Effective Properties of Periodic Structures

Sometimes, you need to model on different scales. The heterogeneous micromechanics material properties cannot be directly used in the macroscopic scale in which the structure is to be analyzed. In such a case, you typically want to use a homogeneous material model with appropriate average properties.

The Cell Periodicity feature facilitates the evaluation of such average properties. It is based on the idea of a representative volume element (RVE). The RVE is a domain which contains a representation of the material in the microscale.

If the material is truly periodic, the RVE typically is the smallest possible unit cell. If the material has a random distribution of for example porosities, the RVE should be large enough to be representative for the average properties of the material on a macro scale.

The only requirement on the shape of the RVE is that it should be possible to fill space with a repetitive pattern of RVEs. This means that there are a set of matching boundary pairs, each pair having the same geometry, but offset by a given distance.