An Overview of Major Developments and Issues in Modal Identification

During a revisit to modal identification in the past three decades, an overview of the major developments and issues in modal identification is motivated. A brief review on the progress from Single-Input/Single-Output (SISO), Single-Input/Multi-Output (SIMO) to Multi-Input/Multi-Output (MIMO) identification in frequency, time and spatial domain, is presented. The latest developments and issues are then discussed, which cover (1) Traditional Experimental Modal Analysis (EMA) using both Input/Output measurements and Operational Modal Analysis using Output data only; (2) Two-stage modal identification and one-stage modal identification, and (3) Deterministic modal identification and statistical modal identification, which takes measurement noise and system uncertainty into account.