Map contact forces form Radioss to Optistruct

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

Hi,

 

how to map contact forces from Radioss solver to Optistruct solver and need to do Fatigue analysis by using those contact forces.

 

 

Regards,

Narasimhamurthy

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Answers

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited February 2020

    Hi,

     

    to extract the contact forces from Radioss simulation and use them in Optistruct follow the procedure from the attached reference (page 32):


    • Identify the time of contact force peaks by requesting /TH/INTER contact interface output block and postprocessing in Hypergraph.
    • Define /ANIM/VECT/CONT output request and query the contact forces on nodes of interest at the time of contact force peaks in Hyperview. Export the data in csv file format.
    • Import the contact forces in Optistruct by Analysis>forces>linear interploation>file
  • narasimhamurthy
    narasimhamurthy Altair Community Member
    edited February 2020

    Thank you, 

     

    Tried this method. extracted contact force from Hyperview as shown in below picture.

     

    image.png.d54b27be499f6a90bca282fabd375a67.png

     

    force created by using linear interpolation option. but handle showing different values and direction.

    <?xml version="1.0" encoding="UTF-8"?>image.thumb.png.a6164d14a69cc420ef5628840694a667.png

     

     

    will it make peak force to average force depend on number for nodes? how to change direction of force?

  • Simon Križnik
    Simon Križnik Altair Community Member
    edited February 2020

    Glad to help.

     

    Extract the contact force vector (three components) instead of contact contour. Request contact vector output by eng/anim/vect flags CONT and PCONT.

     

    The linear interpolation rules for input files have been changed (no comma allowed, separated by space or tab, only 3 coordinate components followed by vectors components): 

    <?xml version="1.0" encoding="UTF-8"?>lininterp.jpg

    for example:

     

    Node Coordinates  Vector(Contact Forces) 

    6647.1 -713.206 123.638   1.136E+01 -2.499E+00 -1.107E+01 

     

     

    Interpolation works best when the source mesh is geometrically similar to the target mesh.