The Symmetry node adds a boundary condition that represents symmetry in the geometry and in the loads. A symmetry condition is free in the plane and fixed in the out-of-plane direction.

When the model is axisymmetric, use the Symmetry Plane node instead.

The Symmetry node is only available with some COMSOL products (see http://www.comsol.com/products/specifications/).

This section is only present in the in the Layered Shell interface, where it is described in the documentation for the Symmetry node.

From the drop-down 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 button () and select Advanced Physics Options.

 Solid Mechanics>More Constraints>Symmetry
Layered Shell>More Constraints>Symmetry
 Membrane>More Constraints>Symmetry

Physics tab with Solid Mechanics selected:
Boundaries>More Constraints>Symmetry

Physics tab with Layered Shell or Membrane selected:
Edges>More Constraints>Symmetry