超大跨径CFRP主缆悬索桥动力特性参数分析

摘要

In order to research the dynamic responses of a super-long span suspension bridge with CFRP cables,a super-long-span suspension bridge with CFRP (carbon-fibre reinforced plastic)cables and having a span of 3 500 m was designed by taking a strait as engineering background. Based on the ANSYS software,its dynamic responses and the effects of structural design parameters on the dynamic responses were analyzed. These structural design parameters are rise-span ratio,main cable safety factor,restraint systems of the stiffening girder and bridge tower stiffness. The research results show that torsional-bending frequency ratio increases proportionately with rise-span ratio,and the main cable safety factor has a little effect on the dynamic responses,and a long span decreases the effect of the restraint system of stiffening girder on the dynamic responses and increases the bending stiffness of bridge tower in the axial direction of bridge and the torsional stiffness are benefit to raise the vertical vibration fundamental frequency and torsional vibration fundamental frequency.%为了研究超大跨径碳纤维（CFRP）主缆悬索桥的动力性能，以某海峡为工程背景，设计了主跨3500 m的CFRP主缆悬索桥。基于ANSYS软件平台，分析了该CFRP主缆悬索桥的动力特性，探讨了矢跨比、主缆安全系数、加劲梁约束体系和桥塔刚度等主要结构参数对其动力特性的影响。研究结果表明：矢跨比越大，扭弯频率比越大；主缆安全系数对动力特性影响不大；随跨径增大，加劲梁约束体系对动力特性的影响减小；增大桥塔顺桥向弯曲刚度可以提高对称竖弯基频，增大桥塔抗扭刚度可提高扭转基频。