波形钢腹板组合箱梁剪力滞及剪切变形分析模型

为分析波形钢腹板组合箱梁的应力及变形,提出了考虑轴向平衡条件、翼板剪力滞效应和腹板剪切变形的分析模型.在位移场中增加截面纵向位移考虑轴向平衡条件.分别引入剪力滞强度函数及截面转角,以俘获剪力滞效应及剪切变形.采用虚功原理建立组合箱梁分析的控制微分方程,进而推导位移变量的解析表达式.利用三维有限单元模型的结果验证文中提出...     

波形钢腹板PC连续组合梁剪力滞效应研究

波形钢腹板不能抵抗轴向力作用,波形钢腹板PC组合箱梁的剪力滞效应与PC箱梁不同。依托一箱九室波形钢腹板PC组合连续箱梁桥,建立了有限元模型,分析了荷载作用下混凝土顶底板的剪力滞效应。结果表明,波形钢腹板PC组合箱梁顶、底板均具有正剪力滞效应,顶板剪力滞更为明显;在支点具有横隔梁构造的情况下,箱梁跨中截面剪力滞较大,在设计时需要给予注意。     

波形钢腹板组合箱梁桥剪力滞效应研究

波形钢腹板组合箱梁由于其力学性能和经济性能比普通箱梁优越而正被广泛地使用,本文介绍了计算波形钢腹板组合箱梁桥剪力滞系数的能量变分法,用有限元分析软件ANSYS进行了波形钢腹板组合箱梁桥的建模,并采用能量变分法的结果加以验证。结果表明采用有限元法模拟波形钢腹板组合箱梁桥的剪力滞效应效果较好,分析了波形钢腹板组合箱梁桥横桥向和纵桥向剪力滞系数的变化规律。     

波形钢腹板PC组合箱梁的剪滞效应特性分析

由于波形钢腹板相对于混凝土腹板的独特优点,在国外得到比较广泛的应用,在我国已建成两座波形钢腹板箱梁桥。就波形钢腹板PC组合箱梁的剪力滞效应进行分析,并与混凝土箱梁作比较,说明两者在腹板与顶板、底板连接处剪力滞效应的区别。还对泼河大桥桥跨结构作剪力滞效应的分析。     

大跨径波形钢腹板组合箱梁桥剪力滞效应

为了研究大跨径波形钢腹板组合箱梁桥的剪力滞效应,结合1座采用悬臂施工的大跨径波形钢腹板箱梁桥,分别建立平面杆系有限元模型和空间实体有限元模型,模拟施工过程,选取3个关键截面,研究了波形钢腹板组合箱梁桥在不同施工阶段的剪力滞效应分布规律。结果表明:大跨径波形钢腹板组合箱梁桥的剪力滞效应随着施工阶段的推移是一个动态变化过程,在悬臂施工阶段,剪力滞效应变化较快,在施工阶段后期,剪力滞效应变化缓慢;最大剪力滞效应发生在最大悬臂状态时的端部截面。     

考虑腹板剪切变形的波形钢腹板组合梁翼缘有效宽度计算方法

波形钢腹板组合梁在竖向荷载作用下会产生较大的腹板剪切变形,从而影响梁的内力分布和剪力滞效应,但目前针对该类型梁的剪切变形还缺乏理论研究。为此,首先在等高度波形钢腹板组合梁剪力滞效应分析方法的基础上推广至变高度梁,然后借助该方法以一等高度连续梁为对象,计算了欧拉梁理论、铁木辛柯梁理论、实体有限元3种不同内力解情况下的翼缘有效宽度系数,并与有限元法验证结果进行了对比。结果表明,采用实体有限元内力解时精度最高,其次为采用欧拉梁内力解,铁木辛柯梁内力解精度最低。最后以一变高度连续梁为对象,研究了欧拉梁理论与铁木辛柯梁理论内力解情况下的翼缘有效宽度系数,结果表明,腹板剪切变形对变高度梁翼缘有效宽度影响不大。     

