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.     

Shear behavior of partially encased composite I-girder with corrugated steel web: Numerical study

Shear behavior of partially encased composite I-girders with corrugated web has been investigated analytically and numerically in this paper. A 3-D finite element model with geometric and material nonlinearity is established and verified by the experiments. Subsequently, a parametric study is carried out to examine the effects of geometric and material properties on the shear behavior which includes corrugation, height, thickness, connection degree between steel web and concrete encasement. It is found that the ultimate shear strength of steel I-girders is improved with increases in the thickness, height and yield strength of corrugated web, while the ultimate shear strength of partially encased composite I-girders increases with the thickness, yield strength of corrugated web and the thickness, compressive strength of concrete encasement. However, the stud stiffness has little influence on the ultimate shear strength. Moreover, the concrete encasement improves the shear strength of steel I-girders, the degree of improvement increases with the thickness and compressive strength of the concrete, but decreases drastically with the thickness of corrugated web. Therefore, it is suggested that concrete should be poured on the corrugated web with thin thickness or low yield strength to prevent buckling occurrence before yielding of steel web. Finally, shear strength prediction equations are proposed and verified by numerical results. The calculated shear strength agree well with the numerical results for steel I-girders before and after composite with concrete, which indicates that the proposed analytical equations can be applied to predict the shear strength of such partially encased composite girders with corrugated web.     

Application of corrugated plates as the web of steel coupling beams

Nowadays, steel coupling beams are used as an efficient alternative to reinforced concrete (RC) coupling beams. Particularly in the coupled shear walls system, coupling beams are the main members for dissipating seismic energy. In this paper, for the first time the application of corrugated plates as the web of steel coupling beams (rather than flat web and its stiffeners) is studied as a proposition for improving seismic behavior of such beams. The study addresses the linear elastic buckling analysis and non-linear analysis of steel coupling beams with flat and corrugated webs using finite element technique for which ANSYS software is employed. 160 models have been studied, considering parameters such as shape of web plate (flat and three corrugated types, including trapezoidal, curved, and zigzag), web thickness, number of corrugations, and corrugation angle. The finite element results are validated through comparison with the experimental results of a common steel coupling beam, tested by other researchers. In addition to the advantages of eliminating web stiffeners, results of this study show that the application of corrugated web with the proposed geometric criteria makes it possible to achieve further rotation capacity in comparison with common steel coupling beams. Finally, a design approach for corrugated web of steel coupling beams, accompanied by a practical example, is presented.     

Shear capacity of plate girders with trapezoidally corrugated webs

In this paper, the shear capacity of plate girders with trapezoidally corrugated webs is numerically studied using a non-linear finite element method. Effects of large deflections are taken into account and a perfectly elastic-plastic material model obeying a von Mises yield criterion is assumed. The following geometric parameters that influence the shear capacity of such girders are investigated: (1) the overall dimension of the web panel; (2) the web thickness; (3) the corrugation depth of the web; (4) the corrugation angle; and (5) the width of the plane sub-panel of the web. More specifically, the influence of these parameters both on the ultimate shear capacity and on the remaining shear capacity in the post-buckling range, as well as on the buckling modes, are reported. Based on the numerical results, empirical formulae that were proposed earlier for the prediction of the shear capacity are examined and suggestions for an optimal design of such girders in shear are given.     

Nonlinear analysis for PC box-girder with corrugated steel webs under pure torsion

A three dimensional finite element model of PC box-girder with corrugated steel webs taking material nonlinearity into consideration is established to investigate the behavior under pure torsion. The torque–twist curves and ultimate torsional strength predicted by FEM show good agreement with test data. Results obtained from finite element model indicate that specimens go through three stages subjected to pure torsion and the shear flow in concrete top or bottom flange is not equal to that in corrugated steel webs. Parametric study is carried out including effect of corrugation, effect of thickness of web, effect of strength of concrete, and effect of prestressed tendons. It is shown that the ultimate torsional strength of specimens is in linear proportion to shear modulus and thickness of corrugated steel webs and to compressive strength of concrete.     

Shear strength of trapezoidal corrugated steel webs

Corrugated webs are used to increase the shear stability of the steel webs of beams and girders and to eliminate the need for transverse stiffeners. This paper focuses on the shear strength of corrugated steel webs with trapezoidal corrugations. Previously developed formulas for predicting the shear strength of steel trapezoidal corrugated webs, along with the corresponding theory, are summarized. A new formula is developed, which considers interaction among the various shear failure modes. More than 100 test results from previous research are organized and evaluated according to relevant test specimen parameters. The conditions of many of these tests are found to be inconsistent with the theoretical conditions assumed in deriving the shear strength formulas. The various formulas for predicting shear strength are then compared with selected test results. The new formula is shown to be more accurate than previous formulas for estimating the shear strength of corrugated steel webs.     

