Seismic analysis of nuclear reactor core

A 3-D homogenization model is proposed to study the overall dynamic behavio ur of a nuclear reactor core under seismic excitation. Finite element metho d is employed for detailed analysis. As the fluid-structure interaction in the core gives rise to a non-conservative force, the mass and stiffness mat rices of the system are non-symmetrical. Both Wilson-theta direct integrati on method and QZ method were used to calculate the seismic response of the reactor core. Results of responses of the fluid pressure and the beam defle ction under excitation of EI-Centro and Tangshan seismic waves are presente d. In order to validate the model, analytic solution of the dynamic respons e of a single beam immersed in an infinite fluid is also given. (C) 2001 El sevier Science Ltd. All rights reserved.