Modal parameter identification for closely spaced modes using an Empirical Fourier decomposition-based method

Precise and effective identification of modal parameters is important for a civil structure throughout the structural lifetime. A time-frequency method parameter developed based on recently adaptive signal decomposition, i.e., empirical Fourier decomposition (EFD). The EFD used to separate multi-component free vibration response into summation several mono-component responses. frequencies damping ratios are calculated from responses by using envelope estimation method. Two numerical examples one experimental example provided validate EFD-based highlight improvements relative mode (EMD)-based It highlighted that has much higher frequency resolution lower computational cost than EMD-based Hence, proposed suitable online identifications structures with closely spaced modes. In addition, useful both linear nonlinear systems.