Vibration Reduction Research On Ocean Engineering Cabin

Ocean engineering structure works in complex marine environment. It is equipedwith many supporting and accessory systems, which need to meet the production andpersonnel expenses. These systems’ working will inevitably bring complicatedstructural vibration and noise problems. Additionally, ocean engineering structure ismainly composed of steel frame and plates, the vibration and noise generated byvirious kinds of mechanical equipments are transmitted easily for its low damping.With the development of industial technology and people’s increasing attention totheir health, the international vibration and noise requirments for ocean engineeringcabin, especially in which people work or live for much long time, are becoming morehigher.In order to make research on vibration and noise control of ocean engineeringcabin, the author has made a field measurement on cabin decks vibrationcharacteristics of a jackup platform when it is in typical working conditions. A designthinking of frequency stagger is adopted for these vibration characteristics, and afloating floor structure composed of aluminum honeycomb sandwich plates andrubber dampers is tried for vibration and noise reduction.The exsiting honeycomb sandwich plate equivalent theories are summerized. Forthe aluminum honeycomb sandwich plate used in this paper, Sandwich equivalenttheory combining with Shell91element in ANSYS FEM software are adopted for thestructure’s simplification. Through physical expriment and simulation caculation, thecore material parameters of aluminum sandwich plate are determined. Meanwhile,through simulaiton caculation, we also found the influence the correction factormatters made to the equivalent result, and for different plate structures, the influenceis also different obviously. So it is necessary to determine the correction factor valuethrough experimental and computational methods in using this theory.Based on field measured cabin deck vibration spectrum characteristcs, this research uses a floating vibration isolation structure that constituted by aluminumhoneycomb sandwich plates and rubber dampers. Equivalent material parameters ofthe aluminum honeycomb sandwich plates are determined and the floating floorstructure is desighed firstly, then the simulation caculation model of floating floorstructure is built. By caculation and analysis, the absorber’s parameters whichdesigned for staggering the predominant frequency of upper accommodation deck isdetermined. This paper also analyes the infuence different structure parameters madeto its performance of vibration control.With one of the structure parameters made in simulation caculation, a physicalexperiment structure is made. By intensity comparasion between the response of themeasure point on the plate and accommodation deck vibration, a good vibrationisolation effect under designing load is performed., which also proves that thesimulation model is reasonable and effective to some extend and could play an activeguiding role in the structure’s optimization.