# Boundary Conditions: Polarization

## Function:

Defines the crystal orientation of piezoelectric and magnetostrictive regions.

## Application:

Surface, Volume.

## Description:

A polarization is defined with respect to a local coordinate system (Local Axes).
Three polarizations can be defined: Cartesian, Cylindrical, Spherical.
- Cartesian: The polarization is uniform in the region. It is oriented in the z direction of the local coordinate system. The center of the coordinate system has no importance.
- Cylindrical: The polarization is cylindrically radial with respect to the z axis of the local coordinate system.
- Spherical: The polarization is spherically radial and is centered at the local coordinate system.

## Remarks:

- Additional details are provided in the help and example files.
- An additional "delta" angle can be defined within ATILA, but it is not taken into account in the interface, yet.

## Illustration:

## ATILA Equivalent:

In all cases, it is an entry in the GEOMETRY POLARIZATION section, with the CARTESIAN, CYLINDRICAL, or SPHERICAL option. Details about angles and definition parameters should be looked up in the ATILA User's Manual. Note that the convention for Euler angles is not the same in GiD and ATILA.

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