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Module 2.2 – Advanced Random Test

March 29, 2018

Background

Why Test?
Testing Standards
Tools for Testing
Download Demo Software

Using VibrationVIEW

Getting Started
Before Starting a Test
Test Types: Sine
Test Types: Random
Test Types: Shock, Mixed Mode & FDR
Test Sequencing
Reports & Analysis
Graphing Test Data

Laboratory Exercises

Exercises
Module 1.1 – Simple Sine Test
Module 1.2 – Simple Sine Resonance Tracked Dwell (SRTD)
Module 1.3 – Advanced SRTD
Module 2.1 – Simple Random Test
Module 2.2 – Advanced Random Test
Module 2.3 – Kurtosion® vs. Traditional Random Test
Module 2.4 – Kurtosion® with Varying Transition Band Frequency
Module 3.1 – Shock Testing
Module 4.1 – Multi-Mode Testing Sine-on-Random
Module 4.2 – Multi-Mode Testing Random-on-Random
Module 5.1 – Shock Response Spectrum (SRS) Test
Module 6.1 – Field Data Replication (FDR) Test

Reference

Works Cited
Download Entire Syllabus

Back to: VibrationVIEW Syllabus

For Demo Mode only.

Module 2.2 runs an advanced random test. You will create the breakpoint table and explore the advanced random test configuration. Note the Gaussian curve on the probability density function graph.

Use the Hardware, Inputs, and System Limits configuration from Module 1.1.

1. Create an Advanced Random Test

a.  Select New Test > Random.
b. Select Advanced.
c. Select Table and enter the following breakpoint table:

Frequency (Hz) Amplitude (G2/Hz)
2 0.00036
4 0.036
5 0.036
7 0.0016
11 0.013224
21 0.013224
50 0.00032
100 0.00032

d. Select Schedule and set the Run for time to 7 minutes and 30 seconds.
e. Select Limits and enter the following limits:

Spectrum Limits

(+) (-)
Tol 3 dB 3 dB
Channel Tol 3 dB 3 dB
Abort 6 dB 6 dB

RMS Limits

(+) (-)
Tol RMS 6 dB 6 dB
Channel Tol RMS 6 dB 6 dB
Abort RMS 9 dB 9 dB

Startup Drive Limits

Max System Gain 5 Volts/G
Output Threshold 0.05 Volts rms
First drive check 20%
Second drive check 50%

Running Drive Limits

Max System Gain 6 Volts/G
Max Output 6 Volts rms

f. Select OK and save the test as StudentName_AdvancedRandom.

2. Create the Graphs

Graph 1 Configuration

      • Graph Type: Acceleration vs. Freq.
      • Input Channels: Ch1, Ch2
      • Select “Show active lines”

Graph 2 Configuration

      • Graph Type: Acceleration Waveform
      • Input Channels: Ch1

Graph 3 Configuration

      • Graph Type: Probability Density
      • Input Channels: Ch1
      • Point to Axis Limits and change the y-axis to Log

3. Run the Test

a. Autoscale the graphs as needed.
b. Listen to the test.
c. Save the data.

Questions

  1. What are the maximum force values (G) on the acceleration waveform graph?
  2. Compare the probability density graph to the acceleration waveform. How do these graphs complement each other?
  3. Why don’t you hear anything when the test is running?

Answers in syllabus PDF.