Graphing Test Data
March 29, 2018
Background
Using VibrationVIEW
Laboratory Exercises
Reference
Back to: VibrationVIEW Syllabus
Evaluating vibration test data offers insight into the response of the device under test (DUT). It can answer questions like:
- At which frequency did the DUT fail?
- How does the test compare to the standard?
- What acceleration level did the DUT experience at a particular time or frequency?
- How much displacement is needed from the shaker to run the test profile?
Basic Graph Types in VibrationVIEW
Acceleration Waveform
The acceleration waveform graph displays the acceleration value measured at the accelerometer’s location at a specific moment in time.
Acceleration Spectrum
The acceleration spectrum displays changes in acceleration with respect to frequency. This graph is useful for observing harmonic frequencies and noise when running System Check.
Acceleration vs. Frequency Graph (Acceleration Profile)
The acceleration vs. frequency graph displays a test’s progression and the user-defined tolerance and abort limits. Engineers can use it to view resonances or noise in relation to the control channel via a response accelerometer.
Drive Signal
The drive signal displays the voltage density as it changes with respect to frequency.
Transmissibility
Transmissibility is a ratio of the acceleration of two channels. Engineers often use it to evaluate resonances.
Probability Density Function (PDF)
A PDF indicates the distribution of test acceleration. As the test progresses, the graph will curve at the acceleration value the test experiences most often. Use a random acceleration waveform for comparison to observe how the curve is generated.
Time History: Acceleration, Velocity, Displacement, Frequency
The time-history graph displays a time history of the test profile. Typically, engineers use an acceleration time history to observe changes following a resonance dwell.
