The Symmetry Plane node adds a boundary condition that represents symmetry in the geometry and in the loads. This node is available only in 2D axisymmetry, where the only possible symmetry plane is normal to the Z-axis.

This section is shown only if Include circumferential displacement has been selected in the settings for a Solid Mechanics node.

Select either Symmetry or Antisymmetry.

With the symmetric assumption, the solution for the circumferential displacement is v(R, 2Zp-Z) = v(R, Z), where Zp is the location of the symmetry plane.

With the antisymmetric assumption, an extra constraint v=0 is added in the symmetry plane, giving a solution for the circumferential displacement of the type v(R, 2Zp-Z) = -v(R, Z). This makes it possible to model a structure that is geometrically symmetric, but subjected to a twisting state of deformation.

From the list, select No displacement, Free Displacement, Prescribed force, or Prescribed displacement.

The value No displacement gives a standard symmetry condition.

Select Free Displacement to allow the symmetry plane to translate in the normal direction. The displacement is determined by the criterion that there is no resulting reaction force in the normal direction.

Select Prescribed force to prescribe the total reaction force acting on the direction normal to the symmetry plane. Enter the Normal force Fn. The force is defined as positive when acting along the outward normal of the symmetry plane. Setting the prescribed force to zero gives the same effect as using Free Displacement.

Select Prescribed displacement to prescribe the displacement in the direction normal to the symmetry plane. Enter the Normal displacement un0. Setting the prescribed displacement to zero gives the same effect as using No displacement.

To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog box.

Physics tab with Solid Mechanics selected:

Physics tab with Membrane selected: