PSD definition

hiranwale_bharat
hiranwale_bharat Altair Community Member
edited October 2020 in Community Q&A

Hello,

 

I have PSD definition in terms of log g^2/hz instead of g^2/hz. What is the difference between these two? How should I give input for PSD? Will taking anti log of these values suffice?

 

Regards,

Bharat

Tagged:

Answers

  • Rahul Rajan_21763
    Rahul Rajan_21763 New Altair Community Member
    edited June 2016

    The below table should explain you to use the consistent units / conversion in RRA.

     

    PSD - Input

    Model - Units

    SPCD (FRF)

    PSD - Output

    RMS - Output

     

     

     

     

     

    G ^ 2 /Hz

    mm

    9810

    (mm/s2) ^2 / Hz

    mm/s2

    (mm/s2) ^2 / Hz

    mm

    1

    (mm/s2) ^2 / Hz

    mm/s2

    G ^ 2 /Hz

    mm

    1

    G ^ 2 /Hz

    G
  • hiranwale_bharat
    hiranwale_bharat Altair Community Member
    edited June 2016

    Hello Rahul,

     

    Thanks for replying. I knew about this conversion.What I would like to know is the difference between 'log value of g^2 / Hz' and 'g^2/hz' (i.e. no log value ).

     

    Will taking antilog values of log magnitude of g^/hz will give me 'regular' values of g^ /hz used in PSD?

     

    Regards,

    Bharat

Categories