半主动调谐质量阻尼器对随机人群荷载振动控制

Semi-Active Tuned Mass Dampers for Vibration Control of Random Crowd Load

摘要:

为提高人行桥的舒适度，提出了一种可变质量与阻尼的半主动调谐质量阻尼器（STMD）。该STMD不但能通过水泵和电磁阀等驱动装置实时调节质量以重调频率来适应人行桥动力特性的变化，而且能实时改变电涡流阻尼的磁导间距来调节阻尼系数以提高耗能效果。首先介绍了STMD变质量及变阻尼的算法及模型试验，然后进行基于人群激励概率性随机模型的案例分析。对比研究了无控结构、优化设计的被动TMD、变质量STMD、变阻尼STMD及变质量变阻尼STMD在随机协同人群荷载下的100次加速度响应，通过这100组加速度的最大值、均方根（RMS）值及最大1-s RMS值共3个舒适度评估指标的最大值、平均值和标准差，分析了不同TMD的减振效果及鲁棒性。研究结果表明，由于人群荷载和人体参数的随机性，结构的动力响应有较大的差异。整体而言，可同时变质量变阻尼的STMD具有最佳的减振效果，且其标准差也最小，即具有最好的鲁棒性。

Abstract:

To improve the serviceability of footbridge， a semi-active tuned mass damper（STMD） with variable mass and damping is proposed， which can not only adjust its own mass and frequency in real time to adapt to the dynamic characteristics of the footbridge through the water pump and electromagnetic valve， but also adjust its own damping coefficient in real time to improve the effect of energy dissipation through changing the air gap of eddy current damping. First， the variable mass and damping algorithm and model test of STMD are introduced. Then， a case study is conducted based on the probabilistic random model of crowd excitation. Afterwards， the 100 times acceleration response of the structure without control， with an optimized passive TMD， variable mass STMD， variable damping STMD and variable mass and damping STMD under random synergistic crowd is studied. Through the maximum， mean and standard deviation of the three comfort evaluation indexes of the 100 groups of acceleration， root mean square（RMS） value， and maximum 1-s RMS value， the control performance and robustness of different TMDs are analyzed. The results show that structural dynamic responses vary greatly due to the randomness of crowd and body parameters. In general， STMD with variable mass and damping has the best control performance， whose standard deviation is also the smallest， indicating the best robustness.