Research on Frequency Domain Analysis Method Based on Equivalent Linearization for a Base-isolated Nuclear Power Plant
Sub-structuring method is generally used in the soil-structure interaction(SSI)analysis for nuclear structures due to that such method is of the semi-analytic foundation simulation technique,the high calculation efficiency and constant damping of the whole analysis system.Therefore,the sub-structuring method can be adopted in SSI analysis for base-isolated buildings.However,the sub-structuring method has limitations to solve base-isolation problem because it bases on the superposition theory while the isolation bear-ing has significant non-linear characteristic.To solve this problem,we simulate the nonlinear behavior of the isolation bearing based on the concept of equivalent linearization in sub-structuring method and verify its feasibility by using SAP2000.In this paper,the method was applied to the in-structure response spectrum(ISRS)calculation of a base-isolated nuclear building under different site conditions,and the results were compared with those from the calculation using the equivalent stiffness of bi-linear constitutive model of the bear-ing.Our results show that the hysteresis curve of the isolation bearing obtained by the sub-structuring method is basically consistent with that from the nonlinear calculation in SAP2000,which proves that the method is reasonable and feasible.Compared with the ISRS obtained by using the equivalent stiffness,the zero-period acceleration of the ISRS obtained by using the convergent stiffness do not change too much,and the dominant frequencies decreased with slight increase of the peak acceleration.The ISRS of the base-isolated structure is not sensitive to the change of the site conditions since the predominant frequency of the isolation system is not close to the predominant frequencies of the sites.
Nuclear power plantSub-structuring methodIsolation bearingEquivalent linearization
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维普
