钢—混凝土组合箱梁及其框架结构的静动力性能分析

发布时间：2018-04-22 09:25

本文选题：组合箱梁及框架结构 + 静力性能　；参考：《中南大学》2013年博士论文

【摘要】：钢-混凝土组合箱梁在桥梁工程和高层建筑中已经得到了广泛的应用,目前国内外关于钢-混凝土组合箱梁的静动力性能研究存在的问题有：考虑剪力滞效应的钢-混凝土组合箱梁解析方法及梁段有限元法研究主要集中于工字形组合梁、关于组合箱梁畸变屈曲临界弯矩的计算方法过于复杂、考虑剪力滞效应的动力响应计算方法尚未见报道、弯矩-曲率恢复力模型大都基于构件、弹塑性地震响应时程分析大多基于层模型等,理论研究严重滞后于工程实践,开展考虑剪力滞效应的钢-混凝土组合箱梁的静动力性能试验研究和理论分析,可推广钢-混凝土组合箱梁在桥梁工程和超高层建筑中的应用。本文针对目前研究现状开展的主要研究工作如下： (1)在考虑混凝土板和钢梁底板因剪力滞效应引起的纵向翘曲、钢梁剪切变形及钢梁与混凝土板间界面滑移的基础上,应用能量变分原理导出钢-混凝土简支组合箱梁受横向荷载作用下的剪力滞控制微分方程和边界条件,获得横向荷载作用下的箱梁应力、挠度和滑移解析解。根据虚功原理,提出同时考虑滑移效应、剪力滞及剪切变形效应的组合梁单元及等效节点力向量,编制组合梁梁段有限元程序。应用本文解析解分别对集中荷载和均布荷载作用下的组合箱梁应力、挠度和滑移进行计算,并同现有试验结果进行比较,验证本文解析解及梁段有限元法的正确性。利用本文计算方法对混凝土顶板及钢梁底板剪力滞系数进行参数分析,并在大量计算数据基础上提出较为准确的混凝土顶板及钢梁底板剪力滞系数经验计算公式。 (2)考虑钢-混凝土组合箱梁负弯矩区钢梁侧向弯曲屈曲及侧向弯扭屈曲两种重要屈曲模式,在建立钢梁腹板对钢梁底板的转动约束刚度及侧向约束刚度的计算方法的基础上,结合薄壁杆件的屈曲理论提出钢-混凝土组合箱梁负弯矩区的侧向弯曲屈曲弯矩及侧向弯扭屈曲弯矩计算方法。通过实例分析现有计算方法存在的理论缺陷,验证本文计算方法的实用性和适用性。 (3)综合考虑组合箱梁剪力滞、滑移、剪切变形和转动惯量等多重因素的影响,推导组合箱梁的控制微分方程及自然边界条件,获得儿种常用边界条件的组合箱梁固有频率方程,提出一种能对工程中常用组合箱梁自振特性进行分析的方法,通过算例验证该方法的有效性；利用中心差分法对振动微分方程进行求解,获得组合梁在任意荷载作用下的动力响应,通过算例将差分数值计算结果与ANSYS有限元计算结果进行比较,证明该方法的正确性。 (4)进行4根不同剪力连结度及腹板高厚比钢-混凝土简支组合箱梁低周反复荷载试验研究,对钢-混凝土组合箱梁的破坏形态、滞回规律、骨架曲线、延性、耗能能力、刚度退化规律等抗震性能进行深入的分析,重点考察剪力连结度及腹板高厚比对钢-混凝土组合箱梁抗震性能的影响；考虑剪力连接度和界面滑移的影响,提出组合箱梁正向、负向截面弯矩-曲率弹性刚度及截面屈服弯矩计算方法,建立简单适用的组合箱梁截面弯矩-曲率骨架曲线的三折线模型,在试验数据与理论分析的基础上,获得了组合箱梁正向及负向刚度退化规律表达式,并进一步提出简单明了的钢-混凝土组合箱梁截面弯矩-曲率顶点指向型滞回模型。 (5)将本文提出的弯矩-曲率恢复力模型程序化,建立适合钢-混凝土组合箱梁的弹塑性地震分析的多段变刚度杆单元刚度矩阵和适用于组合结构数值计算的弯矩-曲率滞回模型转化关系,结合本文提出的多段变刚度杆单元刚度矩阵及弯矩-曲率滞回模型转化关系编制组合结构弹塑性地震响应时程分析计算程序。利用本文计算程序对不同设计参数的钢-混凝土全组合框架结构进行弹塑性地震动力响应计算,提出组合框架合理的抗震设计建议。
[Abstract]:Steel - concrete composite box girder has been widely used in bridge engineering and high - rise building , and there are some problems existing in the research of static dynamic performance of steel - concrete composite box beam at home and abroad .

( 1 ) In consideration of longitudinal warping caused by shear lag effect of concrete slab and steel beam bottom plate , shear lag control differential equation and boundary condition of steel - concrete simply - supported composite box girder under transverse load are derived by applying energy variational principle .

( 2 ) Considering the two important buckling modes of the lateral bending buckling and lateral bending buckling of the steel - concrete composite box girder in the negative bending moment area , the lateral bending buckling moment and the lateral bending bending moment calculation method of the negative bending moment area of the steel - concrete composite box girder are put forward based on the calculation method of the rotation constraint stiffness and the lateral restraint rigidity of the steel beam web on the steel beam bottom plate , and the theoretical defects existing in the existing calculation method are analyzed by examples , and the practicability and applicability of the calculation method are verified .

( 3 ) Considering the influence of multiple factors such as shear lag , slip , shear deformation and moment of inertia of the combined box girder , the control differential equation and natural boundary condition of the combined box girder are derived , and the natural frequency equation of the composite box girder with common boundary conditions is obtained , and a method for analyzing the self - vibration characteristics of the commonly used composite box beam in the engineering is proposed , and the validity of the method is verified by an example .
The dynamic response of the composite beam under arbitrary load is obtained by using the center difference method , and the result of the difference numerical calculation is compared with the finite element calculation result of ANSYS to prove the correctness of the method .

( 4 ) Four different shear connection degree and low - cycle repeated load test of steel - concrete simply - supported composite box girder are studied . The damage form , hysteretic rule , skeleton curve , ductility , energy consumption and stiffness degradation law of steel - concrete composite box girder are analyzed in - depth , and the influence of shear connection degree and web height - thickness ratio on the seismic behavior of steel - concrete composite box girder is investigated .
Considering the influence of shear connection degree and interface slippage , a three - fold line model of forward and negative - direction cross - section bending moment - curvature elastic stiffness and cross - section yield bending moment calculation method of combined box girder is proposed , and a simple and suitable three - fold line model of bending moment - curvature skeleton curve of combined box girder is established . Based on experimental data and theoretical analysis , the expression of positive and negative stiffness degradation law of composite box girder is obtained .

( 5 ) programming the bending moment - curvature restoring force model proposed in this paper , establishing a multi - section variable stiffness rod unit stiffness matrix suitable for the elastic - plastic seismic analysis of a steel - concrete composite box girder and a bending moment - curvature hysteresis model transformation relation which is suitable for the numerical calculation of the combined structure ;

【学位授予单位】：中南大学
【学位级别】：博士
【学位授予年份】：2013
【分类号】：TU398.9

【参考文献】