钢桥塔典型开孔板的力学性能及补强方法

发布时间：2018-06-02 04:53

本文选题：钢桥塔 + 开孔板　；参考：《上海交通大学》2014年硕士论文

【摘要】：钢桥塔在桥梁工程中应用越来越广泛，但由于构造、施工、检修、维护等需要，不可避免对其中某些受力板件进行开孔。钢板开孔将对其力学性能产生不可忽略的影响，必要时需要采取措施对板件进行补强。但是，已有研究对于钢桥塔开孔板件力学性能及其补强设计方法的可借鉴成果却非常少。本文针对钢桥塔中典型的长圆形通行孔和连续椭圆形过索孔，在以试验结果为验证的基础上，采取解析推导和有限元分析相结合，对两类典型开孔板件的应力集中系数和受压极限荷载进行研究，并进一步围绕孔洞补强方法进行对比分析。主要研究工作和结论如下：（1）查阅国内外相关文献，介绍钢桥塔的技术发展和典型开孔问题。总结国内外研究现状，并提出亟待解决的问题。（2）简述两类典型开孔板件的受压试验，并对有限元分析方法进行介绍。通过对比试验数据和有限元结果，验证有限元模型的准确性。（3）采用弹性力学方法和数值计算方法对开长圆孔和开任意多个椭圆孔无限大平面的孔边应力集中系数进行了解析推导，算例分析结果与有限元解吻合良好；进一步基于有限元数值分析对有限大板几何参数的影响进行研究，发现当板件长宽比大于某一临界值时，孔边应力基本不受其影响，但SCF值随开孔率的增大而始终呈现非线性增长趋势。通过在无限大平面计算结果的基础上引入板宽修正系数，拟合得到了两类有限大开孔板的SCF计算公式，可用于实际工程中的应力集中评估。（4）介绍开方孔板件极限荷载的解析求法，并结合算例分析其适用性。将长圆孔和椭圆孔等效成矩形孔，对两类开孔板件的弹塑性受压极限强度进行了解析推导，并讨论了该方法对钢桥塔开孔板的适用性。通过与有限元结果比较，确定了开长圆孔板和开椭圆孔板的合理塑性铰线位置，并针对长宽比较大的板件提出了等效长宽比及其取值公式。（5）基于有限元分析，开展补强肋几何参数对补强后开孔板受压极限强度的影响分析，并引入极限强度提高系数来表征和量化补强效果。在补强肋高厚比固定的情况下，随着补强肋厚度不断增大，极限强度提高系数与补强肋厚度基本呈线性关系，但当补强肋厚度增大至某一值之后，极限强度提高系数则不再随补强肋厚度增大而提高。最终通过数值拟合，，提出了补强开孔板极限强度提高系数的计算公式，可用于实际工程中的开孔板补强设计。（6）对本论文的研究成果和所得结论进行总结，并对进一步研究内容提出展望。
[Abstract]:Steel bridge towers are more and more widely used in bridge engineering, but due to the need of structure, construction, overhaul and maintenance, it is inevitable to open some of them. The open hole of steel plate will have an important effect on the mechanical properties of steel plate. If necessary, measures should be taken to strengthen the plate. However, few studies have been done on the mechanical properties and reinforcement design of steel bridge tower. In this paper, based on the test results, the typical oblong circular passage holes and continuous elliptical cable passing holes in the steel bridge tower are combined with analytical derivation and finite element analysis. The stress concentration factor and compressive limit load of two kinds of typical perforated plates are studied, and the comparative analysis is carried out around the reinforcement method of holes. The main research and conclusions are as follows: The technical development and typical hole opening of steel bridge tower are introduced by consulting relevant documents at home and abroad. The present situation of domestic and international research is summarized, and the problems to be solved are put forward. The compression test of two kinds of typical perforated plate is briefly described, and the finite element analysis method is introduced. The accuracy of the finite element model is verified by comparing the experimental data with the finite element results. 3) the stress concentration factors of the infinite plane with long circular holes and any number of elliptical holes are analytically deduced by means of elastic mechanics method and numerical method. The results of the numerical examples are in good agreement with the finite element solution. The effect of finite element numerical analysis on the geometric parameters of finite plate is further studied. It is found that when the aspect ratio of plate is greater than a certain critical value, the hole edge stress is almost unaffected by the finite element method. However, with the increase of the open porosity, the SCF value always shows a nonlinear growth trend. By introducing the plate width correction coefficient on the basis of the results of infinite plane calculation, the SCF formulas for two kinds of finite perforated plates are obtained, which can be used to evaluate the stress concentration in practical engineering. In this paper, the analytical method of ultimate load of plate with square hole is introduced, and its applicability is analyzed with an example. The long circular and elliptical holes are equivalent to rectangular holes, and the ultimate strength of elastic-plastic compression of two kinds of perforated plates is derived, and the applicability of this method to the perforated plates of steel bridge tower is discussed. By comparing with the results of finite element method, the reasonable position of plastic hinges for long circular and elliptical perforated plates is determined, and the equivalent aspect ratio and its value formula are put forward for the plates with large length and width. 5) based on the finite element analysis, the influence of geometric parameters of reinforced ribs on the compressive ultimate strength of perforated plates after reinforcement is analyzed, and the enhancement coefficient of ultimate strength is introduced to characterize and quantify the reinforcement effect. When the ratio of reinforcement rib height to thickness is fixed, with the increasing of reinforcement rib thickness, the coefficient of ultimate strength improvement is basically linear with the reinforcement rib thickness, but when the reinforcement rib thickness increases to a certain value, The increasing coefficient of ultimate strength no longer increases with the thickness of reinforcing rib. Finally, through numerical fitting, a formula for calculating the increasing coefficient of the ultimate strength of reinforced perforated plate is proposed, which can be used in the reinforcement design of the perforated plate in practical engineering. 6) summarize the research results and conclusions of this paper, and put forward the prospect of further research.
【学位授予单位】：上海交通大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U441;U443.38

【参考文献】