| Abstract: | A simple mapping finite element method is used to calculate the coupled natural frequencies and mode shapes of realistic arch dam reservoir systems in which the dam is circular cylindrical with non-uniform cross-section. This method, in which both the dam and the reservoir domains are mapped into geometrically simpler shapes using cylindrical-polar transformations, is found to give accurate results, achieved simply and economically. Results of analysis show that hydrodynamic interaction has a substantial effect on the coupled natural frequencies and mode shapes; also that the effect of water compressibility in the type of dams considered can be ignored without significant loss of accuracy. A simple method is also presented for predicting the water compressibility effect before undertaking detailed response analysis. |
