The Waveform Editor is tool to modify time waveforms so they fit the requirement of replication on a shaker. It can splice, crop, filter, and apply compensation to acceleration, velocity, and displacement waveforms. It is different from the Post Analysis application in that it does not do FFTs or any other form of higher analysis.
- Line number for spectral analysis sets the number of spectral lines. More lines increase the resolution of frequency data.
- Bin Number sets the resolution of histogram data.
- Profile Quantity sets the quantity as acceleration, velocity, displacement, or voltage.
- Undo Max. Step sets the number of cached operations for the Undo command
- Start Average Frame sets the starting frame of the average.
Compensation involves modifying the time stream so it meets certain constraints in velocity, displacement, or acceleration. Compensation operations include Acceleration DC Removal, Velocity DC Removal, and High/Low/Band Pass Filter. After the proper compensation template setup, one button can execute multiple operations.
- Acc. DC (Vel. Slope) Remove subtracts the DC component in the acceleration waveform. This removes a slope trend from the velocity waveform. It is needed when the raw data has an offset measurement error.
- Vel. DC (Disp. Slope) Remove subtracts the DC component in the velocity waveform. This removes a slope trend from the displacement waveform. It is useful when acceleration discontinuities are present. An acceleration discontinuity (a sharp spike in acceleration) will generate an offset in the velocity profile which then results in a slope in the displacement.
- High Pass Filter suppresses low-frequency signals below the specified cutoff frequency. This method is effective in reducing displacement but may also remove desirable low frequency energy. The cutoff frequency should be set as low as possible while still maintaining the displacement requirement.
- Low Pass Filter suppresses high-frequency signals above the specified cutoff frequency. This does not have a major impact on the displacement or velocity profile. It is useful in that it will help remove high-frequency components that are undesirable in the acceleration waveform.
- Band Pass Filter combines a Low-Pass and High-Pass filter.
The Shaker Settings define the limits of the shaker that will be used to output the waveform.
The Splice operation is used to minimize boundary discontinuities when two pieces of data are put together. Once enabled, the chosen Data Window will be applied to the data array at both ends for the following cases:
A piece of data is appended to the previous segment during the file import process.
A piece of data is inserted or pasted into an existing segment.
In the Splice Settings dialog you will be able to define the following: Data Window, Overlapping, and Number of Windowing Points.
The user can choose different Data Window types to be used in the Splice operation.
- None Disables the Splice function
- Hanning Uses a Hanning window during the Splice operation.
- Triangle Uses a Triangular window during the Splice operation
- Half Sine Uses Half Sine window during the Splice operatio
1. With Overlapping Two pieces of data will be put together with Data Window overlapping. Note that the total length of the profile will be reduced after splicing.
2. No Overlapping Data Windows are not overlapped. The length of the profile will not be altered.