双层球面网壳振动主动控制作动器位置优化

为了确定双层球面网壳结构振动控制的作动器最佳布设位置/数目,以主动控制的二次型性能泛函最优控制理论为基础,定义作动器布设的敏感度,提出逐步删除结构中敏感度小的作动器优化过程,并编制相应的作动器优化实现程序.算例表明,对于双层球面网壳结构,作动器布设在上、下弦杆优于腹杆,且布设在上弦优于下弦;在结构位移和作动器的控制力均满足设定的要求下,结构上弦作动器布置距离中心越远其灵敏度越大,环向布置优于径向布置,作动器最佳布设位置在结构上弦的最外圈环向杆件上.算例进一步表明,对于不同的地震动输入,作动器在最佳位置上,相应的主动控制的效果均比较明显.

Optimal placements of actuators in vibration active control for double layer spherical grid shell structures

The sensitivity of actuator disposed in the members was defined based on the optimization theory of active control with quadratic performance function in order to ascertain the optimal placements and numbers of actuators in the active control for double layer spherical grid shell structures. An optimization process to successively delete the insensitive actuators was presented. Meanwhile, a Matlab program was developed. The numerical results for double layer spherical grid shell structure show that it is better to lay out the actuators in chords than in diagonal members, as well as in upper chords better than in lower chords. Under satisfying the requirements of restricted structural displacements and control forces of actuators, the farther from structural center the actuators are laid out in upper chords, the more sensitive they’ll be, and it is better to lay out the actuators circularly than radially. The optimal placements of actuators are in the outermost ring of upper chords for double layer spherical grid shell structures. Results also show that the effectiveness of active control is apparent under different seismic inputs while the actuators are laid out in the optimal placements.