辅助索对H型吊杆抖振控制分析

为研究辅助索对H形吊杆抖振控制的适用性,分别建立了安装辅助索前后单根H形吊杆有限元模型,采用时域分析法对不同风攻角和风速作用时吊杆应力状态进行数值计算。首先,采用谐波合成法生成脉动风场,获得H形吊杆的风速时程;其次,计算了H形吊杆关键节点的静风力、抖振力和自激力;最后,基于时域分析法,分析设置辅助索前后吊杆关键节点的轴向应力和应力幅变化。研究结果表明:H形吊杆的轴向应力在90°风攻角下最大;吊杆轴向应力增长幅度随风速增长而增大,并在风速超过10 m/s时急剧增大;安装辅助索可降低H形吊杆轴向应力约60%,降低应力幅超过50%。安装辅助索对H形吊杆抖振控制具有良好的减振效果和适用性。

Analysis on the Buffeting Control of H-section hanger by Auxiliary Cable

In order to study the applicability of auxiliary cables for buffeting control of H-section hanger, the finite element models of single H-section hanger before and after installation of auxiliary cables were established respectively. The stress state of hangers under different wind attack angles and wind velocities was numerically calculated by time domain analysis method. Firstly, the fluctuating wind field was generated by harmonic synthesis method, and the wind speed time history of H-section hanger was obtained. Secondly, the static wind force, buffeting force and self-exciting force of the key nodes of H-section hanger were calculated. Finally, based on the time domain analysis method, the changes of the axial stress and stress amplitude of the key nodes of H-section hanger before and after setting auxiliary cables were analyzed. The results show that the axial stress of the H-section hanger is the largest at 90 degrees wind attack angle; the increase range of the axial stress of the hanger increases with the increase of wind speed, and increases sharply when the wind speed exceeds 10 m/s; the installation of auxiliary cables can reduce the axial stress of the H-section hanger about 60% and the stress amplitude over 50%. It can be seen that the installation of auxiliary cables has good effect and applicability for buffeting control of H-section hangers.