ODS Analysis is a testing procedure used to define the system structural deformation pattern resulting from a dynamic forcing function at a specific frequency. The same commercially-available experimental modal analysis software can be used to curve-fit and animate the operating deflection shape. An ODS Analysis, by itself, does not provide enough information to determine a structure’s modal parameters. The ODS Analysis produces a display of the relative structural deformation of a system resulting from an actual forcing function. If the frequency of the forcing function coincides with a natural frequency of the supporting structure or of a machine component, then the ODS provides a good estimate
of that mode shape. If the forcing function frequency does not coincide with any natural frequency, then the ODS is merely a display of the normal structural response of the system and not a mode shape. The test is performed while the machine is operating and much quicker than an experimental modal analysis test.