Adams Basic Package > Adams Post Processor > Dialog Box - F1 help > Order Analysis Order Spectrum 3D

Order Analysis Order Spectrum 3D

This is an extension to the Adams Post Processor’s 3D FFT capability to allow generation of a 3D plot of an Adams result set component signal’s amplitude over RPM slices versus order. The RPM is from a user-chosen reference rotational velocity Adams result set component.
Edit → Plot → FFT 3D
Constructs a three-dimensional (3D) order spectrum plot by performing signal processing on individual slices of a curve with respect to reference rotational velocity. You define a slice size, and Adams PostProcessor slides this over a range of a curve, overlapping the slices as specified. Each slice of the curve becomes a row in the 3D plot surface.
 
Note:  
The order analysis algorithm assumes that the reference angular velocity has monotonically increasing values. User should make sure this condition is satisfied while selecting the reference angular velocity.
Also, the order analysis algorithm assumes the output step size (DTOUT) is constant. It’s recommended to remove the contact incidents from the output data so that DTOUT remains constant.
 
For the option:
Do the following:
Curve Name
Displays the name of the curve you are plotting.
Plot Type
Select one of the following:
■General 3D FFT - this option represents the existing 3D FFT capability
■Order Analysis Order Spectrum - this option sets the dialog for 3D order spectrum plots
Rotational Velocity
Select a result set component that represents to them the reference rotational velocity signal defining what constitutes order 1.
Specify Units
This option is only available if result set component’s unit type is not detectable.
Specify the units, and then it used to performs the conversion to RPM.
X-Axis
Order
Y-Axis
Select one of the following:
■Mag
■PSD
Z-Axis
RPM (Reference rotational velocity) is used by default.
Start Velocity (rpm)/End Velocity (rpm)
Enter the start and end velocity to define the entire range of the curve on which you want signal processing performed.
Note: If left blank at the time of dialog execution then both options will use the min/max value of rpm from the “Rotational Velocity” result set component.
Velocity Slice Size
Enter the width of a segment of the curve on which signal processing is to be carried out.
Default value is 10% of difference between minimum and maximum value of rpm in the “Rotational Velocity”.
Percentage Overlap
Enter the percentage amount the slices can overlap.
Window Type
Select the type of window you want to use.
Points/Points (Power of 2)
Select the number of points to be used for the Order Spectrum 3D.
The following options are only available if you selected PSD.
Number of Segments/
Segment Length
Enter the number of equal segments into which the signal will be split.
Or, you can enter the segment length directly. This is often referred to as the window length. A recommended number of segments is 8, with 50% overlap (see Overlap Points) between segments.
Overlap Points
Enter the number of overlaps, which indicates how many signal samples are used. With a 50% segment overlap and 8 segments as a recommendation, this number would be Points (Power of 2) / (8*2).