In shape optimization, the surface of a component is modified.
If only the surface nodes are displaced and the inner nodes remain at
their location, the surface layer elements are strongly distorted.
Therefore, the quality of the FE calculation suffers and might no longer
form a reliable basis for the optimization. To ensure realistic and
high-quality results, a displacement of the surface usually necessitates
a mesh displacement (mesh smoothing) in the inner of the structure in
most cases.