Modal damping effects on the spatial distribution of anelastic damped vibration energy for a baseline cantilever structure

摘要

Modal damping was conceived as a vibration control concept for potential application to a select set of long, flexible structures. This alternative approach was designed to exploit damping mechanisms inherent in the structures of interest by capitalizing on distinctive dynamic properties existing among vibration modes. The premise of modal damping is to transfer vibration energy from the fundamental mode where most vibration energy of civil structures of interest resides, to higher order modes where vibration impedance was shown to be more effective. A question was posed during its development concerning the subsequent risks to the structure. Spatial displacements, velocities and accelerations along the longitudinal axis will clearly be impacted and can readily be evaluated by simulation as required. The specific inquiry was directed at risks associated with redistribution of the damped vibration energy. In response, the distribution dynamics associated with the simple but ever-present anelastic damping mechanism was investigated and quantified. Furthermore, the analysis additionally offers support of the modal damping assertion by providing insight behind the increased dissipation effectiveness of the 2nd vibration mode over that of the fundamental mode.