Modal Parameter Identification Method of Jacket Platform Structure Based on AFDD and Optimized FBFFT

作     者：LENG Jian-cheng MA Jin-yong FAN Zong-heng QIAN Wan-dong FENG Hui-yu LENG Jian-cheng;MA Jin-yong;FAN Zong-heng;QIAN Wan-dong;FENG Hui-yu

作者机构：School of Mechanical Science and EngineeringNortheast Petroleum UniversityDaqing 163318China 

出 版 物：《China Ocean Engineering》 (中国海洋工程（英文版）)

年 卷 期：2023年第37卷第3期

页      面：393-407页

核心收录：

学科分类：08[工学] 0707[理学-海洋科学] 0824[工学-船舶与海洋工程] 0814[工学-土木工程] 0701[理学-数学] 

基　　金：financially supported by the Natural Science Foundation of Heilongjiang Province of China (Grant No. LH2020E016) the National Natural Science Foundation of China (Grant No.11472076)。 

主　　题：jacket platform uncertain modal parameter identification FBFFT method environmental excitation AFDD method Powell optimization 

摘      要：Offshore platforms are susceptible to structural damage due to prolonged exposure to random loads,such as wind,waves,and currents.This is particularly true for platforms that have been in service for an extended period.Identifying the modal parameters of offshore platforms is crucial for damage diagno sis,as it serves as a prerequisite and foundation for the process.Therefore,it holds great significance to prioritize the identification of these parameters.Aiming at the shortcomings of the traditional Fast Bayesian Fast Fourier Transform(FBFFT) method,this paper proposes a modal parameter identification method based on Automatic Frequency Domain Decomposition(AFDD) and optimized FBFFT.By introducing the AFDD method and Powell optimization algorithm,this method can automatically identify the initial value of natural frequency and solve the objective function efficiently and simply.In order to verify the feasibility and effectiveness of the proposed method,it is used to identify the modal parameters of the IASC-ASCE benchmark model and the j acket platform structure model,and the Most Probable Value(MPV) of the modal parameters and their respective posterior uncertainties are successfully identified.The identification results of the IASC-ASCE benc hmark model are compared with the identification re sults of the MODE-ID method,which verifies the effectivene ss and accuracy of the proposed method for identifying modal parameters.It provides a simple and feasible method for quantifying the influence of uncertain factors such as environmental parameters on the identification results,and also provide s a reference for modal parameter identification of other large structures.