Contents     Functions              PDF Index

m_piezo

• [Database,Dbval] [-unit TY] [,MatiD]] Name
• Patch
• 1 : Simplified 3D piezoelectric properties
• 2 : General 3D piezo
• 3 : General 3D piezo, e matrix

Purpose

Material function for piezoelectric solids

Syntax

 mat= m_piezo('database name')
 pl = m_piezo('dbval MatId  -elas 12 Name');

See section 2 for tutorial calls. Accepted commands are

[Database,Dbval] [-unit TY] [,MatiD]] Name

m_piezo contains a number of defaults obtained with the database and dbval commands which respectively return a structure or an element property row. You can select a particular entry of the database with using a name matching the database entries.

Piezoelectric materials are associated with two material identifiers, the main defines the piezoelectric properties and contains a reference ElasMatId to an elastic material used for the elastic properties of the material (see m_elastic for input formats).

  m_piezo('info') % List of materials in data base
  % database piezo and elastic properties
  pl=m_piezo('dbval 3 -elas 12 Sample_ULB')

Theoretical details on piezoelectric materials are given in chapter 1. The m_piezo Const and BuildConstit commands support integration constant building for piezo electric volumes integrated in the standard volume elements. Element properties are given by p_solid entries, while materials formats are detailed here.

Patch

Supports the specification of a number of patches available on the market. The call uses an option structure with fields

• .name of the form ProIdval+patchName. For example ProId1+SmartM.MFC-P1.2814.
• MatId value for the initial MatId.

m_piezo('patch') lists currently implemented geometries. In particular

• Noliac.Material.Geometry is used for circular patches by Noliac. Fields for the geometry are
  • OD outer diameter (mm).
  • TH Thickness (mm). To specify a milimiter fraction replace the . by and _. For example TH0_7 is used for TH=0.7 mm.
  • ID inner diameter (mm) (optional for piezo rings).
• SmartM.Material.Geometry is used for circular patches by Noliac. The geometry is coded assuming a rectangle in mm. Thus 2814 corresponds to an 28 x 14 mm active rectangle.

The piezoelectric constants can be declared using the following sub-types

1 : Simplified 3D piezoelectric properties

[ProId Type ElasMatId d31 d32 d33 eps1T eps2T eps3T EDType]

These simplified piezoelectric properties (92) can be used for PVDF, but also for PZT if shear mode actuation/sensing is not considered (d₂₄=d₁₅=0). For EDType==0 on assumes d is given. For EDType==1, e is given. Note that the values of є^T (permitivity at zero stress) should be given (and not є^S).

2 : General 3D piezo

[ProId Type ElasMatId d_1:18 epsT_1:9]

d_1:18 are the 18 constants of the [d] matrix (see section 1.2.1), and epsT_1:9 are the 9 constants of the [є^T] matrix. One reminds that strains are stored in order xx,yy,zz,yz,zx,yx.

3 : General 3D piezo, e matrix

[ProId Type ElasMatId e_1:18 epsT_1:9]

e_1:18 are the 18 constants of the [d] matrix, and epsT_1:9 are the 9 constants of the [є^T] matrix in the constitutive law (see section 1.2.1).

See also

p_piezo.