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。     

梯形波纹钢腹板弹性剪切屈曲强度的数值模拟研究

波纹钢腹板弹性剪切屈曲强度的计算方法是腹板设计的关键问题。目前波纹钢腹板弹性剪切屈曲强度理论公式已基本成形,但公式中唯一参数n的取值存在一定争议。本文建立有限元分析模型,模拟分析出波纹钢腹板弹性剪切屈曲强度。将不同n值下的弹性剪切屈曲强度公式计算结果与数值结果进行对比,得到最优参数n值,结果表明:最优n值下的波纹钢腹板弹性剪切屈曲强度理论公式综合考虑了三种剪切屈曲模式,公式精度较高,可供工程设计参考。     

梯形波纹腹板钢梁弹性局部剪切屈曲计算分析

与平腹板钢梁相比,梯形波纹腹板钢梁腹板局部剪切屈曲性能有所提高。弹性局部剪切屈曲是梯形波纹腹板钢梁设计计算基础,本文运用ANSYS有限元计算分析梯形波纹腹板钢梁弹性局部剪切屈曲,并与经典公式进行计算对比,发现经典公式计算值与ANSYS有限元计算结果存在较大偏差。由于存在"手风琴效应",腹板承担的弯矩相对较小,以致在腹板局部剪切屈曲计算中通常被忽视,这种方法是否适用于所有梯形波纹腹板钢梁及其所造成的计算偏差值得研究。本文从荷载条件、波折角大小、腹板尺寸以及翼缘尺寸等方面对影响梯形波纹腹板弹性局部剪切屈曲的因素进行计算分析。分析表明,上述影响因素与腹板弯矩相关,而腹板弯矩的存在将影响腹板弹性局部剪切屈曲。     

波纹腹板H型钢梁柱铰接节点静力性能试验研究及有限元分析

通过对2个波纹腹板H型钢梁柱铰接节点的静力试验,分析了波纹腹板H型钢梁柱铰接节点的静力承载能力,研究了波纹腹板H型钢梁柱铰接节点各截面的内力分布,并将试验结果与传统H型钢梁柱铰接节点设计公式的计算结果进行了对比,验证了传统H型钢梁柱铰接节点设计公式的可靠性。采用有限元分析软件ABAQUS对节点进行了有限元分析,将有限元分析得到的荷载-位移曲线与试验结果进行对比,验证了有限元分析的合理性。采用ABAQUS对节点进行了参数分析,研究了端板厚度、梁连接板、柱连接板厚度与波纹断点对节点承载力的影响。研究结果表明：现有的H型钢梁柱铰接节点实用设计公式在设计波纹腹板H型钢梁柱铰接节点时安全可靠;常用的端板和连接板构造方式适用于波纹腹板H型钢梁柱铰接节点;腹板与端板焊接处波纹的断点不影响波纹腹板H型钢梁柱铰接节点的力学性能。     

波纹腹板焊接H形钢疲劳性能试验研究

设计了4根梯形波纹腹板焊接H形钢试件,依据GB 50017-2003《钢结构设计规范》的相关规定进行疲劳性能试验,并特别考虑了GB 50278-2010 《起重设备安装工程施工及验收规范》中吊车梁安装偏差的相关规定。通过ANSYS有限元分析验证试件破坏形式的合理性。研究结果表明：对于CECS 291:2011 《波纹腹板钢结构技术规程》中推荐波形的梯形波纹腹板H形钢,其疲劳性能优于平腹板H形钢,疲劳设计中可按3类钢构件进行计算,且不考虑腹板波纹转折引起的应力集中及安装偏差等施工因素的影响。     

