Abstract：A truss stiffening girder suspension bridge with a main span of 1100m was taken as the engineering background. The wind tunnel tests of the spring-suspend section model were conducted to study the characteristics and mechanism of the post flutter. First, the structural parameters of the section model test system with the truss girder were tested. Then, the flutter tests of the truss girder section model were carried out at different wind attack angles. Finally, the mechanism of limit cycle oscillation (LCO) for the truss girder section model was discussed in the view of nonlinear damping. The results show that there are obvious damping nonlinearity and slight stiffness in the section model test system with the truss girder at large amplitudes. The LCO of the truss girder section model is observed at each wind attack angle. Wind attack angle has significant effects on the critical flutter wind speed and the slopes of the amplitude versus wind speed. The LCO of the truss girder section model is characterized by a coupled bending and torsion vibration, and the bending-torsion coupling level increases as the amplitude increases. For the wind tunnel tests of the truss girder section model, structural damping nonlinearity is a favorable factor for the stability of LCO, while aerodynamic damping nonlinearity has different effects at different wind attack angles.
张瑞林1,2，杨鸿波3，刘志文1,2，杨健3，陈政清1,2. 桁架加劲梁悬索桥后颤振特性节段模型试验研究[J]. 振动与冲击, 2022, 41(5): 1-8.
ZHANG Ruilin1,2, YANG Hongbo3, LIU Zhiwen1,2, YANG Jian3, CHEN Zhengqing1,2. Segmental model tests for post flutter characteristics of truss-stiffening girder suspension bridge. JOURNAL OF VIBRATION AND SHOCK, 2022, 41(5): 1-8.
[1] Scanlan R H, Tomko J. Airfoil and bridge deck flutter derivatives. Journal of Enginnering Mechanics. ASCE 1971, 97 (6), 1717–1737.
[2] 项海帆. 现代桥梁抗风理论与实践[M]. 北京：人民交通出版社, 2005: 1-6.
XIANG H F. Theory and practice of wind resistance of modern bridges [M]. Beijing: China Communications Press, 2005:1-6.
[3] AMANDOLESE X, MICHELIN S, CHOQUEL M. Low speed flutter and limit cycle oscillations of a tow-degree-freedom flat plate in wind tunnel[J].Journal of Fluid and Structures, 2013,43: 245-255.
[4] 朱乐东，高广中. 典型桥梁断面软颤振现象及影响[J]. 同济大学学报：自然科学版，2015, 43(9):1289-1382.
ZHU Ledong, GAO Guang-zhong. Influential factors of soft fluyyer phenomenon for typical bridge deck sections[J]. Journal of Tongji University:Natural Science, 2015, 43(9): 1289-1382.
[5] ZHANG M, XU F, YING X. Experimental investations on the nonlinear torsional fluter of a bridge deck[J]. Journal of Bridge Engineering, 2017,22(8): 04017048.
[6] GAO G, ZHU L, HAN W, et al. Nonlinear post-flutter behavior and self-excited force model of a twin-side-girder bridge deck[J].Journal of Wind Enginnering and Industrial Aerodynamics, 2018,177: 227-241.
[7] YING X, XU F, ZHANG M, et al. Numerical explorations of the limit cycle flutter characteristics of a bridge deck[J].Journal of Wind Engineering and Industrial Aerodynamic, 2017,169: 30-38.
[8] TANG Y, HUA X, CHEN Z, et al. Experiment investigation of flutter characteristics of shallow Π section at post-critical regime[J].Journal of Fluid and Structures, 2019,88: 275-291.
[9] 伍波，王骑，廖海黎. 双层桥面桁架梁软颤振特性风洞试验研究[J]. 振动与冲击，2020, 39(1):191-198.
WU Bo, WANG Qi, LIAO Haili. Wind tunel tests for soft flutter characteristics of double-deck truss girder[J]. Journal of Vibration and Shock, 2020, 39(1): 191-198.
[10] 朱乐东，高广中. 双边肋桥梁断面软颤振非线性自激力模型[J]. 振动与冲击，2016, 35(21):29-35.
ZHU Le-dong, GAO Guang-zhong. A nonliear self-excited force model for soft flutter phenomenon of a twin-side-girder bridge section[J]. Journal of Vibration and Shock, 2016, 35(21): 29-35.
[11] ZHANG M J, XU F Y, ZHANG Z B, et al. Energy budget analysis and engineering modeling of post-flutter limit cycle oscillation of a bridge deck[J]. Journal of Wind Enginnering and Industrial Aerodynamics, 2019,188: 410-420.
[12] GAO G, ZHU L. Nonlinarity of mechanical damping and stiffness of a spring-suspended sectional model system for wind tunnel tests[J]. Journal of Sound and Vibration, 2015,355: 369-391.
[13] WU B, CHEN X, WANG Q. Characterization of vibration amplitude of nonlinear bridge flutter from section model test to full bridge estimation[J].Journal of Wind Enginnering and Industrial Aerodynamics, 2020,197: 104048.
[14] ZHANG Z. Multistage indicial functions and postflutter simulation of long-span bridges[J]. Journal of Bridge Engineering, 2018,23(4): 04018010.
[15] 吴长青，张志田，张伟峰. 考虑几何非线性的桥梁后颤振极限环特性[J]. 湖南大学学报, 2018, 45(5):1-10.
WU Changqing, ZHANG Zhitian, ZHANG Weifeng, et al. Limit cycle oscillation of bridge post-flutter with geometric nonlinearities[J]. Journal of Hunan University: Natural Sciences, 2018, 45(5): 1-10.
[16] 张宏杰，朱乐东. 附加风攻角对1400m斜拉桥颤振分析结果的影响[J].振动与冲击，2013, 32(17):95-99.
ZHANG Hong-jie, ZHU Le-dong. Influence of additional attack angle on flutter performence of a 1400m long cable stayed bridge[J]. Journal of Vibration and Shock, 2013, 32(17):95-99. (in Chinese)
[17] 中华人民共和国交通运输部. 公路桥梁抗风设计规范JTG/T 3360-01-2018[S]. 北京：人民交通出版社，2018.
[18] 杨詠昕，葛耀君，项海帆.平板断面扭弯耦合颤振机理研究[J]. 工程力学, 2006, 23(12):1-8.
YANG Yong-xin, GE Yao-jun, XIANG Hai-fan. Research on the coupled bending-torsional flutter mechanism for thin plat sections[J].Engineeing mechnaics, 2006, 23(12): 1-8. (in Chinese)
[19] 刘志文，谢普仁，陈政清，等.大跨度流线型箱梁悬索桥颤振稳定性气动优化[J]. 湖南大学学报, 2019, 46(3):1-9.
LIU Zhiwen, XIE Puren, CHEN Zhengqing, et al. Aerodynamic optimization of flutter stability for a long-span streamlined box girder suspension bridge [J]. Journal of Hunan University: Natural Sciences, 2019, 46(3): 1-9.
