Active Control of Structures with Closely Space Natural Frequencies and Unsymmetrical Modes

Abstract:

The structure with closely spaced natural frequencies and unsymmetrical modes is analyzed under pseudo impulses installed with one or two active mass damper (AMDs). The distribution of the implemental damping ratios of different modes is evaluated under state and velocity feedbacks. An experimental model of cable stayed bridge with closely spaced natural frequencies is build up to verify the theoretical results under control. Modal analysis show that the experimental results agree well with the theoretical results of modal parameters including frequencies and modal damping ratios.

Key words:structures with closely spaced natural frequencies; active control; modes with closely spaced natural frequencies; modal analysis; model experiment