Estimation of modal parameters using the sparse component analysis based underdetermined blind source separation

• A novel method based on SCA-based UBSS is proposed to estimate modal parameters.
• Relationship with the TFR-based modal parameter identification method is revealed.
• The proposed method is confirmed by an experiment conducted on a column beam.
• The proposed method is applied to estimate time-varying modal parameters of a beam.

The underdetermined blind source separation method based on sparse component analysis in the time–frequency domain is introduced to estimate the modal parameters in this study. This study attempts to reveal the relationship with the modal parameter identification methods based on the time–frequency representation. A five-degree-of-freedom mass-spring-damper system and a real experiment conducted on a TC4 titanium-alloy column are used to confirm the proposed method. Furthermore the proposed method is applied to extract the time-varying modal parameters of the column in the temperature-varying environment. The extracted results evidently show the thermal effect on the modal parameters.