Batosai
Automotive
- May 24, 2012
- 4
My 3D simulation is really complex but the problem I'm facing now could be solved if I could resolve this simple problem first: (Working with classical ANSYS)
Imagine a beam element conecting 2 nodes.
1*------------*2
I create a local cylindrical co-ord system at node 1. Which is R,θ,Z. Where θ is Y.
I rotate node 2 to that local co-ord system with NROTAT.
I want to rotate node 2 with node 1 being the centre of rotation, but I don't want to fix the radial displacement, only angular displacement.
In ANSYS Uθ is not in radians, is in longitude units as it refers to the tangential displacement counting from the first position of the node and being this longitude in the perpendicular direction of the line between node 1 and 2. In the example above it would be the same as the vertical cordinate.
The problem comes when you want to rotate node2 90 or more degrees. Have you done that?
What I've tried so far:
Dividing the problem in multiple Loadsteps, but since in ANSYS displacements are all refered to the beginning position, I haven't worked. Even tried to move 90 degrees using multiple LoadSteps and then apply displacement in the UX direction (As tangential and radial direction have changed they meaning when you reach that point because of the way they are defined) --> Haven't worked, not even a single substep.
Reach the 90 degrees point and then try to refresh the local coordinate system or Aplying NROTAT with another co-ord system. But then I can't restart another substep as the model has changed to ANSYS.
ETC.
Thank you very much for your help.
Imagine a beam element conecting 2 nodes.
1*------------*2
I create a local cylindrical co-ord system at node 1. Which is R,θ,Z. Where θ is Y.
I rotate node 2 to that local co-ord system with NROTAT.
I want to rotate node 2 with node 1 being the centre of rotation, but I don't want to fix the radial displacement, only angular displacement.
In ANSYS Uθ is not in radians, is in longitude units as it refers to the tangential displacement counting from the first position of the node and being this longitude in the perpendicular direction of the line between node 1 and 2. In the example above it would be the same as the vertical cordinate.
The problem comes when you want to rotate node2 90 or more degrees. Have you done that?
What I've tried so far:
Dividing the problem in multiple Loadsteps, but since in ANSYS displacements are all refered to the beginning position, I haven't worked. Even tried to move 90 degrees using multiple LoadSteps and then apply displacement in the UX direction (As tangential and radial direction have changed they meaning when you reach that point because of the way they are defined) --> Haven't worked, not even a single substep.
Reach the 90 degrees point and then try to refresh the local coordinate system or Aplying NROTAT with another co-ord system. But then I can't restart another substep as the model has changed to ANSYS.
ETC.
Thank you very much for your help.