Experimental Study on the Seismic Dynamic Response of a Valve Tower on an Offshore Converter Platform

Abstract

With the development of offshore wind power towards deep-sea areas, the offshore valve tower, as a key facility of offshore wind farms, plays a vital role in ensuring the stable operation of the system. To investigate its dynamic response characteristics under seismic loading, a 1:25 physical test model of the valve tower was constructed based on the gravity–elasticity similarity principle. Acceleration responses at the first deck of a 1:65 scale offshore converter platform model were obtained through shaking-table tests and applied as base excitation to the valve tower model. The experimental results reveal that the frequency domain response of the valve tower transitions from high-frequency dominance at the base to low-frequency dominance at the top, with the structural weak link located at the mid-connection between the front and rear sub-towers. The fundamental frequency of the valve tower is 3.92 Hz, and the average damping ratio is 3.21%. The shake table test of the converter valve tower was verified using the gravity–elasticity similarity law, effectively reproducing the seismic response characteristics of the prototype. This provides crucial data for seismic response spectrum analysis, identifies structural weaknesses, and offers guidance for the design of more earthquake-resistant offshore valve towers, thus enhancing the safety of deep-sea wind farms.

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