Tendency of Damping Ratio of Floating Artificial Base by Experiment and Measurement Available to Purchase

It is important to estimate both added mass and radiation damping of floating artificial base, which is floating structure, in fluid-structure interaction problem. When a floating artificial base shows elastic behavior, its damping contains both structural damping and radiation damping. Therefore it is difficult to estimate the damping. We aimed to grasp tendencies of damping, when a floating artificial base shows elastic behavior, by both experiment and field measurement. The experimental modal analysis using elastic plate models was carried out and tendencies of damping ratio of experimental models were grasped. Besides, damping ratio of an existent floating artificial base was calculated from measured vibration data by the Random Decrement Technique (RDT). In our experimental results, the damping ratio became larger value in lower vibration mode, and then it decreased in higher vibration mode. In higher vibration mode, we could not confirm radiation damping. It is thought that structural damping accounts for nearly all of obtained damping ratio. Consequently, it is appropriate that damping ratio of the floating artificial base is evaluated as Rayleigh type damping.