大跨人行悬索桥非线性静风稳定性分析-论文.pdf

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1、振动与冲击第33卷第14期JOURNALOFVIBRAT1ONANDSHOCKVo1．33No．142Ol4大跨人行悬索桥非线性静风稳定性分析薛晓锋，管青海，胡兆同，李加武，刘健新(1．长安大学风洞实验室，西安710064；2．长安大学公路学院旧桥检测与加固技术交通行业重点试验室，西安710064)摘要：基于风洞试验所测加劲梁静力三分力系数，在综合考虑静风荷载非线性、结构几何非线性基础上，采用双重迭代计算分析方法对主跨420m大跨窄人行悬索桥进行静风稳定性全过程分析。结果表明，结构变形随风速变化呈明显非线性，静风失稳形态弯曲扭转空间耦合变形特征显著；较公路桥大跨人行悬索桥主缆提供的扭转刚

2、度比重更大，跟踪两主缆跨中应力随风速变化情况可定义静风失稳临界风速及与分析静风失稳原因；非零初始风攻角会降低静风失稳临界风速；中央扣及抗风缆均能提高静风失稳临界风速。施加中央扣措施，失稳形态为主梁结构弯扭失稳；施加抗风缆措施，失稳形态为抗风拉索、抗风缆应力松弛导致局部结构失稳。该研究可为大跨窄桥静风稳定性能及提高静风稳定性提供科学依据及参考。关键词：桥梁工程；人行悬索桥；数值计算方法；静风稳定性；几何非线性；静风荷载非线性中图分类号：U448．25文献标志码：ADOI：10．13465／j．cnki．iVS．2014．14．020Nonlinearaerostaticstabilitya

3、nalysisofalong-spansuspensionpedestrianbridge晒Xiao-feng，GⅣQing—hai，Zhao．tong，LIJia—wu，Jian—xin，(1．SchoolofHighway，Chang’anUniversity，Xi’an710064，China；2．KeyLaboratoryofMinistryofCommunicationsforBridgeDetection＆ReinforcementTechnology．SchoolofHighway，Chang'anUniversity，Xi’an710064，China)Abstract：

4、Thenonlinearaerostaticstabilityofa420m—main·spansuspensionpedestrianbridgewasanalysednumerically．Basedonaerostaticcoeficientsofthemaingirdermeasuredinwindtunneltests，nonlinearinfluencescausedbythestructureandaerostaticloadwereanalysedbyusingincrementaldoubleiterationmethod．Theresultsconcludeasfol

5、lows：thestructuredeformationvaryingwithwindspeedshowsobviousnonlinearity，andtheaerostaticinstabilitymodeisofthecharacteristicofspacedeformationofbending-twistingcouplingmode；comparingwiththehighwaybridge，thetorsionalstiffnessofthebridgeduetomaincablesaccountsforagreaterproportionofthestiffnessoft

6、helong—spansuspensionpedestrianbridge．Thecriticalwindvelocityandthereasonofaerostaticinstabilitycanbegotbytracingthestressinthemaincablewiththevariationofwindspeed；nonzeroinitialwindattackanglecanreducethecriticalwindspeed；centralbucklesandanti—windcablescarlraisethecriticalwindspeed．Theaerostati

7、cinstabilitymodeaftertheinstallationofcentralbucklesisthebending—twistingcouplingmodeofmaingirder，andtheaerostaticinstabilitymodeafteraddingthemeasureofanti·windcablesisthelocalstructuralbucklingduetothewindcablesandha