Modal and Harmonic Response Analyses of the Kenyir Dam Intake Section

Abstract

Modal and harmonic responses are the important analyses that need to be carried out to determine the behavior of a structure by executing data in a real-time. Through these analyses, several parameters of the structure can be identified. These parameters which are natural frequencies, mode shapes and frequency response function (FRF) are critical for monitoring and investigating of the dynamic behavior as well as to avoid unnecessary resonance to the structure. In this paper, the intake section of Kenyir Hydropower Dam in Terengganu, Malaysia is taken into consideration for the modal and harmonic response analyses. Numerical study using ANSYS software is performed for the real scale size of the intake section with a proper boundary condition. Six most significant result are selected from the modal analysis including the FRF for all three axes of the intake section. From the FRFs, the highest natural frequency value occurred at 11.024 Hz with the maximum deflection of 2.3203 m in the y-direction direction. This value must be taken into consideration for any external induced vibration to avoid the failure of the dam structure.