Structural Dynamics

Structural Dynamics

For a Random Vibration analysis,if I want to know the relative displacements between 2 arbitrary points in my model can I use the displacement results?

    • FAQFAQ
      Participant

      In random vibration,, since the results from the solver are statistical in nature they cannot be combined in the usual way. In random vibration, the displacement is a statistical Gaussian distribution with zero mean, so any location can move x-sigma displacement (usually either 1- or 3-sigma) in either the +/- direction. We do not know the phase of the motions, just statistically how much displacement occurs +/- of a mean zero. The calculated values are always reported as positive. By assuming various +/- values, we can calculate the maximum relative displacement that can statistically occur between two points. We cannot confirm that it does occur. So there is no way to use the random vibration displacements of two points to get an exact relative displacement.