索梁结构应急桥抖振响应分析
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摘要
针对新型索梁结构应急桥结构刚度小、质量轻的特点,开展脉动风荷载作用下应急桥的抖振响应研究。利用ANSYS软件建立桥梁结构模型,分析其动力特性。采用谐波合成法模拟脉动风场,基于准定常抖振分析模型计算了主梁节点的静风力、抖振力。运用APDL编制程序分析轻型索梁结构应急桥的抖振响应,分析气动导纳函数和自激气动力对桥梁结构抖振响应的影响,并对提出的斜拉索抗风缆方案进行抖振响应计算。计算结果表明:索梁结构应急桥抖振横向位移远大于竖向位移,说明结构侧向刚度较弱;跨中主缆应力对风速变化更为敏感,而吊杆应力波动较小;索梁结构应急桥跨中横向位移主要受主梁正对称侧弯振型的影响;竖向位移主要受主梁一阶正对称竖弯振型的影响;扭转角主要受主梁一阶正对称扭转振型的影响;不考虑气动导纳函数会使索梁结构应急桥抖振响应计算结果偏大,气动自激力对结构抖振响应影响较小。与原方案相比,斜拉索抗风缆方案能够极大地降低横向抖振位移,对竖向位移和扭转角影响较小。
Aiming at the characteristics of small stiffness and light weight of emergency bridge with new-type cablegirder structure,buffeting response of emergency bridge under f luctuating wind load was studied.The emergency bridge model was established by using ANSYS software to analysis the dynamic characteristics.The weighted amplitude wave superposition(WAWS) method was used to simulate the f luctuating wind f ield,and the static wind force and buffeting force of the main girder joint were calculated based on the quasi-steady buffeting analysis model.The buffeting response of emergency bridge with light cable-girder structure was analyzed by APDL programming.The inf luences of aerodynamic admittance function and self-excited aerodynamic force on buffeting response of bridge structure were analyzed.The buffeting response of cable-stayed wind-resistant cable scheme was calculated.The calculation results show that the buffeting transverse displacement of emergency bridge with cable-girder structure is much larger than that of vertical displacement,which indicates that the transverse stiffness of the structure is weak.The stress of main cable in midspan is more sensitive to the change of wind speed,while the stress f luctuation of suspender is smaller.The transverse displacement in the midspan of emergency bridge with cable-girder structure is mainly affected by the positive symmetrical lateral bending mode of the main girder,the vertical displacement is mainly affected by the f irst-order positive symmetrical vertical bending mode of the main girder,and the torsion angle is mainly affected by the f irst-order positive symmetrical torsional mode of the main girder.Without considering the aerodynamic admittance function,the results of buffeting response of emergency bridge with cable-girder structure will be larger,and the inf luence of aerodynamic self-excitation force on buffeting response of structure will be smaller.Compared with the original scheme,the wind-resistant cable scheme can greatly reduce the transverse buffeting displacement,and has less inf luence on the vertical displacement and torsion angle.
Aiming at the characteristics of small stiffness and light weight of emergency bridge with new-type cablegirder structure,buffeting response of emergency bridge under f luctuating wind load was studied.The emergency bridge model was established by using ANSYS software to analysis the dynamic characteristics.The weighted amplitude wave superposition(WAWS) method was used to simulate the f luctuating wind f ield,and the static wind force and buffeting force of the main girder joint were calculated based on the quasi-steady buffeting analysis model.The buffeting response of emergency bridge with light cable-girder structure was analyzed by APDL programming.The inf luences of aerodynamic admittance function and self-excited aerodynamic force on buffeting response of bridge structure were analyzed.The buffeting response of cable-stayed wind-resistant cable scheme was calculated.The calculation results show that the buffeting transverse displacement of emergency bridge with cable-girder structure is much larger than that of vertical displacement,which indicates that the transverse stiffness of the structure is weak.The stress of main cable in midspan is more sensitive to the change of wind speed,while the stress f luctuation of suspender is smaller.The transverse displacement in the midspan of emergency bridge with cable-girder structure is mainly affected by the positive symmetrical lateral bending mode of the main girder,the vertical displacement is mainly affected by the f irst-order positive symmetrical vertical bending mode of the main girder,and the torsion angle is mainly affected by the f irst-order positive symmetrical torsional mode of the main girder.Without considering the aerodynamic admittance function,the results of buffeting response of emergency bridge with cable-girder structure will be larger,and the inf luence of aerodynamic self-excitation force on buffeting response of structure will be smaller.Compared with the original scheme,the wind-resistant cable scheme can greatly reduce the transverse buffeting displacement,and has less inf luence on the vertical displacement and torsion angle.
