Modal analysis of multi-degree-of-freedom dynamic system based on non-stationary response data

作者：Tang Da; Wang Zhihao^*; Yue Qianjin; Shi Zhongmin; Feng Jiaguo

来源：Journal of Sound and Vibration, 2015, 347: 139-149.

DOI：10.1016/j.jsv.2015.02.008

In connection with the nonstationarity of the huge offshore structure monitoring data, a method of constructing structure free response based on the non stationary response data is proposed. This method uses a unilateral moving average to stabilize loads and the response data in the dynamic model of the multi-degree-of-freedom (mdof) structure, analyzes spectral characteristics of moving averages in some orders, researches filtering effects when the order q = 1 (difference) and q > 1 and constructs the free vibration equation of the structure by the random decrement technique (PDT). Through the identification of the second order linear system simulation model, a comparison of modal parameters with the theoretical values is given, which are identified by different methods, and it shows good effects on the analysis of non stationary response data using this method. Finally, the method is applied to the mode identification of the Floating Production Storage and Offloading (FPSO) single point mooring structure, the distribution of the modal parameters of single point mooring structure is analyzed and modal parameters identified by different values of q are compared.

• 出版日期2015-7-7
• 单位大连理工大学