Add an Effective Material node () under a Materials node in a model component to define a material composed of two or more immiscible constituents. Instead of resolving the exact position in space of each constituent, they are approximated by their volume fraction, and the effective properties of the material are obtained from a set of mixing rules.

The Effective Material node is similar to the Multiphase Material node, with the exception that it contains Constituent (Subnode) instead of Phases and that it includes special mixing rules for composite materials.