Symmetry
The Symmetry node adds a boundary condition where there is symmetry in the pressure and displacement field. Use this condition to reduce the size of a model by cutting it in half where there are symmetries. Additional options apply to the displacement field normal component.
Normal Direction Condition
You can allow a symmetry plane to move along its normal direction. This can be used to model situations where you want a plane to remain strictly planar but still relax the property of it being fixed.
From the list, select No displacement (the default), Free Displacement, Prescribed force, or Prescribed displacement.
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The value No displacement gives a standard symmetry condition.
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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.
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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.
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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.
Constraint Settings
To display this section, click the Show More Options button () and select Advanced Physics Options in the Show More Options dialog.