Frozen areas are used to exclude the so-called frozen elements from being modified during the optimization, even though these elements are included in the design space. This is the case, e.g., when the elements are used in order to fix the component and therefore should be preserved independently of their internal loads. The inclusion into the design space may be necessary, e.g., to control the target volume (see constraints "absolute volume" or "relative volume", Bd.1, Chapter 5.5.1). | |||||||||