大跨CFRP索斜拉桥的拉索锚固性能及风致振动研究

发布时间：2018-04-24 16:33

本文选题：CFRP索 + 锚固系统　；参考：《江苏大学》2015年博士论文

【摘要】：斜拉桥因其外形美观、跨越能力强、结构刚度大等突出优点而在大跨桥梁中受到青睐并广泛采用。拉索是斜拉桥的一个重要受力构件,传统钢拉索由于钢材的极限强度、承载效率以及耐腐蚀性等问题已成为制约斜拉桥跨径的重大因素。碳纤维增强塑料(Carbon Fiber Reinforced Polymer,简称CFRP)具有不锈蚀、无磁性、低松弛性、轻质高强、抗疲劳等优良特性,将CFRP索应用于预应力超大跨斜拉桥,具有较高的研究价值和广阔的应用前景。但是CFRP筋在纵、横向材性上有较大差异,若以CFRP索替代钢索,其锚固性能和锚具设计还存在尚未研究解决的问题。此外,相对于钢索,CFRP索具有质量轻、脆性大、弹性模量低等特点,在恶劣环境下,极易发生风致振动进而导致桥梁破坏。本文依托国家自然科学基金项目—“基于高性能材料CFRP索的超大跨桥梁原型设计与相关问题研究(No.51078170)”,以CFRP索的锚固系统性能和风致振动两个重要方面为研究内容,主要完成了以下工作：(1)对CFRP索锚固系统进行理论分析和试验研究。研究各类型CFRP筋(索)锚固系统性能的适用性,建立适用的理论计算模型,并通过试验检验理论计算模型的准确性。优化设计大吨位CFRP筋(索)锚具,提供设计和应用建议。(2)基于流固耦合理论研究了CFRP拉索的风致振动特性。基于流固耦合理论建立CFRP索结构瞬态响应的简化模型,并利用相关软件建立数值模型,研究分析强风作用下CFRP索多种工况时的抗风性能及瞬态动力学响应特点和规律,对比相同条件下钢拉索风致振动的差异性。(3)基于准定常假设研究CFRP拉索风-雨致振特征。推导建立斜拉索风-雨致振的简化分析模型和稳定性准则,利用数值分析模型,研究分析CFRP拉索风-雨致振特性,以及各参数对风-雨致振的影响,初步探索CFRP拉索在风-雨激励下的运动规律和机理及参数敏感性等问题。通过以上研究,优化了CFRP筋(索)的锚固系统,提出了大吨位锚具的设计建议；基于流固耦合理论推导了CFRP索在风作用下的简化模型,得到了CFRP索区别于钢索的风致振动瞬态特性及各种参数下风-雨致振的特征和运动规律,为CFRP索在缆索结构桥梁中的应用设计提供参考。
[Abstract]:Cable-stayed bridges are widely used in long-span bridges because of their outstanding advantages such as beautiful appearance, strong span ability and large structural stiffness. Cable is an important force member of cable-stayed bridge. Traditional steel cable has become a major factor restricting the span of cable-stayed bridge because of the limit strength, bearing efficiency and corrosion resistance of steel. Carbon Fiber Reinforced Polymer (CFRP) with carbon fiber reinforced plastics (CFRP) has the advantages of non-rust, non-magnetism, low relaxation, lightweight and high strength, fatigue resistance and so on. The application of CFRP cable in prestressed super-span cable-stayed bridge has high research value and broad application prospect. However, there are great differences in the longitudinal and transverse properties of CFRP bars. If CFRP cables are used instead of steel cables, the anchoring performance and the design of anchors are still unsolved. In addition, compared with the steel cable CFRP rigging, it has the characteristics of light weight, large brittleness and low elastic modulus, so it is easy to occur wind-induced vibration and lead to bridge failure in bad environment. Based on the project of National Natural Science Foundation of China-"prototype Design and related problems of Super large Span Bridge based on High-Performance material CFRP Cable (No.51078170)", this paper focuses on two important aspects of anchoring system performance and wind-induced vibration of CFRP cables. The main work is as follows: 1) theoretical analysis and experimental study on CFRP cable Anchorage system. The applicability of various types of CFRP bars (cables) Anchorage system is studied and the applicable theoretical calculation model is established. The accuracy of the theoretical calculation model is verified by experiments. Optimization design of large-tonnage CFRP tendons (cables) anchors and suggestions for design and application. (2) based on the fluid-solid coupling theory, the wind-induced vibration characteristics of CFRP cables are studied. Based on the fluid-solid coupling theory, the simplified model of transient response of CFRP cable structure is established, and the numerical model is established by using related software. The characteristics and laws of wind resistance and transient dynamic response of CFRP cable under various conditions under strong wind are studied and analyzed. The differences of wind-induced vibration of steel cables under the same conditions are compared. (3) based on quasi-steady hypothesis, the wind-rain vibration characteristics of CFRP cables are studied. The simplified analysis model and stability criterion of wind-rain vibration induced by stay cable are derived and established. By using numerical analysis model, the wind-rain vibration characteristics of CFRP cable and the influence of various parameters on wind-rain vibration are studied. The motion law, mechanism and parameter sensitivity of CFRP cables under wind-rain excitation were preliminarily explored. Through the above research, the anchoring system of CFRP tendons (cables) is optimized, and the design suggestions for large-tonnage anchors are put forward, and the simplified model of CFRP cables under wind action is derived based on the fluid-solid coupling theory. The transient characteristics of wind-induced vibration of CFRP cables different from those of steel cables and the characteristics and motion laws of wind-rain induced vibration under various parameters are obtained, which provides a reference for the application and design of CFRP cables in cable-structure bridges.
【学位授予单位】：江苏大学
【学位级别】：博士
【学位授予年份】：2015
【分类号】：U448.27

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