板桁结合型加劲梁受力机理与计算理论研究

发布时间：2018-01-08 11:41

本文关键词：板桁结合型加劲梁受力机理与计算理论研究　出处：《长安大学》2015年博士论文　论文类型：学位论文

【摘要】：本文以岳阳洞庭湖大桥为背景,结合交通运输部建设科技项目《大跨径钢桁加劲梁悬索桥关键技术研究》(2013318798320),在总结国内、外已有板桁结合型加劲梁理论与试验研究成果的基础上,采用有限元仿真分析、理论推导方法对板桁结合型加劲梁的受力机理、连续化分析方法、考虑剪力滞与剪切效应的弯曲计算理论及约束扭转计算理论进行了研究。本文主要研究内容和结论如下:采用板-梁混合精细有限元方法对结合型加劲梁的受力机理进行了研究,得到了竖向桥面荷载在板桁结合型加劲梁桥面系的传递路径与传力比,研究了节间长与主桁宽度比、节间横梁数量、节点、节间横梁竖向刚度比、节点横梁与桥面板的竖向刚度比等参数变化对桥面系传力比的影响,以表格的形式给出了不同板桁结合型加劲梁几何尺寸参数对应的桥面系传力比数值,提出了桥面系传力比之间的基本关系式及竖向桥面荷载作用下上弦杆、中央纵梁与横联桁架的简化受力模式。基于能量原理推导了板桁结合型加劲梁主桁架腹杆和平联的连续化等效板厚计算公式,根据板桁结合型加劲梁连续化等效原则构造了板桁结合型加劲梁的连续化等效截面;基于刚性扭转与截面等翘曲假设,采用数值积分方法推导了板桁结合型加劲梁等效截面扭转刚度与U型肋正交异性钢桥面板的剪切等效厚度计算公式。以岳阳洞庭湖大桥为研究对象,将连续化分析方法与精细有限元法的位移与应力计算结果进行了对比,结果表明连续化分析方法具有较高的计算精度,同时大幅提高了计算效率。基于板桁结合型加劲梁连续化分析方法,建立板桁结合型加劲梁剪力滞效应分析理论模型,考虑正交异性钢桥面板法向与切向等效厚度的差异,在采用附加翘曲位移法修正加劲梁轴力平衡条件的基础上构造了板桁结合型加劲梁钢桥面板的剪力滞纵向翘曲位移函数,基于能量变分原理推导了板桁结合型加劲梁剪力滞效应控制微分方程,获得了静定板桁结合型加劲梁剪力滞效应计算公式,采用精细有限元方法验证了理论公式的正确性;最后,结合桥面板有效宽度系数定义,给出了可供设计取用的静定板桁结合型加劲梁钢桥面板有效宽度系数公式。基于能量变分原理推导了考虑剪力滞与剪切效应影响的板桁结合型加劲梁竖向挠度曲线公式,结合静定板桁结合型加劲梁算例分析了剪力滞与剪切效应对竖向挠度的提高程度,结果表明剪切附加挠度占总挠度的比例为30%~50%,而剪力滞效应附加挠度的比例不超过10%;根据板桁结合型加劲梁桁架体系的剪切与轴向受力特点,推导了主桁架、K形平联及X形平联杆件轴力计算公式;基于板桁结合型加劲梁桥面荷载传递机理,推导了“W”形横联桁架内、外腹杆的轴力计算公式。考虑钢正交异性桥面板、主桁架、平联桁架法向与切向等效厚度的差异,采用连续化方法将板桁结合型加劲梁等效为薄壁箱梁,推导了计入弦杆单元影响的薄壁单元剪切受力平衡条件,得到了约束扭转正应力与薄壁约束扭转剪力流计算公式;基于乌式第二理论的一般原则建立板桁结合型加劲梁截面的约束扭转控制微分方程,采用初参数法获得了板桁结合型加劲梁截面扭转角θ、约束扭转程度β'、约束扭转双力矩B以及截面翘曲扭矩Tω的计算公式;为了更有效的求解板桁结合型加劲梁的扭转效应,依据薄壁梁弯曲、扭转几何特征的求解过程,推导了板桁结合型加劲梁截面的弯曲、扭转几何特征参数计算公式。采用文中提出的连续化分析方法与板-梁混合精细有限元方法对大跨径悬索桥板桁结合型加劲梁的弯曲与弯扭受力性能进行了研究。得到了桥面移动荷载与横桥向风荷载作用下,悬索桥板桁结合型加劲梁整体、局部构件的变形与受力特点;对比分析了桥面板与弦杆是否结合对加劲梁变形与受力的影响;研究了结构体系对悬索桥板桁结合型加劲梁变形与受力的影响。
[Abstract]:Based on the background of Yueyang Dongting Lake bridge, combined with the research on the key technology of the Ministry of transport on the construction project of science and technology "of long span steel truss girder suspension bridge (2013318798320), in the summary of domestic and abroad, combined with the basic type of plate truss girder theory and experimental research results, analyzed by finite element simulation, theoretical derivation method of the force mechanism of the stiffening girder type of plate truss, the method of continuous analysis, bending calculation theory and the constraint of shear lag and shear effect calculation of torsion theory is studied. The main research contents and conclusions are as follows: using plate beam mixed fine finite element method to combine force mechanism of the stiffening girder is studied. The vertical load on the bridge with a plate truss composite girder deck type transmission path and the ratio of transmission, the internode length and width of the main truss, beam number of nodes, internodes, internode crossbeam vertical stiffness Ratio, vertical node beam and bridge deck stiffness ratio parameters on deck force transmission ratio, are given in the form of table force of deck plate girder with different type girder geometry parameters corresponding to the forward force transmission ratio, deck basic relationship between type and ratio vertical deck loads upper chord, longitudinal and transverse truss simplified central force model. The energy principle is derived with the formula of thick plate truss stiffening girder of the main truss type peace continuous equivalent plate based on the plate truss composite girder according to the type of continuous effect principle is constructed with continuous plate truss equivalent cross section girder; torsion and warping based on rigid section assumption, the numerical integration method is combined with the type of plate truss girder section equivalent torsional shear stiffness and equivalent thickness of U ribbed orthotropic steel deck. Formula. The Dongting Lake bridge in Yueyang as the research object, the displacement continuity analysis method and finite element method and stress calculation results were compared. The results