Research On The Dynamic Characteristic Of Floating Raft Vibration Isolation System For One Horizontal Pumping

The floating raft isolation system is a kind of effective noise reduction device. It can restrain the vibration transmission from machine to hull, the related theory and test research has also become the hot spot of isolation technology research. The domestic and foreign scholars had already done a lot of work for the dynamic characteristics and vibration response. These studies involving much of the military aspects, but in civil aspects are rare. At present, there are also many theoretical problems remain to be solved in engineering practical application.This paper based on engineering project, researching the dynamic characteristics of pump floating raft isolation system and applying the floating raft isolation technology in engineering practice, which has important theoretical significance and practical value to increase vibration isolation efficiency and improve the machine running environment, the concrete research contents as follows:The synthesis of mobility matrixes is an effective method of researching the power flow in floating raft system, particularly confines to simple structure, such as beam or plate, whose mobility matrixes can be obtained by analysis. This paper based on floating raft isolation system of circulating water pump, the system is simplified to five sub-structure which are units, upper vibration isolators, elastic raft frame, low vibration isolators, elastic foundation and so on. Using sub-structure mobility matrixes to establish the dynamic model of the whole body. This paper research the power flow transfer characteristics of raft isolation system combining with numerical calculations are simulation, which can provide theoretical basis for raft isolation system designing.In this paper, carrying on the finite element modeling and the modal analysis by using finite element analysis software ANSYS for a practical raft vibration isolation system. First, carrying on the finite element modeling to the raft frame, the vibration isolator and the system, then carrying on the modal analysis to the raft and the system. Obtained the raft and overall system's partial modes and analyzed the raft and system's dynamic characteristic. Besides, forced harmonic vibration analysis are finished by using ANSYS then came to the system's frequency dynamic response curve.Based on the purposed theory, the article sets up theoretical model and experimental model of raft isolation system, collects the impacted and responding data of each point by virtue of traveling hammering method, identifies the modal parameters of roots blower and compares with the FEM results, which testifies the validity of FEM.