Shock Absorption Study On Offshore Platform With Storage Tank Used As TLD

Offshore platform with storage tank is widely used in offshore oil exploitation. Variously complex accidental loads such as earthquake, wave, wind, ice and so on acted on the platform. Because the storage tank effects on the structure excited by earthquake, wave, ice, the dynamical peculiarity of the offshore platform with storage tank is different from the common platform. If the earthquake destroys the platform with oil storage tank, it will damage the tank and leak the oil then cause the awful hypo-disaster. Therefore, it is very important for the platforms to decrease the vibration due to the environmental loads.Firstly, the dynamical peculiarity of the platform under various dynamical loads is studied through theoretical calculation. Five-structure systems are based on the different liquid depths of the storage tank by ANSYS and calculated the frequencies and mode shapes. Then the dynamic response (the structural displacement and stress) of the different structure systems due to some kinds of dynamical loads are calculated. The conclusion is that the biggest response depth in the five-structure systems is the full tank of the storage tank. At the same time, the influence of the structure under seismic wave is much bigger than the one under the random wave and dynamical ice force.Secondly, the shock-absorption influence on the offshore platform with storage tank used as TLD is investigated through model test. The change characteristic of the oscillation force, wave-high and hydraulic pressure of the liquid in the columned container is studied. Then the design of the model test is introduced. At length the dynamical response data of the model excited by the artificial seismic wave, TJ seismic wave, the dynamical ice and random wave force is supplied, and it proves the feasibility to the platform with TLD. The experiment confirms that storage tanks used as tuned liquid damper are effective and feasible on shock absorption.Lastly, the shock-absorption effect of the structure system with TLD designed on the full tank is proved through the theoretical analysis. The structure with TLD under the artificial seismic wave, TJ seismic wave, the dynamical ice force and the random wave is analyzed. The conclusion is that TLD is effective on the shock absorption by the seismic wave, and not reverse to the structure shock by the dynamical ice and random wave force.