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Extracting beam forces in random vibration

    • brian.keats
      Subscriber

      I'm running a random vibration analysis, and modelling my bolts as beam elements. I need to extract the beams forces (preferably in the beam coordinate systems so I can split out axial and shear forces). There doesn't seem to be an out-of-the-box way to do this. Does anyone have any insight on how I might get this done? 

      I found this resource that allows me to extract beam forces in eather globa coordinates, or just the axial force in beam coordinates (I also need the shear).

      https://simutechgroup.com/retrieve-beam-reaction-forces-in-random-vibration-analysis/

      Is there a better approach than this? I'm transitioning to Ansys from an NX/NASTRAN background and I'm a bit shocked there's no native way to extract nodal or element forces.

    • Aniket
      Forum Moderator

      Would user-defined result as follows help?

      -Aniket

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    • brian.keats
      Subscriber

      That looks promising! I'm having a couple of issues.

      When I select an edge associated with the beam element, I get the error that I need valid scoping.

      If I curcumvent the scoping issue by scoping to element ID, I get the error that "A result is invalid with the current output control settings". Modal and random output settings are shown below. I have nodal forces enabled.

      Any insight on how I can fix the above two issues?

    • Aniket
      Forum Moderator

      Are you modeling beams a line bodies? You will need to have line bodies in order to this to work.

      -Aniket

      How to access Ansys help links

      Guidelines for Posting on Ansys Learning Forum

    • brian.keats
      Subscriber

      I want to maintain connectivity to my solidworks model. I would have to break that to create line bodies. Is there a way I can use this approach without line bodies? If I include the fastener solid bodies, can I associate a beam mesh with the fastener geometry and use this approach?

    • brian.keats
      Subscriber

      Never mind, I figured it out. I had to change scoping method to results file item, item type to element name IDs, and leave the default 'All' for solver component IDs and Golbal IDs.

    • brian.keats
      Subscriber

      I have one final issue. There doesn't seem to be a good way to display the node numbers for body-to-body beam connections. When I try to display the node numbers in 'Preferences Annotations' they don't show up. I can't select beam nodes in the display window to see the node number either. 

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