考虑界面滑移效应的波形钢腹板箱梁解析解

为研究界面滑移效应对改进型波形钢腹板箱梁的影响,考虑腹板剪切变形及截面轴力自平衡条件建立了组合箱梁桥的控制微分方程,进而推导出简支箱梁的滑移位移函数和翼缘板最大纵向位移差函数表达式。以受均布荷载的改进型波形腹板组合箱梁为算例,基于箱梁荷载工况和边界条件,得到了组合箱梁桥挠度、上下翼缘板截面正应力和剪滞系数表达式。利用有限元软件,通过在翼缘和腹板间添加弹性连接单元模拟滑移效应,验证提出的理论方法的正确性。最后,采用推导的理论公式研究了剪切抗滑移刚度对组合箱梁桥截面正应力、剪滞系数和挠度的影响规律。结果表明：理论解与有限元模拟结果吻合较好,提出的理论公式可用于结构设计或软件开发;剪切抗滑移刚度对组合箱梁翼缘截面正应力及挠度影响较大;在均布荷载作用下,与不考虑滑移效应相比,考虑滑移效应后的上翼缘截面正应力减小7.44%,下翼缘截面正应力增大6.79%,箱梁桥跨中挠度增大8.8%;剪切抗滑移刚度对组合箱梁翼缘板剪滞系数的影响较小,影响幅度在1%以内。     

钢底板波形钢腹板组合箱梁桥剪滞效应分析

研究对象采用中川机场在建钢底板波形钢腹板组合箱梁桥,并将钢底板等效为混凝土底板,探讨了荷载作用对钢底板波形钢腹板组合箱梁的剪力滞效应的影响。分别对箱梁顶板、悬臂板和底板取纵向位移差函数,箱梁纵向位移差函数设为三次抛物线。运用能量变分法推导出了顶、底板剪力滞效应的体系总势能。利用最小势能原理得出了简支梁在弯曲荷载作用下的微分方程,进一步得出了集中荷载下简支箱梁位移及截面应力解。建立了实际桥梁精细化有限元模型,进行了加载试验验证。讨论了该桥跨中截面顶底板纵向正应力、剪力滞系数的变化规律。结果显示,跨中截面位移及其顶底板应力分布三者结果吻合良好。通过有限元分析和模型试验验证本文方法的正确性,为钢底板波形钢腹板剪力滞效应分析提供有效方法。     

单箱多室波形钢腹板组合箱梁腹板剪力分配理论

提出了一种利用剪力分配系数来计算单箱多室波形钢腹板组合箱梁在横向对称竖向荷载作用下腹板剪应力的方法.首先基于波形钢腹板不抵抗轴力的特点和箱梁平截面假定,用微元体平衡方程和变形协调条件建立了单箱多室截面波形钢腹板箱梁腹板剪力流的计算方程,然后基于该方程提出了腹板剪力分配系数的计算方法.以深圳南山大桥、郑州朝阳沟特大桥、河...     

波形钢腹板PC组合箱梁力学特性分析

以30 m跨径波形钢腹板桥的设计图纸为依据,进行了试验梁的设计与制作,通过理论分析方法,研究了波形钢腹板PC组合箱梁的力学特性,分析了组合箱梁的正应变分布以及钢腹板的剪切破坏形式,并总结了波形钢腹板组合箱梁桥的受力性能,为波形钢腹板组合箱梁结构的分析设计提供参考。     

单箱三室波形钢腹板悬臂梁扭转与畸变分析及试验研究

为研究单箱三室波形钢腹板箱梁悬臂状态下的扭转与畸变性能,以乌曼斯基第二理论和箱梁理论为基础,考虑了波形钢腹板的褶皱效应对箱梁纵向刚度的影响,推导了单箱三室波形钢腹板悬臂梁扭转与畸变微分方程,并采用初参数法及弹性地基梁比拟法求解了约束扭转和畸变产生的翘曲正应力和剪应力计算式。通过1片单箱三室波形钢腹板双悬臂梁进行了偏载和对称加载试验,验证了扭转与畸变翘曲应力计算公式的正确性。最后,利用推导的理论模型,分析了梁高、箱室宽度及波形钢腹板厚度等参数对偏载作用下单箱三室波形钢腹板组合箱梁截面翘曲应力的影响。研究结果表明：提出的理论计算公式可用于准确计算单箱三室波形钢腹板悬臂梁扭转与畸变效应;悬臂梁翘曲正应力主要由畸变变形引起,而约束扭转主要产生翘曲剪应力,且悬臂梁扭转和畸变产生的翘曲正应力值和剪应力值与弯曲正应力和剪应力的比值较大,因此,单箱三室波形钢腹板悬臂状态下扭转和畸变产生的翘曲正应力和剪应力不可忽略;梁高和箱室宽度对单箱三室波形钢腹板的翘曲应力影响较为显著,波形钢腹板厚度对其几乎没影响。     