波纹腹板H型钢组合梁抗弯性能

为研究波纹腹板H型钢组合梁的受弯性能,制作4根试件进行抗弯试验,并借助有限元软件进行辅助分析。试验结果表明,波纹腹板H型钢组合梁具有较好的塑性变形性能,截面上应力分布基本符合平截面假定,钢梁腹板基本不承受弯曲正应力,腹板上剪应力均匀分布。试验得到的极限破坏弯矩可以达到理论塑性弯矩的150%以上,钢梁腹板局部承压强度高,加载点不需要设置加劲肋。结合试验结果,按照组合梁简化塑性理论,给出了多种情况下,波纹腹板H型钢组合梁抗弯承载力的设计表达式。     

考虑荷载偏心的梯形波纹腹板工字梁弯矩修正因子

对不同荷载偏心和端部约束条件下梯形波纹腹板工字梁的弯矩修正因子进行研究。通过有限元屈曲分析获取弯曲修正因子。采用梁单元、新横截面属性公式及新梯形波纹腹板工字梁翘曲常数,建立有限元程序。将弯矩修正因子的理论结果与软件ABAQUS的壳单元模拟结果进行对比。以波纹形式和长度为参数,进行了大量有限元分析。通过数值研究,对理论结果进行验证,并将SSRC规范中的弯矩修正因子与有限元结果对比。将SSRC规范中弯矩修正因子Cb改进为Cb,c,提高了侧向畸变屈曲强度的准确性。     

梯形波纹腹板钢梁横向弯矩有限元分析

横向弯矩存在于梯形波纹腹板钢梁翼缘,在梯形波纹腹板钢梁弹性抗弯强度计算中,是否考虑翼缘横向弯矩的影响,涉及结构计算与设计的合理与安全。本文运用ANSYS有限元软件计算分析弹性范围内翼缘横向弯矩对梯形波纹腹板钢梁抗弯强度的影响,并对影响参数进行了论述。对有限元分析与理论公式进行了计算对比,两种方法的合理性得到相互论证。可运用上述两种计算方法确定是否在弹性抗弯强度计算中考虑翼缘横向弯矩的影响。     

波纹腹板H型钢梁的腹板受力分析

H型钢腹板强度与稳定性之间的矛盾是长期困扰工程界的一个难题,文中所研究的全波纹腹板H型钢在一定程度上缓解了这个矛盾。文中根据能量原理分析计算了承受均布下的全波纹腹板H型钢梁的腹板屈曲强度,给出了波纹腹板弹性失稳的临界公式,用实例说明了全波纹腹板H型钢的优越性,为这种H型钢在工程中的应用提供了理论依据。     

波纹腹板H型钢在建筑的中应用

波纹腹板H型钢是将普通H型钢的腹板改成具有类似正弦、梯形或三角形等波形成周期重复排列的腹板,它既能保证强度、稳定,又可降低用钢量,减轻自重,具有良好的经济优势。本文结合工程实际案例,利用pkpm软件建立两种形式门式刚架模型,得出相同工况下波纹腹板钢比H型钢可节省用较大用钢量的结论。     

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.     

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 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.     

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.     

预应力钢梁与波纹板的叠加效应

利用在役混凝土结构和钢结构的优点开发多种类型的组合构件,以提高结构构件的延性和适用性。混合型钢梁为类型之一,采用预应力法对该钢梁进行研究。对现有的Ⅰ形钢梁施加预应力,但是由于截面轴向刚度较大,使得预应力效果很小。另外,如果使用波纹板,由于叠加效应,加在主要抗弯构件(上、下翼缘)上的预应力会被放大,因此,这不仅对构件的适用性,而且对提高其抗弯强度都是有利的。然而,之前有关施加预应力后对波纹板钢构件的大量研究重点都放在波纹板的剪切屈曲强度上,很少涉及波纹板和梁的叠加效应。因此,本研究提出两个合理的理论模型以定量评估叠加效应,通过在波纹板钢梁中施加预应力,对2根波纹板钢梁和1根具有标准宽翼缘截面的钢梁进行了试验研究。试验结果表明,与典型板钢梁相比,波纹板钢梁的预应力效应增加得更为显著,给出的方法被证实非常简单,并与试验结果吻合较好。     

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.     

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.     

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。