# Evaluating & Using Data

March 29, 2018

Understanding and evaluating the data collected in a vibration test helps to explain the effects of the various forms of vibration testing. At what frequency did the DUT fail? How does the test compare to the required standards? How much acceleration was the DUT experiencing at a particular time or frequency? How much displacement is required from the shaker to run the test profile? The answers to these questions and more can be obtained through an understanding of the graphs and data generated by VibrationVIEW.

### Acceleration vs. Time Graph (Acceleration Waveform)

The acceleration waveform graph displays the acceleration experienced by the DUT for a snapshot of time. Specifically, it is the acceleration value being measured at the exact point where the accelerometer is mounted at a specific moment in time.

### Acceleration Spectrum

The acceleration spectrum is mostly used in System Check. It displays the changes in acceleration with respect to frequency. This graph is useful for observing harmonic frequencies and noise.

### Acceleration vs. Frequency Graph (Acceleration Profile)

The Acceleration vs. Frequency graph displays test progression as well as the tolerance and abort limits set in the test profile. This graph can also be used 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 one channel to another. It is used to view resonances.

### Probability Density Function

A PDF indicates how the acceleration of a test profile is distributed. As a test progresses, the graph will curve where the majority of the test acceleration is occurring. To observe how the curve is generated look at a random acceleration waveform in comparison.

### Time History – Acceleration, Velocity, Displacement, Frequency

The time history graph displays a time history of the test profile. Typically, it is used to observe changes due to dwelling at resonance. This is determined by observing the changes in acceleration over time.

### Using the Data

The data must be post-processed after a test profile has run. There are a variety of post-processing forms that are determined by the goal of the test.

If the goal of a test is to minimize resonances at various frequencies and the test results show high resonances at a particular frequency, then the product must be redesigned to reduce the resonance. VibrationVIEW can automatically generate reports to display measurements and graphs related to the test profile.

### Special Features

VibrationVIEW has many unique features and capabilities. Several have been covered in this manual, but much of the software’s capability is still to be discovered.

Many of the software’s features are best explained in a visual format. The Vibration Research sales and support team routinely creates new Webinars and Training Videos, all of which are available in the knowledgebase.

Key introductory webinars include:

1. Software Releases
2. Setting up your Controller (Version 10)
3. 10 Things you can do with your VR9500 (Version 2014)
4. Safety Limits (Version 9)
5. Data, Data, Data: Saving, Converting, Importing, and Exporting Data
6. Tips & Tricks (Version 2019)