ANALYTICAL STUDY ON DYNAMIC BUCKLING OF REACTOR CONTAINMENT VESSEL

The dynamic buckling of a reactor containment vessel under earthquake conditions is evaluated using a nonlinear finite element method. It is based on the four-node MITC (mixed interpolated tensorial components) shell element originally proposed by K.J. Bathe, which has been modif ied by the authors to include the effect of large rotational increment s. At first, the buckling modes for a thin cylindrical shell under a s implified base excitation were classified, then the dynamic buckling a nalysis of a typical PWR steel containment vessel was carried out, con sidering both geometrical and material nonlinearities, to compare the results with those of a conventional static analysis. It was found tha t the global shear buckling of a steel containment vessel occurred und er a load level several times greater than the design earthquake, and the buckling load estimated by the conventional analysis was smaller t han the buckling load estimated by the dynamic analysis. (C) 1997 Else vier Science S.A.