General Mechanical

General Mechanical

Nodal angular displacements

    • Zainaba98
      Subscriber

      Hi everyone,

      I'm new to Ansys and have the following problem.

      [Please see attached video for graphical aid]

    • peteroznewman
      Subscriber
      Nodes connected to solid elements do not have rotational degrees of freedom, which is why the values are always zero. That is normal.
      Nodes connected to shell or beam elements have rotational degrees of freedom.
      In order to track the rotation of the end face of the solid beam, you need to attach a Remote Point, type = Deformable, to that face. That will put a pilot node at the center of the face that will interpolate the motion of all the nodes on that face and report deformation in six degrees of freedom.
      I see you are using ANSYS 19.2.
      Have you tried to insert a Flexible Rotation Probe?
      https://forum.ansys.com/discussion/1163/measuring-rotation-in-ansys-mechanical-application-workbench
    • Zainaba98
      Subscriber
      Thank you so much for the reply. Yes I did try a flexible rotation probe but it didn't work to measure angular displacements of nodes.
      However, I tried adding a remote point and I have a few questions in this regard:
      1- If I associate the remote point to a node, it gives me zero angular displacements. However, if I assign it to multiple nodes belonging to the same face it gives me a non-zero number (however one which is very big). Is this normal?
      2- When I assign a remote point to a face, what it measures is the average of angular displacements of all nodes of that face. am I right?
      3- When I use the remote point to measure the angular rotation, it gives me a single value for each rotation about each axe although I have several loads applied over 100seconds. I am assuming that's giving me the final angular displacement, i.e. that at time=100s. Is there any online code to get the angular displacements of each face at all laoding times (t=1s -> t=100s)? I tried to search online for something as such but it was in vain.
      Thanks again.
    • peteroznewman
      Subscriber
      Yes, that is normal because one node on a solid element has no rotational degrees of freedom so the answer is zero, but three non-colinear nodes can have a measurable angular displacement.
      There are two behaviors that you can set for a Remote Point: Deformable and Rigid. Deformable is interpolating the average motion of all nodes. Rigid creates a rigid body connected to those nodes so they all move as one and stiffness is added to the model.
      How do you measure the angular rotation of the remote point? If you have multiple steps in the solution, you can show results at the end of each step, doesn't that work? Insert screen images.
      The flexible rotation probe is using a remote point to output the rotation. What do you mean it didn't work? Insert screen images.
    • Zainaba98
      Subscriber
      Thank u so much, it worked out just fine
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