General Mechanical

General Mechanical

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how we can apply a follower load or nonconservative force in ansys ?

    • freud farid
      Subscriber

      i need to validate this benchmark "Large deflection of curved cantibver under nonconservative tangential end load" , as show in image bellow , the force R is nonconservative load that mean the force R remains normal to the mid-axis of the beam during deformation

      i need way to apply this kind of force in ansys ? 

    • peteroznewman
      Subscriber

      Here is the Ansys Help entry: 

      https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v231/en/ans_elem/Hlp_E_FOLLW201.html

      Here is an old discussion:

      /forum/forums/topic/how-to-setup-a-follower-force-for-a-cantilever-beam/

    • freud farid
      Subscriber

      this link not open 

      https://ansyshelp.ansys.com/account/secured?returnurl=/Views/Secured/corp/v231/en/ans_elem/Hlp_E_FOLLW201.html

      for the discussion , i have already read it , unfortunately It is useless

      There will remain a problem that needs to be answered by Ansys

    • Erik Kostson
      Ansys Employee

       

      Hi By default, Mechanical uses FOLLW201 element to apply a force to a BEAM element.

      Thus, follower effects are considered.

      All the best

      Erik

       

    • peteroznewman
      Subscriber

      First open Ansys Help.

      Copy the URL above and paste it into the Address bar of the browser showing Ansys Help.

      It will open.

    • freud farid
      Subscriber

      hi Erik Kostson

      how you get this information in image ? How can I access to switch between elements availables 

      how i can choose or apply  follw201 element ?

      but I don't get the same results as reference and analytical result

    • Erik Kostson
      Ansys Employee

      Hi

       

      Q: how you get this information in image ?

      Go to Solution in the mechaniacl tree, right mouse button click and choose Worksheet Res. Summary (see below).

      Q: how i can choose or apply  follw201 element ?

      As I said when we apply a force in mechanical on a line body (which is meshed with beam elements), automatically the follw201 elements are created by Mechanical and used, hence follower effects are considered.

      All the best

       

      Erik

      • freud farid
        Subscriber

        It still gives me either  beam188 when i use line sketch or solid186 when i use solid

        I don't know where the problem is ? 

        i find extension in site  for applaying 'follower load' but i didn't know how to apply it
        How do I contact you privately?

    • peteroznewman
      Subscriber

      I tried a standard force applied to a beam 188 mesh, but the follower force is not created by default as can be seen by the Reaction Force.

      I used the Follower Force ACT to create a Follower Force. The Force Reaction shows that it is working.

      • Erik Kostson
        Ansys Employee

         

         

        It is because the native force object inside mech., that generates the folw201 elements in the ds.dat file, uses keyoption(1)=1 – so not to update the direction.

        We need a command to activate the update direction (below the type id is 2 for the follw201 element and typed id 1 for beam188):

        All the best

        Erik

         

         

         

        • freud farid
          Subscriber

          Erik 

          can you share in detail steps to do that ? i need to do this example in follower force for my master project , I desperately need help

    • peteroznewman
      Subscriber

      Erik, I see what your original point was now that I opened the ds.dat input file and found an element type 201 for the follower element and the keyop,3,1,1 to keep the direction from changing!

      /com,*********** Create Remote Point "Remote Force - Remote Point" ***********
      *set,_npilot,74
      _npilot50=_npilot
      et,2,170
      type,2
      real,2
      mat,2
      keyo,2,2,1              ! don't fix pilot node
      keyo,2,4,111111
      tshape,pilo
      en,38,74        ! create pilot node for rigid link
      tshape
      en,39,74,1
      /com,*********** Define Vertex Force Using Follower Elements ***********
      et,3,201
      keyo,3,1,1           ! Keep the direction constant
      keyo,3,2,1           ! Apply Forces only, not moment
      mat,3
      real,3
      type,3
      en,40,1
      r,3
      rmod,3,1,1.0,              ! FX
      mat,4
      real,4
      type,3
      en,41,1
      r,4
      rmod,4,2,1.0,              ! FY
      mat,5
      real,5
      type,3
      en,42,1
      r,5
      rmod,5,3,1.0,              ! FZ
      /gst,on,on
      fini

      In this model, the type ID for the FOLLW201 element is 3 so the Keyops are as shown below.

      Thank you for the help Erik!

      • freud farid
        Subscriber

        thank you for sharing the code , but when i use it not work and give error

        please can you share the result of y displacement ?

        can you show the detail by image how to apply follower load in example above ?

        thank you 

    • Erik Kostson
      Ansys Employee

      All the best Peter.

      Erik

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