CFRP索和钢索斜拉桥地震响应分析与抗震验算

为了研究碳纤维增强复合材料（CFRP）索和钢索斜拉桥在地震响应和抗震性能方面的差异，以苏通长江公路大桥为参考建立了有限元动力学模型。采用等轴向刚度准则进行钢索和CFRP索的替换，利用时程分析法比较了不同索斜拉桥的地震响应值，并进行了抗震验算和评价。结果表明：相对钢索斜拉桥，CFRP索斜拉桥的自振频率有明显提高，位移和内力地震响应值减小，响应衰减较快，且抗震性能优势明显，其原因是CFRP索斜拉桥自重轻、索桥耦合振动的概率小、索的材料阻尼大等；所得结论可为CFRP索在大跨斜拉桥中的应用提供参考。

Seismic Response Analysis and Seismic Resistance Checking of Cable-stayed Bridges with CFRP Cables and Steel Cables

In order to study the differences in seismic response and seismic resistance capacity of cable-stayed bridge with carbon fiber reinforced plastics （CFRP） cables and steel cables, the finite element dynamics model was established by taking Sutong Yangtze River Highway Bridge as a reference. The CFRP cables were replaced with steel cables using the equivalent axial stiffness principle. The time history analysis method was used to analyze and compare the seismic response values of cable-stayed bridges with different cables, and checking and evaluation of their seismic resistance capacity were also done. Results show that the seismic response values of internal force and displacement of the bridge with CFRP cables are smaller, the attenuation of its seismic response is faster, its seismic resistance capacity is much better than the bridge with steel cables, besides the natural frequencies increased obviously. The reasons in above include that the self-weight of the bridge with CFRP cables is lighter, the probability of coupling vibration between bridge and CFRP cables is smaller, and the material damping of the CFRP cable is larger, and so on. These conclusions may offer references for applications of CFRP cables in long-span cable-stayed bridge.