人行荷载作用下大跨悬挂楼盖调频阻尼控制研究

Study on tuned damping control of large-span suspension floor in pedestrian load

针对一竖向振动频率处于人行荷载范围的场馆大跨悬挂楼盖进行调频阻尼减振控制研究,对比分析场馆整体结构模型和大跨悬挂楼盖局部简化模型的动力特性,基于最优控制原则设计调频质量阻尼器的参数和布置位置,在一般人群随机荷载、极端人群随机荷载、节拍及跳跃人群荷载等12种人行工况下,研究无控和有控大跨悬挂楼盖结构的人激动力响应.结果表明,楼盖结构在无控条件下的振动加速度响应大大超过限值要求,但通过合理的调频阻尼减振设计,有效抑制该大跨楼盖人激振动响应,最大峰值加速度减振效果达61%;楼盖结构位移响应很小,虽在人激荷载作用下可不予考虑,但调频阻尼器仍对其具有良好的控制效果.研究成果可为类似工程结构在人行荷载作用下的控制设计提供借鉴参考.

Vibration induced by pedestrian loading of a suspension floor in a venue building is studied and controlled by tuned mass damper in this paper as its vertical frequency lies in the range of the pedestrian load. A simplified floor model was proposed and verified by comparison of dynamic characteristics with the original overall structure to save computational time. The design parameters and installation locations of the tuned mass dampers were determined based on optimal control design principles. Dynamic responses of the simplified suspension floor with and without tuned mass damper under 12 kinds of pedestrian cases, such as general random pedestrian cases, extremely random pedestrian cases, beat and jump pedestrian cases, were investigated in detail. Results show that the peak acceleration responses of the floor without damper are much bigger than the limit requirement. However, the vibration responses are effectively controlled by the optimal designed tuned mass damper and up to 61% of the damping effect is achieved. In addition, although the displacement responses of the floor are very small and can be ignored in pedestrian loadings, good control effect can also be found by using the tuned mass damper. This paper sheds some lights on vibration control of similar engineering problems.