Abstract: Harmonic response analysis and time history analysis are both most commonly used to analyze the vibration responses of powerhouse structure. In order to analyze the differences between these two methods, we calculated the vibration responses of powerhouse structure of a pumped storage station under pressure fluctuations using the two methods. By comparing the vibration amplitude, vibration speed, vibration acceleration and dynamic stresses of powerhouse structure, we obtained the differences between these two methods. Results suggest that the root mean square values of vibration amplitude, vibration speed and acceleration calculated by harmonic response analysis are bigger and peak values are smaller than those calculated by time history analysis. The dynamic stress of powerhouse structure calculated by the two methods are both small and the difference between the results is also small. When the time-history data of pressure fluctuation is available, time history analysis method is preferable; if not, harmonic method can also be used to analyse the dynamic responses of powerhouse structure.

Key words: harmonic response analysis, time history analysis, pressure fluctuation, powerhouse structure, dynamic response