弯剪共同作用下蜂窝梁腹板弹性屈曲分析

发布时间：2018-05-27 12:43

本文选题：蜂窝梁 + 弯剪共同作用　；参考：《西南石油大学》2016年硕士论文

【摘要】：蜂窝梁是一种由工字形梁在腹板上进行切割后错位焊接或直接切割成不同孔型的开孔梁,其开孔形式主要有圆形、正六边形、正八边形等。蜂窝梁相比实腹梁有许多的优势,比如抗弯刚度大、截面模量高、经济效应好、便于配置管道设施以及构件美观等。因此,蜂窝梁的研究越来越多,应用也逐渐广泛。由于蜂窝梁腹板存在孔洞,使得其承载能力分析与实腹梁差异较大,蜂窝梁的受力分析需要考虑更多的因素,如腹板开孔尺寸和焊接质量等。目前,对于蜂窝梁的研究主要集中在强度、刚度以及整体稳定性方面,腹板局部稳定性的研究鉴于开孔形式各异、理论推导复杂,目前并无对应的理论解。已有的研究主要在单一受力状态下分析蜂窝梁腹板的屈曲问题,而这些研究与蜂窝梁腹板实际受力状态存在一定的差异。本文首先介绍了国内外蜂窝梁的研究现状,简要阐述了板的屈曲理论和稳定分析的常用方法。然后,依据薄板稳定理论,取蜂窝梁腹板为研究对象,假定蜂窝梁腹板约束条件为四边简支,利用有限元软件ANSYS建立了大量的开孔腹板模型并单独对其进行了纯弯、纯剪状态下的特征值屈曲分析,研究了不同影响因素下的蜂窝梁腹板在对应受力状态下的屈曲模式和屈曲应力的变化规律。通过参考实腹板弯曲屈曲系数公式和剪切屈曲系数公式,利用有限元分析得出的临界荷载,反算出相应的开孔腹板屈曲系数,通过数值分析软件MATLAB拟合出了开孔腹板在纯弯、纯剪状态下的屈曲系数公式,验证了公式的准确性,并采用嵌固系数来考虑不同受力状态下蜂窝梁翼缘对腹板的约束作用。再次,本文在蜂窝梁腹板单一受力状态分析的基础上,进一步研究了弯剪共同作用下两种较典型孔高比的蜂窝梁腹板弹性屈曲问题,提出了两组适用于蜂窝梁腹板在弯剪共同作用下的屈曲临界条件。最后,本文通过有限元软件对具体蜂窝梁进行弹性屈曲分析,总结了横向荷载作用下蜂窝梁在考虑不同孔高比、孔洞数、厚度以及横向加劲肋设置情况下,其腹板的屈曲模式与临界荷载变化规律。
[Abstract]:Honeycomb beam is a kind of beam-hole beam which is dislocated and welded by I-shaped beam on the web or directly cut into different types of holes. The main opening forms are circular hexagonal and octagonal. Honeycomb beams have many advantages over solid web beams, such as high flexural stiffness, high section modulus, good economic effect, easy to configure pipeline facilities and beautiful components, and so on. Therefore, the research of honeycomb beam is more and more, the application is also widespread gradually. Due to the existence of holes in the webs of honeycomb beams, the load capacity analysis of honeycomb beams is different from that of full web beams, and more factors need to be considered in the analysis of beehive beams, such as the size of web openings and welding quality. At present, the research of honeycomb beam is mainly focused on strength, stiffness and global stability. The study of local stability of web plate has no corresponding theoretical solution in view of the different orifice forms and complicated theoretical derivation. The existing researches mainly analyze the buckling problem of the web of honeycomb beam under a single stress state, but these researches are different from the actual stress state of the web of honeycomb beam. In this paper, the research status of honeycomb beams at home and abroad is introduced, and the buckling theory and stability analysis methods are briefly described. Then, according to the theory of thin plate stability, taking the web of honeycomb beam as the research object, assuming that the constraint condition of the web of honeycomb beam is simply supported on four sides, a large number of open-hole web models are established by using the finite element software ANSYS, and the pure bending of the web plate is carried out separately. The buckling analysis of eigenvalue under pure shear state is carried out, and the buckling mode and buckling stress of web plate of honeycomb beam under different influence factors are studied. By referring to the formula of bending buckling coefficient and shear buckling coefficient of real web, using the critical load obtained by finite element analysis, the corresponding buckling coefficient of open web is calculated, and the pure bending of open web is obtained by numerical analysis software MATLAB. The formula of buckling coefficient under pure shear state verifies the accuracy of the formula and uses the embedded coefficient to consider the constraint of the flange of honeycomb beam on the web under different loading conditions. Thirdly, on the basis of the analysis of the single stress state of the web of honeycomb beam, the elastic buckling problem of the web plate of honeycomb beam under the action of bending and shear is further studied, and the elastic buckling of the web plate of the honeycomb beam with typical ratio of hole to height is studied. Two sets of critical buckling conditions for web plate of honeycomb beam under the action of bending and shear are presented. Finally, the elastic buckling analysis of the concrete honeycomb beam is carried out by finite element software, and the effect of transverse load on the honeycomb beam is summarized under the consideration of different hole height ratio, hole number, thickness and transverse stiffening rib setting. The buckling mode and critical load variation of the web.
【学位授予单位】：西南石油大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TU391

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