show that the continuous analysis method has high calculation precision, and greatly improves the computational efficiency. The combination of plate truss type girder continuous method based on established plate truss composite steel girder shear lag effect analysis of theoretical model, considering the orthotropic steel deck of normal and tangential equivalent thickness difference, based on the additional equilibrium condition of warping displacement correction method of stringer on constructed plate truss composite girder deck shear lag type longitudinal warping displacement function, energy the principle of derivation of plate truss composite steel girder shear lag effect control based on the differential equations, the calculation formula of static plate truss stiffening girder with shear lag effect, using a fine To verify the correctness of the theoretical formula of the finite element method; finally, combined with the effective width of slab coefficient is defined is given for design for static plate truss composite girder type steel deck plate truss. The effective width coefficient formula of the energy variational principle is derived considering the effect of shear lag and shear effect of stiffening girder the vertical deflection curve based on the formula, combined with the static plate truss composite analyses of shear lag and shear effect to improve the degree of vertical deflection calculation results show that the shear type of beam, the additional deflection total deflection ratio of 30%~50%, and the shear lag effect of the additional deflection ratio does not exceed 10%; according to the plate girder with shear and axial type of stiffening girder truss stress characteristic, deduced the main truss, K flat and X flat with the axial force calculation formula; plate truss composite girder type bridge based on load transfer mechanism of the surface, is "W" shaped cross Combined truss, calculation formula of axial force and web members. In consideration of the steel orthotropic bridge deck, main truss, flat truss method and tangential to the difference of equivalent thickness, with the continuous method of plate truss composite girder type equivalent thin-walled box beam, thin wall shear is derived considering the influence of chord unit the force balance condition, the normal stress and the restrained torsion of thin-walled restrained torsion shear flow calculation formula; the general principles of Ukraine second theories of plate truss composite girder type section constrained torsion control differential equation based on the plate truss composite girder type cross-section twist angle using the initial parameter method, constrained torsion the degree of beta ', B and double moment torsion warping torque calculation formula of T.; in order to reverse the effect of stiffening girder plate truss combined to solve more effectively, on the basis of thin-walled beam bending, torsion process of solving the geometrical characteristics of the plate is deduced With curved truss stiffening girder section, calculation formula of torsional geometric characteristic parameters. With the continuous analysis method proposed in this paper and board - beam hybrid fine finite element method of long-span suspension bridge with truss bending and torsion type girder's force were studied. The effects of the moving loads on the bridge deck and cross bridge wind load, suspension bridge with truss girder type whole deformation characteristics of local components and stress; comparative analysis of the bridge deck and chord combined effects on girder deformation and stress; study the structure system combined with the influence of deformation and stress of girder type of suspension bridge truss.

【学位授予单位】：长安大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U441

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