Select Function Task

In the Select Function task, the FRF from which the poles will estimated is chosen and the frequency band around the mode of interest is selected. Information about the FRF dataset is displayed in the Info panel. Hovering the mouse pointer over AFU Name will show some additional information about the FRF dataset. The FRF that is plotted is the function selected for parameter estimation. Although any number of FRF can be plotted, the user cannot proceed to the next task unless only one FRF is selected.

Freq Range : Lower & Upper Freq – Enter the lower and upper limits of the frequency range to be processed. These values can also be set using the two cursors in the plot axes. There is a context menu on the edit boxes from which to set the full frequency range.

Plot Function – The only Plot Function is FRF.

References – Select the reference of the plotted FRF. Only one reference can be selected. Use the context menu to select the attributes listed or displayed in the legend or to plot the drive point FRF.

Responses – Select the responses of the plotted FRF. Use the context menu to select the attributes listed or displayed in the legend, delist selected responses, list all responses, list by coordinate trace, find a response, or open the Responses dialog.

Selecting Find Response from the context menu presents an input dialog into which a response coordinate (e.g., 1234X+ or 1234X) or node (e.g., 1234) is entered. Any response with the specified coordinate or node will be found and plotted. The direction sense (i.e., +/−) is not required and if omitted, any response coordinate with the positive or negative sense of the specified direction will be found.

Slide Show – The slide show is an automated means to sequentially plot FRFs by incrementing one response. The slide show controls on the toolbar are meant to have similar functionality to the buttons on a DVD player remote control. The slide show can step one response forward or reverse, or play the responses forward or reverse sequentially. In the slide show play mode, the response is automatically incremented on a timed interval. The Slide Show Pause Interval is set in the Preferences dialog.