Structural modal parameter identification method and system considering excitation non-stability

The invention discloses a structural modal parameter identification method and system considering excitation non-stationary degree. The method comprises the following steps: obtaining a structural response time domain signal under non-stationary excitation and intercepting the time domain signal; decoupling the intercepted time domain signal to obtain a structural modal response signal and a positive definite vibration mode or an underdefinite vibration mode of the structure; evaluating the structural load non-stationary degree based on the structural modal response signal, and extracting a non-stationary modal response signal to be subjected to stationary processing based on a set non-stationary threshold value; performing stabilization processing on the non-stationary modal response signal based on Hilbert transform in combination with time-averaging processing to obtain an equivalent stationary modal response signal; and performing modal parameter identification on the equivalent stationary modal response