Dynamic Characteristics Research Of Floating Raft Isolation Instruments In Ships

To control the vibration and noise in ship is always playing the important role in the theoretic and practical research of vibration isolation. The ship structural oscillatory issue arose from the dynamical mechanics is the emphases of the engineering research all the while. With the development of technology, the higher and stricter requests on the capability of the vibration isolation system are brought forward. To some extent, the traditional double-stage vibration isolation instrument can hardly meet the expectations. The floating raft oscillation isolation system developed in recent years is an effective instrument to ship dynamical mechanics to implement the isolation of noise and vibration.First of all, based on the review of investigative progress, the significance of the thesis is presented. And then, starting with the fundamental theory, several basic problems of vibration isolation are analyzed and calculated. Meanwhile, a vibration teaching experiment system named with ZJY-601 produced by China Orient Institute of Noise & Vibration is introduced briefly. In succession, the theory and steps of vibration isolation design are recommended, the devise and select principle, the classification and properties, as well as the installation and loads counting are introduced. And an active vibration isolation experiment is given to validate the theoretic result. Afterwards, the vibration isolation issue of floating raft system is studied, the mechanical model of floating raft is founded, the differential equation is deduced. Moreover, aiming at reducing the isolation transmission of the systemic structure oscillation, in terms of the functional parameters of isolators, the dynamical properties of floating raft system acted by oscillator is analyzed. By the optimization of dominating structural parameters, the approach achieving good vibration isolation features is discussed. So that a series of conclusions valuable in engineering are derived by the studies and contrasts of both theory and experiment, this part is the emphases of the thesis. Finally, a ship model equipped with a floating raft is designed. The finite element analysis is carried out with ANSYS software plus the experiment, the performance of vibration isolation system equipped with the floating raft installation is investigated.