【作者】 孙胜江；

【导师】 李子青；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2013， 博士

【摘要】 在新世纪，土木工程结构，特别是桥梁结构和房屋建筑结构的安全性和耐久性日益得到重视，结构材料受到了新的挑战。具有轻质、高强、耐腐蚀、耐疲劳等优良性能的碳纤维增强非金属聚合物复合材料（CFRP），引起了土木工程界的广泛重视和兴趣，相关的研究和应用得到迅速开展并不断深入。将CFRP用作悬索桥主缆能充分发挥材料性能优势，一方面，大幅度减轻主缆自重，提高悬索桥承载效率，进而增大悬索桥的极限跨径；另一方面，解决钢主缆的腐蚀问题，特别是位于海洋等恶劣环境条件下的钢主缆极易腐蚀；再次，因主缆自重的大幅减轻，可以采用体积更小的锚碇和索塔，从而节省材料，并方便施工。由于世界上当前尚无CFRP缆索悬索桥建成的先例，相关文献也非常少，因此本文结合国家自然科学基金资助项目－“碳纤维复合材料缆索承重桥力学行为分析与优化设计法研究”（50908016），围绕CFRP缆索悬索桥这一主题，开展了一系列的科研工作，现将本文的主要研究成果和结论概括如下：1、CFRP缆索悬索桥成桥状态计算作为准确分析悬索桥静力、动力性能的基础，本文系统地研究了悬索桥主缆线形和内力的计算方法。分别建立了单索和分段悬链线索的线形和内力计算解析公式，同时提出缆索设计参数的迭代求解方法，并编制了相应的计算程序。研究了主缆与鞍槽切点坐标的计算方法，推导了主缆与鞍槽间的接触内力及鞍槽内主缆成桥长度、无应力长度的计算公式，并探讨了CFRP主缆对索鞍的设计要求。2、超大跨CFRP缆索悬索桥静力性能分析独立推导了悬索桥的极限跨径、承载效率、主缆面积、主缆自重应力等的解析计算式，并对两种缆索悬索桥的上述参数进行了计算和比较，证实了CFRP缆悬索桥在静力性能方面的优势。探索性设计了主跨分别为2000m、3000m的钢缆悬索桥和CFRP缆悬索桥以及主跨为5000mCFRP缆悬索桥，并分析和比较两者在恒载、汽车荷载、温度作用下的静力性能，得出了若干重要结论，为工程设计提供了科学依据。3、超大跨CFRP缆索悬索桥动力性能分析基于悬索桥基频解析估算公式，定性地研究了CFRP缆悬索桥的主要自振特性，结果表明，CFRP缆悬索桥的扭弯频率比大于钢缆悬索桥的相应值，对提高抗风稳定性有利。基于静力分析所建立的模型，采用有限元法分析和比较超大跨度CFRP缆悬索桥和钢缆悬索桥的动力特性；通过分析主要设计参数对CFRP缆悬索桥动力性能的影响，提出了提高CFRP缆悬索桥空气静力稳定性的措施，为结构的优化设计提供理论基础。4、超大跨CFRP缆索悬索桥静风稳定性研究根据流体力学的研究手段及控制方程，建立了加劲梁断面气动特性的数值模拟方法，分别利用FEA和FLUENT提取了静力三分力系数，两者吻合较好，表明计算结果可信；运用CFD方法研究了采取边缘风嘴气动措施后各种主梁断面的气动特性，并给出本文设计中比较合理的断面型式，为加劲梁断面的优化设计提供科学依据。应用桥梁结构三维非线性空气静力分析方法，首次分析了CFRP缆悬索桥在静风荷载作用下的稳定性和变形特征，并与钢缆悬索桥进行比较，分析结果表明，CFRP缆悬索桥的静风稳定临界风速略小于钢缆索，与经验公式计算结果一致。首次分析了矢跨比、加劲梁约束条件、缆索体系等对CFRP缆悬索桥静风稳定性的影响，并据此提出了提高CFRP缆悬索桥抗风稳定性的若干措施。5、粘结型锚具的受力分析提出了CFRP粘结型直筒式锚具极限承载力的解析计算方法；设计了一种直筒+内锥式锚具；建立了CFRP粘结型锚具的有限元分析方法并分析了其受力全过程；首次分析了粘结胶体的弹性模量和厚度、锚具长度、内锥角度等对CFRP粘结型锚具受力性能的影响，为CFRP锚具的优化提供科学依据。更多还原

