Operational Modal Analysis - Another Way of Doing Modal Testing

Operational modal analysis (often called output-only or ambient modal analysis) is described in this article. Modal testing is performed on a plate structure with well-defined modes, resonance frequencies and damping values. Frequency Domain Decomposition (FDD) and Enhanced Frequency Domain Decomposition (EFDD) concepts are presented and applied to a plate structure. This article details the signal processing mathematical background and presents alternative curve-fitting processes.