# Piezoelectric Materials

## Definition

Piezoelectric material with losses.

## Description

The verification of the materials is not automatically done within the context of the ATILA-GiD interface. It is recommended to use CPIEZO from the ATILA supervisor to check the validity of piezoelectric materials.
Opening the piezoelectric materials dialog window may take a moment.

General
Symmetry Class |
Density | kg/m3

Mechanical
sE | Elastic compliance at constant Electric field | m2/N

Coupling
d | Piezoelectric constants | C/N

Dielectric
ET/E0 | Relative permittivity at constant stress |

Losses
Delta M | Mechanical loss angle
Delta P | Piezoelectric loss angle
Delta D | Dielectric loss angle
Check with CPIEZO

Magnetic
Relative magnetic permeability
Superpose magnetic domain to piezoelectric domain

## Illustration

## ATILA Implementation

- ATILA can use a different loss angle for every constant. In the interface, and as is usually done, we simplify this situation by using one loss angle per tensor.
- ATILA uses the absolute dielectric permittivity constants at constant strain (εS), therefore a transformation is made by the inteface.
- The dielectric loss angle (δd) is defined as the ratio of the imaginary to the real parts of the dielectric permittivities at constant stress.
- When the magnetic permeability is enabled, the mesh is "duplicated" so that a magnetic field computations can be performed on top of the elastic domain. Thus, both domains share the same nodes. This feature is typically used in magnetostrictive problems.

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