引文
[1]曹映泓,项海帆,周颖.大跨度桥梁颤振和抖振统一时程分析[J].土木工程学报,2000,33(5):57-62.
[2]张志田.大跨度桥梁非线性抖振及其对抗风稳定性影响的研究[D].上海:同济大学,2004.
[3]刘春华.大跨度桥梁抖振响应的非线性时程分析[D].上海:同济大学,1995.
[4]TAO T,WANG H,WU T. Parametric Study on Buffeting Performance of a Long-span Triple-tower Suspension Bridge[J].Structure and Infrastructure Engineering,2018,14(3):1-19.
[5]HUANG H,LI M. Flutter and Buffeting Analysis in Time Domain for Suspension Bridge in Operation and Erection Stage[C]//Japan Association for Wind Engineering and International Association for Wind Engineering. The Fourth International Symposium on Computatinal Wind Engineering(CWE2006).Yokohama:Tokyo Polytechnic University Press,2006:781-784.
[6]刘孝辉,左太辉,何旭辉,等.大跨度公轨两用钢桁梁悬索桥抖振响应研究[J].公路交通技术,2017,33(6):49-54.
[7]李飞,刘多特.大跨度预应力混凝土连续刚构桥时域抖振分析[J].铁道建筑,2018,58(3):5-9.
[8]陈代海,李整,张超.大跨度窄桥面钢桁架悬索桥抖振影响因素分析[J].铁道建筑,2016,56(11):10-14.
[9]夏培华,朱浩.山区钢桁梁斜拉桥施工期抖振时域分析研究[J].中国港湾建设,2017(11):104-107.
[10]董锐,葛耀君,杨詠昕,等.基于独立振型的大跨度桥梁风致抖振响应分析[J].长安大学学报(自然科学版),2016,36(3):56-63.
[11]张贤文.大跨度钢桁架拱桥抖振数值仿真分析[J].湖南交通科技,2016,42(3):98-101.
[12]中华人民共和国交通部.公路桥梁抗风设计规范:JTG/T3360-01—2018[S].北京:人民交通出版社,2018.
[2]张志田.大跨度桥梁非线性抖振及其对抗风稳定性影响的研究[D].上海:同济大学,2004.
[3]刘春华.大跨度桥梁抖振响应的非线性时程分析[D].上海:同济大学,1995.
[4]TAO T,WANG H,WU T. Parametric Study on Buffeting Performance of a Long-span Triple-tower Suspension Bridge[J].Structure and Infrastructure Engineering,2018,14(3):1-19.
[5]HUANG H,LI M. Flutter and Buffeting Analysis in Time Domain for Suspension Bridge in Operation and Erection Stage[C]//Japan Association for Wind Engineering and International Association for Wind Engineering. The Fourth International Symposium on Computatinal Wind Engineering(CWE2006).Yokohama:Tokyo Polytechnic University Press,2006:781-784.
[6]刘孝辉,左太辉,何旭辉,等.大跨度公轨两用钢桁梁悬索桥抖振响应研究[J].公路交通技术,2017,33(6):49-54.
[7]李飞,刘多特.大跨度预应力混凝土连续刚构桥时域抖振分析[J].铁道建筑,2018,58(3):5-9.
[8]陈代海,李整,张超.大跨度窄桥面钢桁架悬索桥抖振影响因素分析[J].铁道建筑,2016,56(11):10-14.
[9]夏培华,朱浩.山区钢桁梁斜拉桥施工期抖振时域分析研究[J].中国港湾建设,2017(11):104-107.
[10]董锐,葛耀君,杨詠昕,等.基于独立振型的大跨度桥梁风致抖振响应分析[J].长安大学学报(自然科学版),2016,36(3):56-63.
[11]张贤文.大跨度钢桁架拱桥抖振数值仿真分析[J].湖南交通科技,2016,42(3):98-101.
[12]中华人民共和国交通部.公路桥梁抗风设计规范:JTG/T3360-01—2018[S].北京:人民交通出版社,2018.