Basic parametric study on corrugated web girders with cut outs

This paper presents a basic parametric study on steel girders with trapezoidally corrugated webs having cut outs. A finite element analysis is carried out to investigate the effect of cut outs in corrugated webs. This FE-modelling is conceived in ANSYS because of the program’s significant capability to account for the web stresses and out-of-plane buckling failure modes. The Finite element model of corrugated web plates is calibrated with theoretical study and finally a parameter study with a scope of application of cut outs in girders with corrugated web plates is performed. This procedure includes the influence of web height, length of parallel part, depth of corrugation, web configuration, location of cut out and its diameter. The analytical study shows that the influence of geometry of corrugated sheets with cut outs on the load capacity and buckling behaviour of the girder can be significant. With the help of the finite element model, the eigenvalue buckling analysis is carried out for all parameter combinations. The local buckling coefficients and the accompanying failure mechanisms are determined for several heights of web and for a wide range of the horizontal eccentricity of the cut out. With the help of this numerical research, design specifications are recommended in line with Eurocode 3.     

具有钢翼缘的波形钢腹板的面内刚度计算

针对波形钢腹板与混凝土板的连接形式,通过有限元模拟分析,提出对于具有钢翼缘的波形钢箱梁应考虑其腹板面内刚度的必要性。通过对国外已建34座波形钢腹板箱梁桥的腹板进行统计分析,得出波形钢腹板面内刚度受波形腹板的腹板高度与腹板厚度比值的影响较大的结论,并引入“有效宽度”的概念,提出了能包罗常用波形腹板有效宽度的简单有效的面内刚度计算公式。     

梯形波纹钢腹板的剪切强度

波纹腹板用于提高钢梁腹板剪切稳定性,同时避免横向加劲。研究梯形波纹钢腹板的剪切强度,总结了以往梯形钢腹板的剪切强度公式及相应理论。提出新的剪切强度公式,考虑不同剪切失效模式的相互影响。根据相关试验的试件参数,对100多个试验结果进行整理和分析。大多数试验条件都与剪切强度公式中的理论条件假定不一致。将这些公式与试验进行对比,结果表明:新公式更精确。     

梯形波纹钢腹板的剪切强度

波纹腹板用于提高钢梁腹板剪切稳定性和避免横向加劲。研究梯形波纹钢腹板的剪切强度,总结了以往梯形钢腹板的剪切强度公式及相应理论。提出新的剪切强度公式,考虑不同剪切失效模式的相互影响。根据相关试验的试件参数,对100多个试验结果进行整理和分析。大多数试验条件都与剪切强度公式中的理论条件假定不一致。将这些公式计算结果与试验结果进行对比,结果表明:新公式更精确。     

波形钢腹板PC组合箱梁在玉春桥中的应用研究

针对一座波形钢腹板PC组合箱梁桥——玉春车行天桥,对其波形钢腹板和抗剪连接键的设计与构造进行了介绍,并对波形钢腹板和抗剪连接键的受力性能进行了计算分析,计算结果表明,在正常使用极限状态下,钢板的剪应力满足规范要求,且不会在钢板剪切屈服之前发生局部屈曲、整体屈曲或合成屈曲的破坏形式;剪力连接键的抗剪承载能力满足使用要求且具有较大的安全裕度。     

部分混凝土外包波形钢腹板组合工字梁的抗剪性能试验研究

针对提高负弯矩作用下连续梁的结构特性提出了一种新型的部分混凝土外包波形钢腹板组合工字梁。对这种混凝土外包组合工字梁在对抗荷载下的抗剪性能进行试验分析研究。试验结果显示与普通的工字梁相比,混凝土外包组合工字梁的剪切屈曲因受外包混凝土的限制而有了更好的抗剪强度。由于组合截面的抗剪刚度是基于波形钢腹板和破裂前外包混凝土平均厚度的总和,且其抗剪强度决定了由钢腹板和外包混凝土共享的抗剪强度比。此外,根据试验中的破坏模式和应变分布,提出部分混凝土外包波形钢腹板组合工字梁的预估抗剪强度。试验结果验证了之前分析得出的弹性阶段的抗剪刚度和抗剪比。且之前计算得出的钢腹板与组合梁的抗剪强度也与试验结果一致。通过对比可知文中提到的分析方法可以应用到部分混凝土外包波形钢腹板组合工字梁结构的抗剪刚度预估和抗剪强度设计中去。     

Shear buckling in foam-filled web core sandwich panels using a Pasternak foundation model

Web core panels, foam-filled sandwich panels with interior webs, are a structurally efficient option for transverse load bearing applications. In web core panels, the interaction between the webs and core material can have a substantial impact on web shear buckling strength and is a key element of lightweight structural design. The present work is an investigation of web buckling behavior in web core panels under a distributed load. To solve this problem, web shear buckling was analyzed for the case of pure shear loading with foam support, and this analytic model was extended to the case of panels with a transverse distributed load. The webs are modeled as simply supported plates resting on a Pasternak elastic foundation. To that end, a buckling model for plates on a Pasternak foundation is presented, along with closed-form approximations of the solution for square and infinitely long plates. An accurate model for the foundation constants is developed using energy methods. Applicability of the plate buckling model to web core panels with transverse loads is presented via a finite element study. In panels, the slenderness and spacing of the webs have a slight effect on the boundary conditions between the webs and face sheets. The effect is relatively small, however, and the model presented in this work underpredicts buckling strength by less than 25%. The model in this work is thus a reasonable approach to the practical design of web core panels.     

