Host: The Japan Society of Mechanical Engineers
Name : Dynamics and Design Conference 2021
Date : September 13, 2021 - September 17, 2021
W In this study, we dealt with the problem of optimizing the installation and parameters of each dynamic damper when two dynamic dampers are distributed and installed in a three-layer structure against the base excitation. First, the optimum design of the single dynamic damper with a mass ratio of 0.1 was performed by the method using the fixed-point theory and the exhaustive search method of the parameters, and it was found that the accuracy of the latter method was sufficient. Next, when the masses of the two dynamic dampers are equal (both have a mass ratio of 0.05), the installation positions of the two dynamic dampers and the parameters of each dynamic damper were optimized. It was found that the optimum installation position is 2F + 3F. The vibration suppression performance was equivalent to that when the mass of the single dynamic damper was multiplied by 1.05. Furthermore, when two dynamic dampers were installed on 2F + 3F and the mass distribution of each dynamic damper was optimized, the optimum mass ratio was 0.02 for the dynamic damper on the 2nd floor and 0.08 for the dynamic damper on the 3rd floor. The vibration suppression performance was equivalent to that when the mass of the single dynamic damper was multiplied by 1.15. Finally, as a result of sensitivity analysis of the parameters of the two optimally designed dynamic dampers, it was found that the damping ratio is more robust than the frequency ratio. In other words, it was found that it is necessary to pay attention to the accuracy of the spring constant when actually making a dynamic damper.
