need help answering the question below requires the knowledg

need help answering the question below requires the knowledge of SolidWorks please explain your answer
thanks

Explain why symmetry as well as anti-symmetry boundary conditions have to be used with caution in a frequency analysis.

Solution

Symmetry and anti-symmetry restraints:

In solid mechanics, the general rule for a symmetry displacement condition is that the displacement vector component perpendicular to the plane is zero and the rotational vector components parallel to the plane are zero. For an anti-symmetry condition the reverse conditions apply (displacements in the plane are zero; the rotation normal to the plane is zero).

For solid models using solid finite elements, the symmetry or anti-symmetry restraints are restricted to only translational displacements. This is because the solid models are modeled only with either TETRA4 (low) or TETRA10 (high) quality elements in COSMOS®, which do not have rotational degrees of freedom