical properties of steel-concrete composite beams after corrosion is analyzed by means of accelerated corrosion method in artificial climate. The time-varying reliability and durability life are analyzed. The main contents of the study are as follows: 1) the degradation law of mechanical properties of the corroded bolt shear joint was studied by the accelerated corrosion test of dry and wet cycles, and the strength degradation model and the constitutive relation model of the post-rust bolt were established. On the basis of the existing research results, the corrosion distribution law, corrosion depth development law and mechanical properties after corrosion of section steel are analyzed. It provides a basis for the study of durability of steel-concrete composite beams. (2) by using the accelerated corrosion test of dry-wet cycle, the change of mechanical properties of the specimen was studied, and the change of failure form, ultimate bearing capacity, slip value, stiffness and ductility were analyzed. In this paper, the variation of mechanical properties of steel-concrete composite beams after corrosion is studied by using dry and wet cycle accelerated corrosion test, and the variation rules of cross section strain, ultimate slip, stiffness and ductility are analyzed. A formula for calculating ultimate flexural bearing capacity of partially shear-bonded composite beams after corrosion is established by introducing the coefficient of shear connection reduction k (蟻), and the experimental results and theoretical results are compared to verify the practicability of the formula. Considering the corrosion of steel beam, the deterioration of concrete performance and the decrease of shear connection degree of composite beam caused by pin corrosion, the time-varying model of resistance of composite beam is established. The time-varying reliability and durability life analysis method of steel-concrete composite beam is put forward. Taking a simply supported steel-concrete composite beam as an example, the concrete process of reliability analysis is given. The time-varying reliability index and durability service life of the structure are calculated, and the influencing factors of its reliability are analyzed.
【学位授予单位】：中南大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TU398.9;TU311.2

【共引文献】