Dynamic stiffness analysis

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hi all,

 

i need to calculate a dynamic stiffness in a frequency response analysis.

 

The term stiffness is defined as follows:

 

i have a structure (free from RB-modes) and i put a force load on a node in it, which must vary sinusoidal with time. The force load will deform the structure and i want to monitor the deformation of a certain node in the structure, which lies a distance away from the load point. The stiffness now is calculated as force / displacement.

 

What i need for postprocessing is the stiffness-value described above plotted over a frequency domain for the force of about 50 Hz to 10 kHz. Is that possible in RADIOSS Bulk? How do i model the loading? Which Output requests will deliver the needed values from the Solver?

 

Many thanks in advance

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Answers

  • Bhoopal
    Bhoopal New Altair Community Member
    edited November 2019

    Hi Florian_lw

     

    Good day,

    Your post was years ago, hope you might have extracted the dynamic stiffness from the frequency response analysis.

    From my point, I just came across this problem to find the dynamic stiffness from FRA. I have done a 1N load excitation at the base state & response of displacement at intended points noted over required frequency range. A 1 N unit load divided with the displacements will give the stiffness across the frequency range. The minimum the displacement, maximum will be the Dynamic stiffness in that particular direction. Hope I answered your query,

     

    I heard that in Radioss, there is a Channel method to extract dynamic stiffness, Can anyone please share the info., on it.

     

    PS: Better LATE than NEVER ... :)/emoticons/default_smile.png' srcset='/emoticons/smile@2x.png 2x' title=':)' width='20' />

     

    Thanks 7 regards,

    Bhoopal

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