摘要
This paper investigates the possibility of utilizing response from natural ice loading for modal parameter identification of real offshore platforms.The test platform is the JZ20-2 MUQ jacket platform located in the Liaodong Bay,China.A field experiment is carried out in winter season,as the platform is excited by floating ices.The feasibility is demonstrated by the acceleration response of two different segments.By the SSI-data method,the modal frequencies and damping ratios of four structural modes can be successfully identified from both segments.The estimated information from both segments is almost identical,which demonstrates that the modal identification is trustworthy.Furthermore,by taking the Jacket platform as a benchmark,the numerical performance of five popular time-domain EMA methods is systematically compared from different viewpoints.The comparisons are categorized as:(1)stochastic methods versus deterministic methods;(2)high-order methods versus low-order methods;(3)data-driven versus covariance-driven stochastic subspace identification methods.
基金
financially supported by the National Science Fund for Distinguished Young Scholars(Grant No.51625902)
the Major Scientific and Technological Innovation Project of Shandong Province(Grant No.2019JZZY010820)
the National Key Research and Development Program of China(Grant No.2019YFC0312404)
the National Natural Science Foundation of China(Grant No.51879249)
the Taishan Scholars Program of Shandong Province(Grant No.TS201511016)。
