应用CFRP索的缆索承重桥梁抗风稳定性研究

为了探讨CFRP索在缆索承重桥梁中应用的可能性,以缆索等轴向刚度为原则,基于润扬长江大桥和1400 m主跨斜拉桥设计方案,分别拟定了同跨径应用CFRP索的悬索桥和斜拉桥,并运用三维非线性空气动力稳定性分析方法进行了抗风稳定性分析。分析结果表明:缆索承重桥梁采用CFRP索后,由于结构自振频率特别是扭转频率的显著提高,其空气动力稳定性要好于钢索的缆索承重桥梁。因此从抗风稳定性角度而言,缆索承重桥梁采用CFRP索是可行的,缆索截面尺寸应采用等轴向刚度原则来确定。

A Study on Wind Stability of Cable-Supported Bridges Using CFRP Cables

To gain understanding of the applicability of carbon fiber reinforced polymer(CFRP) cable in cable-supported bridges,on the basis of the Runyang Yangtze River Bridge and the design scheme for cable-stayed bridge with 1 400 m main span,a suspension bridge with CFRP cables and a cable-stayed bridge with CFRP stay cables are schemed,in which the cable's cross-sectional area is determined by the principle of equivalent axial stiffness.Numerical investigations on the aerodynamic stability of the two bridges are conducted by 3D nonlinear aerodynamic stability analysis.The results show that as CFRP cables are used in cable-supported bridges,its aerodynamic stability is superior to that of the case using steel cables due to the great increase of the torsional frequency.Therefore as far as the wind stability is considered,the use of CFRP cables in cable-supported bridges is feasible,and the cable's cross-sectional area should be determined by the principle of equivalent axial stiffness.