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Calculating Velocity in the Toolbox

Stephen HanlyStephen Hanly Member, Administrator, Moderator Posts: 63 admin
edited July 2020 in Measurement & Analysis

This example uses the train data (https://community.endaq.com/discussion/75/vibration-from-bridge-as-train-passes-overhead#latest) to calculate velocity in three ways:

  • Straight integration and double integration
  • Calculating a PSD, then integrating that
  • Calculating a shock response spectrum pseudo velocity which tries to define severity (admittedly this is better for shock, not vibration data)

Here is the video of the analysis:

Double Integration

First is the x axis

Then the y axis

Now the z axis


The RMS of each is calculated:

  • X Axis: 0.4g
  • Y Axis: 1.0g
  • Z Axis: 0.7g

Now calculating the PSD in velocity, here is the RMS:

  • X Axis: 0.15 in/s
  • Y Axis: 0.70 in/s
  • Z Axis: 0.38 in/s

Pseudo Velocity Shock Response Spectrum

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