考虑腹板剪切变形及滑移的波形钢腹板梁理论模型

在采用栓钉等柔性剪力连接件的波形钢腹板组合梁中,由于波形钢腹板较大的剪切变形及双界面剪切滑移,平截面假定不再适用。为此,通过将波形钢腹板梁的弯曲分解为顶底板整体满足平截面假定的主弯曲和顶底板各自满足平截面假定的次弯曲,引入波形钢腹板的剪切变形协调条件和界面剪切滑移关系,推导了考虑波形钢腹板剪切变形及界面滑移的波形钢腹板梁弹性弯曲微分方程,利用给出的横隔板对次弯曲和滑移的约束边界条件,求得了简支波形钢腹板梁在不同荷载作用下的解析解,并采用有限元分析予以验证。在此基础上,分析了横隔板及滑移对梁体弯曲性能的影响。结果表明：横隔板约束对梁体变形影响很小,但会使其附近梁段顶底板出现应力集中;当界面剪切刚度系数大于0.9时,在高跨比1/20~1/10范围内,考虑滑移与不考虑滑移梁跨中挠度比小于1.05;界面剪切刚度系数越小,横隔板附近梁段顶底板应力集中越严重。     

Shear strength of trapezoidal corrugated steel webs

Shear strength of trapezoidal corrugated steel webs is an important issue for the design of box girder bridges with trapezoidal corrugated steel webs. Eight H-shape steel girders with trapezoidal corrugated webs are firstly tested to investigate the shear behavior of webs. An extensive parametric study based on the linear elastic buckling analysis is then conducted to derive the simplified formula for calculating the elastic shear buckling strength of trapezoidal corrugated steel webs considering three different shear buckling modes. The proposed formula can give more satisfactory results for predicting the elastic shear buckling strength than some available formulae provided in the literature when compared with the numerical results. Furthermore, the nonlinear buckling analysis is conducted to intensively investigate the shear strength associated with initial geometric imperfections, and the formulae of the shear strength are proposed. Good agreements can be observed between the results calculated using the proposed prediction formula in this paper and the experimental results, and a design formula is also recommended for the routine shear design of trapezoidal corrugated steel webs.     

Shear strength and design of trapezoidally corrugated steel webs

Due to the accordion effect, corrugated steel webs are only able to resist shear force. The shear force in the web can cause three different buckling modes: local, global and interactive shear buckling. Although several researchers have been investigating it, the shear buckling behavior of the corrugated webs has not yet been clearly explained, this leads to conservative design. This paper presents the shear strength and design of trapezoidally corrugated steel webs. Firstly, global shear buckling equations are rearranged in order to derive the global shear buckling coefficient. The interactive shear buckling coefficient and the shear buckling parameter for corrugated steel webs are then proposed based on the 1st order interactive buckling equation. The inelastic buckling strength is determined from the buckling curves based on the proposed shear buckling parameter. A series of tests are conducted to verify the proposed design equations. From the test results of this study and those provided by previous researchers, it was found that the proposed shear strengths provide good predictions for the shear strength of the corrugated steel webs.     

Accordion effect of prestressed steel beams with corrugated webs

Various types of composite members have been developed to utilize the combined advantages of existing reinforced concrete and steel structures, and to actively improve ductility and serviceability of structural members. One of them is the hybrid-type steel beam, in which the prestressing method is applied to a steel beam. Introducing prestress to the existing I-shaped steel beam, however, results in a very low prestress efficiency due to the large axial stiffness of the section. On the other hand, if corrugated webs are used, the prestress introduced to the main flexural-resistant elements—the upper and lower flanges—gets larger due to the accordion effect, so that it is very advantageous not only in terms of serviceability, but also of achieving the improved flexural strength. Most previous studies on steel members with corrugated webs, however, have focused on the shear buckling strength of the corrugated webs, and few studies have been conducted on the accordion effect of the corrugated webbed beam to which prestress is introduced. Therefore, this research proposed two rational and theoretical models to quantitatively estimate the accordion effect, which is induced by the introduction of prestress to corrugated webbed steel beams, and performed experiments on two steel beams with corrugated webs and one with typical wide flange section. The experimental results showed that the prestressing efficiency of steel beams with corrugated webs increased more significantly than that of the steel beam with a typical web, and it is verified that the proposed methods are very simple and provide good agreements with the experimental results.     

