Hi all,

The question: I now have a cylindrical piece of specimen to be modeled using axisymmetric model. In this case, should I fix both U1 and UR3 degrees of freedom for the nodes on the symmetric axis?

My thoughts: I read on Abaqus documentation, "Getting Started with Abaqus", 10.7 Example: axisymmetric mount. It says,:

"The axisymmetric nature of the model does not allow the structure to move as a rigid body in the radial direction. Abaqus will allow nodes to move in the radial direction, even those initially on the axis of symmetry (i.e., those with a radial coordinate of 0.0), if no boundary conditions are applied to their radial displacements (degree of freedom 1)."

From this I guess only U1 needs to be fixed, because UR3 is automatically constrained by the axisymmetric model by definition. However, I am not sure about this; any confirmation would really be appreciated.

Also, in the paragraph I cited, what does it mean by "move as a rigid body"? I originally thought the "rigid body movement" refers to translation and rotation, however there may be translation and rotation in axisymmetric situations... isn't it?

Thanks!

-Shawn