吊索材料对某大跨中承式铁路拱桥风致响应的影响研究

Study on the Effect of Hanger Material on Wind-induced Response of a Long-span Half-through Railway Arch Bridge

为研究钢吊索和碳纤维吊索对拱桥结构静动力性能的影响,以山区某大跨中承式铁路拱桥为研究对象,建立有限元分析模型开展非线性动力仿真分析,获取了主梁和吊索不同位置的振动响应,分析了吊索材料对拱桥构件风致响应的影响规律。结果表明:(1)基于等强替换的原则,将拱桥钢吊索更换为碳纤维吊索,主梁主导的振型频率增幅达3%~12%,吊索振动基频提升约27%;(2)与采用钢吊索相比,碳纤维吊索拱桥的主梁横桥向位移增大超50%,吊索自身的横桥向位移增大约60%,而主梁的竖向位移和吊索的顺桥向位移则大幅度减小;(3)不同材料吊索的风致应力幅差异不大,均接近3 MPa;(4)采用碳纤维吊索时,拱桥的风致响应频率相对集中,采用钢吊索时则较为发散,发生振动的可能性更高。

To study the effect of steel and carbon hanger on the static and dynamic performance of arch bridge structures,a long-span half-through railway arch bridge located in a mountainous area was taken as the research object.Finite element analysis models were established to conduct nonlinear dynamic simulation analysis.The vibration responses at different locations of the main girder and hangers were obtained and the effect of hanger materials on the wind-induced responses of arch bridge components was analyzed.The results indicate that:(1)Based on the principle of equal strength replacement,replacing the steel hangers of the arch bridge with carbon hangers can increase the dominant vibration mode frequency of the main girder by approximately 3%to 12%,and enhance the fundamental frequency of the hanger vibration by approximately 27%.(2)Compared to using steel hangers,the transverse displacement of the main girder increases by over 50%when carbon fiber hangers are adopted,and the transverse displacement of the hanger themselves increases by approximately 60%,while the vertical displacement of the main girder and the longitudinal displacement of the hangers are significantly reduced.(3)The wind-induced stress amplitudes of hangers made from different materials do not differ significantly,both approaching 3 MPa.(4)When carbon hangers are used,the wind-induced response frequency of the arch bridge is relatively concentrated,while when steel hangers are used,they are more dispersed,indicating a higher possibility of vibration occurrence.