Shear buckling strength and design of curved corrugated steel webs for bridges

This paper presents the shear buckling strength and design of curved corrugated steel webs for bridges considering material inelasticity. The inelastic buckling strength is determined from buckling curves based on the proposed shear buckling parameter, which is a function of the elastic shear buckling strength of steel web and the material shear yielding strength. A finite element analysis is carried out to study the geometric parameters affecting the shear buckling strength of curved corrugated steel webs for bridges. Based on the numerical results, a shear buckling parameter formula is proposed with no need to calculate either local, global, or interactive buckling parameters. But it depends on the geometric properties of the curved corrugated web profile. Another formula is presented to maximize the shear buckling capacity of curved corrugated web. The proposed formulae agreed well with the published experimental data. The curved corrugated webs produce a tremendous increase in the shear buckling strength and considerable weight saving in regard to the corresponding trapezoidal corrugated webs. The corrugation angle has a considerable effect on the behavior of curved corrugated webs, where higher corrugation angles produce a tremendous increase in the shear buckling strength of curved corrugated webs. It was found that the proposed approach provides a good prediction for the shear buckling strength of curved corrugated steel webs of bridges.     

Mechanical behavior and analysis of composite bridges with corrugated steel webs: State-of-the-art

The composite bridges with corrugated steel webs have excellent properties, such as lightness of girders, efficiency of introducing prestress forces, short construction period, optimum force distribution, good seismic performance, and aesthetics appearance etc., which have greatly promoted the application of such bridges. The objective of this paper is to provide and summarize important references related to the analysis, design and construction of composite bridges with corrugated steel webs. Subjects discussed in this review include (1) structural configuration and application; (2) shear behavior; (3) bending behavior; (4) torsional behavior; (5) patch loading resistance; (6) dynamic behavior; (7) long-term behaviors including fatigue and creep; (8) component connections; (9) analysis method and theory; (10) new concept application. The literature survey presented herein mainly focuses on papers written in English, Japanese, German and Chinese in relation to composite bridges with corrugated steel webs.     

波形钢腹板PC组合箱梁抗扭性能试验

通过试验的方法,研究波形钢腹板PC组合箱梁在偏心荷载作用下,挠度、横向位移、刚性扭转角、箱梁截面的翘曲应变、翘曲应力及波形钢腹板的附加剪应力的分布规律,以了解悬臂波形钢腹板PC组合箱梁在扭转作用下的力学性能。研究表明:波形钢腹板翘曲应变很小,可忽略不计;翘曲应力在底板上呈现明显的直线分布规律,且最大值出现在底板的角点处;波形钢腹板上的剪应力分布较均匀,附加剪应力在腹板上的分布也有类似的规律。     

波形钢腹板体外预应力组合梁正截面承载力及应力分布特征研究

为研究预应力状态下波形钢腹板组合梁的截面应力分布特征,设计制作2根波形钢腹板组合梁,在预应力筋张拉过程中研究了预应力对组合梁受弯截面应力分布特征的影响,通过正截面受弯试验对试件塑性承载力先进行测定;对体外预应力组合梁正截面承载力进行了理论分析;利用有限元分析软件,对与试件同类型的波形钢腹板体外预应力组合梁的塑性受弯承载力进行了参数分析,研究了腹板高度和混凝土强度对正截面承载力的影响。结果表明：预应力对此类构件的翼缘应变变化量影响较波形钢腹板的大约2~3倍;预应力损失对截面中性轴位置变化影响可忽略不计;施加预应力将使波形钢腹板组合梁的受弯承载力提高约30%,腹板高度等参数与此类结构跨中截面承载力呈线性关系;理论值与有限元模拟结果吻合良好,验证了所提出正截面承载力理论的准确性。