【作者】 刘鸿儒；

【导师】 李忠献；

【作者基本信息】 天津大学 ， 结构工程， 2007， 硕士

【摘要】 与钢筋混凝土结构相比,型钢混凝土结构具有承载力高、延性好的特点,因而在工程中得到了广泛的应用。然而,在强震作用下,梁端塑性铰易诱发梁柱连接焊缝发生脆性断裂,且渗透到节点核心区,从而大幅度地降低型钢混凝土结构的抗震性能。本文提出对梁端型钢翼缘进行削弱,将塑性铰从梁端转移到削弱截面部位,从而提高型钢混凝土结构的抗震性能,因而具有重要的理论意义和工程价值。本文系统地开展了翼缘削弱的型钢混凝土框架抗震性能的试验研究与理论分析,主要研究工作和创新成果包括以下三个方面:(1)翼缘削弱的型钢混凝土框架抗震性能的试验研究。基于现有规范相关规定,对梁端采取削弱的型钢混凝土框架进行了低周反复荷载试验,框架模型试验结果表现为梁铰破坏机制。其变形能力、承载能力、延性、耗能能力等受力性能均满足抗震要求。框架模型的正向延性系数达到7.34,反向延性系数达到7.4,满足一般延性框架延性系数不小于4的要求。(2)翼缘削弱的型钢混凝土框架的弹塑性分析。通过对试验框架模型进行Push-Over分析,得到了框架模型出铰顺序和杆件破坏情况,与试验所得结果比较吻合。在此基础上,修改型钢混凝土框架的多个参数获取了多种工况并分别进行Push-over分析,获得了每种工况下的出铰顺序,基底-剪力曲线,框架的承载能力、位移延性和破坏机制等框架抗震特性。通过对Push-over分析结果进行对比得出:柱与梁抗弯强度比η、轴压比n、梁型钢翼缘的削弱深度c是影响翼缘削弱的型钢混凝土框架破坏机制形成的三个主要参数。(3)翼缘削弱的型钢混凝土框架的非线性有限元分析。基于型钢混凝土的受力特点,建立了适用于反复荷载作用下的型钢混凝土材料的本构关系。考虑了材料非线性、几何非线性和刚度退化等因素的影响,采用了基于APDL参数化程序设计语言的ANSYS分析方法,对型钢混凝土框架在低周反复荷载作用下的受力性能进行了分析,与模型试验结果相比较,二者吻合较好,验证了用有限元对型钢混凝土结构进行分析的可行性和适用性。更多还原

【Abstract】 Compared with reinforced concrete (RC) structure, steel reinforced concrete (SRC) structure has characteristics of high bearing capacity and good ductility, so has been applied in engineering widely. However, under action of strong earthquake, plastic hinge at beam end may induce brittle fracture of welded joint between beam and column and entry joint core, which may reduce the seismic behavior of the SRC structure significantly. In this dissertation, reduced beam section is proposed for steel flanges at beam end so as to transfer the plastic hinge from the beam end to the reduced section. This may improve the seismic behavior of the SRC structure, and has important significance in theory and value in engineering.In this dissertation, the experimental investigation and theoretical analysis on seismic behavior of SRC frame with reduced beam sections are systematically performed, and the main research work and innovation achievements are included in the three aspects as following.(1) The experimental research on the seismic behavior of the steel reinforced concrete frame with reduced beam sections. Based on the Code recommendations an experiment on the SRC frame with reduced beam sections was performed under cyclic loading, the results of the experiment shows a beam joint damage mechanism. The deformation capacities, bearing capacities, ductility, energy dissipation capacities satisfied the seismic requests. The model frame positive ductility factor reaches 7.34 and the negative one reaches 7.4 which is satisfy the request of superior to 4 for the ductility factor of ordinary ductile frame.(2) Elastic-plasticity analysis of the steel reinforced concrete frame with reduced beam sections.Trough the push-over analysis of the experiment specimen frame, the obtained occurrence sequence of the plastic hinges and the members’failure are quite similar to experiment results. Based on that, parameters of the SRC frame has been modified to obtain many analysis cases. The occurrence sequence of each case plastic hinges and the frame seismic characteristics such as shear curve, bearing capacity, displacement ductility and failure mechanism comparison of the push-over analysis results showed: Beams and columns flexural strength ratioη、axial-compression ratio n and the reduced beam section cut depth c are the three main parameters that influence the failure mechanism of SRC frame with reduced beam sections. (3) Nonlinear finite element analysis of SRC frame with reduced beam sections. Based on the reactions characteristics of steel reinforced concrete, we establish the constitutional relationship of the steel reinforced concrete materials under cyclic loading. Considering the influence of non-linear, geometric non-linear and rigidity degradation factors, a numerical modeling with APDL program has been made to analyze the reactions capacities of the steel reinforced concrete frame under the cyclic loading. The comparison with the model experiment results shows that the two analyses are mostly identical which verify the feasibility and application of finite element to analyze steel reinforced structure.更多还原