Seismic Behavior Investigation of the Corrugated Steel Shear Walls Considering Variations of Corrugation Geometrical Characteristics

The corrugated steel plate shear walls have recently been proposed to address the seismic issues associated with simple steel plate shear walls; however, stiffness, strength, and ductility of the corrugated shear walls are significantly affected by varying the corrugation geometry under seismic loading. The present study investigates steel shear walls’ models with corrugated or simple infill plates subjected to monotonic and cyclic loads. The performance of the corrugated steel plate is evaluated and then compared to that of the simple steel plates by evaluating the damping ratios and energy dissipation capability. The effect of corrugation profile angle, the existence of an opening, and the corrugation subpanel length are numerically investigated after validation of the finite element modeling methodology. The results demonstrate that incorporating corrugated plates would lead to better seismic damping ratios, specifically in the case of opening existence inside of the infill plate. Specifically, the corrugation angle of 30° decreases the ultimate strength, while increasing the initial stiffness and ductility. In addition, the subpanel length of 100 mm is found to be able to improve the overall performance of shear wall by providing each subpanel appropriate support for the adjacent subpanel, leading to a sufficient buckling resistance performance.     

波形钢腹板梁边缘的应力分布

波形钢腹板因其很多良好的性能而在结构中应用广泛。由于波形钢腹板在边缘和腹板的正态分布和剪应力分布与受平面挠曲与剪力影响的传统工字梁的应力分布不同,对波形钢腹板梁边缘的应力分布进行重点分析。在波形钢腹板边缘出现的附加的横向弯曲力矩,会导致对抗弯力矩有一定影响的附加正应力的分布。附加的横向弯曲力矩来自波形钢腹板中的剪力,它的数值取决于波形剖面的几何特征。对这种横向弯曲力矩的影响和趋势进行了分析。根据试验背景构建一个数值模型用来分析边缘的应力分布。测定附加正应力的趋势,并根据数值结果提出一个改进的设计方法来确定横向弯曲力矩和附加的正应力。     

Stress distribution in the flanges of girders with corrugated webs

The corrugated steel plate is a widely used structural element in many fields of application because of its numerous favorable properties. Due to the web corrugation the normal and shear stress distribution in the flange and web plates are different from the stress distribution of the conventional I-girders under in-plane bending and shear. The focus of this paper is the analysis of the stress distribution in the flanges of the girders with corrugated webs. Due to the corrugated web an additional transverse bending moment arises in the flange, which results in an additional normal stress distribution what has an effect on the bending moment resistance. The additional transverse bending moment comes from the shear force in the corrugated web and its value depends on the geometry of the corrugation profile. The effect and the tendency of this transverse bending moment are analyzed in the current paper. Based on experimental background a numerical model is developed to analyze the stress distribution in the flanges. Tendency of the additional normal stresses are determined and based on the numerical results an enhanced design method is proposed to determine the transverse bending moment and the additional normal stresses.     

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。     

波纹钢腹板组合箱梁桥力学性能研究现状及发展

波纹钢腹板组合箱梁桥以波纹钢代替普通混凝土作为腹板,可有效减轻桥梁自重,提高跨越能力,近几十年来得到广泛关注和深入研究。对国内外关于该组合结构的波纹钢腹板力学性能、整体静力学性能、动力学性能、疲劳性能及剪力连接件和转向块等方面的研究现状及成果进行总结、分析。指出:波纹钢腹板组合箱梁体外预应力筋的应力增量、组合箱梁几何参数对其力学性能影响的综合分析、剪力连接件几何参数对其力学性能的影响及剪力连接件在重复荷载下的力学行为规律等方面是需要进一步研究的课题。     

工字梁的抗剪极限承载力

对工字梁腹板抗剪极限承载力的研究进行总结,对各种公式与文献中的试验结果进行对比,将拉力场理论和转向应力场理论的假定与ANSYS分析揭示的腹板应力发展变化规律进行对比,指出了假定和数值分析结果的不一致。提出了翼缘对腹板转动约束的合理参数,得到精度良好的考虑翼缘约束的腹板剪切屈曲系数。利用得到的屈曲系数,考虑翼缘抗弯承载力的贡献,提出新的工字梁抗剪极限承载力的计算公式。与现有试验数据和ANSYS非线性有限元分析结果的对比,证实建议方法离散性较小,适用范围广,尤其是对于通用高厚比较大的梁,较以往方法有了较大改进。