【Abstract】 In the new century, the security and durability of civil engineering structures, such asbridge structures and building structures are considered increasingly and structural materialsare put forward new challenges. For its good performances, such as light weight, highstrength, good corrosion resistance and fatigue resistance, Carbon Fiber Reinforced Polymer(CFRP) has caught the attention and interest of the civil engineering realm, and it has beenresearched and applied rapidly. Used as main cables of suspension Bridges, its advantages canbe exerted fully. On the one hand, the deadweight of main cables can be greatly reduced, thecarrying efficiency can be improved, thus the ultimate span of suspension bridges can beincreased; On the other hand, the problem of corrosion of steel main cables can be solved,especially under severe environment conditions, such as the ocean environment, steel maincables are very easy to corrosion; Again, as the weight of main cable sharply reduces, asmaller anchorage and tower can be used, so materials can be saved and construction isconvenient. Up to date, there is no precedent of suspension bridge with CFRP cable is built,related literature is very less, so a series of scientific research work around the theme ofsuspension bridge with CFRP cable has been carried out in this paper, combining with theNNSF of China-" Mechanical behavior analysis and optimization design method research ofcable bearing bridges with CFRP "(50908016). The main research results and conclusions aresummarized as follows:1、Calculating of completed state of suspension bridge with CFRP cableAs the basis of accurate analysis of static and dynamic performance of suspension bridges,the method of calculating the line shape and internal force of main cables is studiedsystematically in this paper. The calculation formulas of the line shape and internal force ofthe single cable and the segmental catenary cable are established respectively. Iterationmethod of the design parameter of the cables is put forward and a corresponding calculatingprogram is compiled.The calculation method of tangent point coordinates of main cable and saddle groove isstudied, the calculation formulas of interactive forces between main and saddle groove and the unstressed length of the main cable inside the saddle groove are deduced. Then the designrequirements of CFRP main cable saddle are discussed.2、Static performances analysis of super-span suspension bridge with CFRP cableThe analytic calculation formulas of the ultimate span, carrying efficiency，main cable areaand deadweight stress of suspension bridges are deduced independently. The aboveparameters of two kinds of cable suspension bridges are calculated and compared. It indicatesthat CFRP cables suspension bridges have more advantages compared with steel cablessuspension bridges.The2000m-span,3000m-span suspension bridges with CFRP cables and steel cables and5000m-span suspension bridge with CFRP cables are designed deploringly. The staticperformances of the two kinds of main cables suspension bridges under the action of deadload, vehicle load and temperature are analyzed and compared using of the finite-elementmethod. Some important conclusions are obtained, which can provide scientific proofs fordesign.3、Dynamic performance analysis of super-span suspension bridge with CFRP cableBased on the analytic estimation formulas of fundamental frequency of suspension bridges,the natural vibration characteristics of CFRP cable suspension bridge is studied qualitatively,the results show that frequency ratio of torsional and bending of CFRP cable suspensionbridge is greater than the corresponding values of steel cable suspension bridge, which is goodfor improving the wind stability.Based on the models established for aforementioned static analysis, dynamic characteristicsof super-span CFRP cable suspension bridge and steel cable suspension bridge are analyzedand compared using of the finite element method. The general rules of dynamiccharacteristics of the super-span CFRP cable suspension bridge is summarized; Through theanalysis of influence of several main design parameters on the dynamic characteristics of theCFRP cable suspension bridge, the measures for improving the aerodynamic stability ofCFRP cable suspension bridge are put forward, which provides a theoretical basis forstructure optimization design.4、The study on aerostatic stability of suspension bridges with CFRP Cables According to the research techniques and the control equations of fluid mechanics, thenumerical simulation method of the aerodynamic characteristics of the stiffening girdersection is established. The static three component force coefficients are extracted respectivelyusing the FEA and the FLUENT software; Both are in good agreement, which indicates thatthe calculation results are credible. The aerodynamic characteristics of several kinds of maingirder section with different aerodynamic measures of edge tuyere are researched for the firsttime using CFD method. A reasonable cross section type is suggested in this paper, whichprovides a scientific basis for optimization design of the stiffening girder section.The stability and deformation characteristics of the two kinds of cable suspension bridgeunder calm wind load are analyzed and compared for the first time using bridge structurethree dimensional nonlinear aerostatic analysis methods. Analysis results show aerostaticinstability critical wind speeds of the CFRP cable suspension bridge is a little smaller thanthat of steel cable, which is consistent with calculation results from the empirical formula.The effects of rise-span ratio, constraint condition of stiffening girder and cable system，etcon the aerostatic stability of CFRP cable suspension bridge are analyzed for the first time,accordingly measures of improving wind resistance stability CFRP cable suspension bridgeare put forward.5、Mechanics Analysis of the adhesive Anchorage with CFRPThe analytic calculation method of the ultimate capacity of straight pipe anchorage isproposed. A kind of straight pipe inner cone anchorage is designed. Finite element analysismethod of CFRP adhesive anchor is established and the Loading process of it is analyzed bythis method.The effect of elastic modulus, thickness of the adhesive colloid, anchorage length andinner cone angle on the mechanics performance of anchorage are analyzed for the first time,which will provide a scientific basis for optimization of CFRP anchor.更多还原