【摘要】 为获得碳纤维复合材料(CFRP)索斜拉试验桥的动力特性试验结果与理论值的差异,并比较CFRP索与钢索斜拉桥的动力特性和地震响应值,采用脉动法对CFRP索试验桥进行现场模态试验,联合采用峰值拾取法和互功率谱法识别模态参数,并将测试结果与有限元计算值进行对比;同时根据等轴向刚度准则进行CFRP索与钢索的替换,对不同配索模型分别进行了动力特性和地震响应分析。分析结果表明:试验桥的实测结果与计算值接近,振型吻合良好,前3阶自振频率最大差值仅为7.9%;因试验桥整体刚度大,CFRP索斜拉桥较钢索的优势仅部分体现,自振频率最大提升值为0.2%,地震作用下塔底轴力和弯矩峰值分别减小了0.11%和0.16%。更多还原

【Abstract】 In order to obtain the differences between the testing results and the theoretical values of dynamic characteristics of the testing cable-stayed bridge with CFRP(carbon fiber reinforced plastics) cables,and to compare dynamic characteristics and seismic response values of the cable-stayed bridge with CFRP and steel cables,the pulsating method is used for the field modal test of the CFRP cable-stayed experimental bridge,and the peak picking method and cross-power spectral density method are made joint use to identify its modal parameters,then these parameters are compared with the values of calculating by finite element model.And on the basis of axial stiffness equivalent principle,the CFRP cables of the experimental bridge are replaced with steel cables.Following that,the analysis of dynamic characteristics and seismic response is adopted to the models with different cables.The conclusions show that: the measured results of the testing bridge are close to the calculated values,their mode shapes match well,the maximum difference of their former three natural frequencies is only 7.9%;due to the enormous global stiffness of the testing bridge,the advantages of the cable-stayed bridge with CFRP cables over that with steel cables are only partially embodied;the largest increase of the natural frequency is only 0.2%;under some seismic action,the axial force and the bending moment in the bottom of the tower are reduced 0.11% and 0.16%.3 tabs,9 figs,12 refs.更多还原