Concept demonstration of modal damping,a nonlinear structural vibration control scheme applied to a small scale vibrating aluminum cantilever model

Abstract

Modal damping was conceived as a vibration control concept that could possibly be applied to a select set of long, flexible structures. The approach was designed to exploit damping mechanisms inherent in structures by capitalizing on distinctive dynamic properties existing among the structure’s vibration modes. Modal damping transfers vibration energy from the fundamental mode where most vibration energy of civil structures of interest resides, to higher order modes where vibration impedance was found to be more effective. The closed-loop, semi-active control concept was first investigated by way of dynamic simulation. The results reflected improved settling times and prompted a concept demonstration test using a small-scale structure that was modeled after a real-world and highly dynamic structure. The experimental results were found to corroborate those of the simulation. Of particular interest was the engineered control system designed to effect inter-modal energy transfer using motion control forces virtually self-generated by the motion of the structure itself.