Output-only underdetermined modal parameters identification based on block term decomposition

Research on the use of limited sensor measurement information to identify modal parameters in underdetermined situation has important engineering application values. This paper proposes an under determined modal parameters identification method based on block term decomposition (BTD). By transforming the underdetermined modal parameters identification problem into tensor uniqueness decomposition problem, the connection between modal parameters identification and tensor decomposition is established, and the algorithm is optimized to solve the problem of uncertain sequence of source signals after decomposition. Finally, through a numerical simulation example and an experiment of a certain type of solid rocket motor structure, the ability of the proposed method in dealing with the identification of underdetermined modal parameters is verified, demonstrating good engineering application prospects.