MAT1PT

Note: This can be used along with the MATPZO Bulk Data Entry for defining piezoelectric coupling.

Format


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MAT1PT	`MID`	`PMTV`					`DAMP`
	`FLAG1`	`FLAG2`


(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MAT1PT	17	0.1					1.2
	STRNCHG	RELATIVE


Field	Contents	SI Unit Example
`MID`	Unique material identification number. No default (Integer > 0)
`PMTV`	Defines the permittivity. No default (Real > 0.0)
`DAMP`	Damping term corresponding to the dielectric term. No default (Real > 0.0)
`FLAG1`	Flag to indicate the form of definition. STRNCHG (Default) Indicates STRAIN-CHARGE form STRSCHG Indicates STRESS-CHARGE form
`FLAG2`	Flag to indicate type of permittivity. ABSOLUTE (Default) Absolute permittivity RELATIVE Relative permittivity In this case, vacuum permittivity also needs to be provided by PARAM, VAPMTV.

The material identification number/string may be the shared with structural material property definitions (MAT1, MAT2, MAT8, MAT9 or MGASK), thermal material property definitions (MAT4, MAT5), or electrical material property definitions (MAT1EC or MAT2EC) but must be unique with respect to other dielectric materials (MAT2PT).
MAT1PT is supported only for solid elements.
The material permittivity is obtained as:
$ε = ε_{0} ε_{r}$
Where,

$ε_{0}$

Vacuum permittivity

$ε_{r}$

Coefficient defined by PMTV

The permittivity matrix, in Stress-Charge form, is expressed as:
$[ε_{S}] = [\begin{matrix} ε_{0} ε_{r} & 0 & 0 \\ 0 & ε_{0} ε_{r} & 0 \\ 0 & 0 & ε_{0} ε_{r} \end{matrix}]$
When FLAG=STRNCHG, Strain-Charge form is defined in the card, and the permittivity matrix is expressed as:
$[ε_{T}] = [\begin{matrix} ε_{0} ε_{r} & 0 & 0 \\ 0 & ε_{0} ε_{r} & 0 \\ 0 & 0 & ε_{0} ε_{r} \end{matrix}]$
The $[ε_{T}]$ matrix is converted to $[ε_{S}]$ matrix by:
$ε_{S} = ε_{T} - d c_{E} d^{T}$
Where,

$c_{E}$

Elastic matrix

$d$

Piezoelectric coupling matrix defined in MATPZO
For more information, refer to Piezoelectric Analysis in the User Guide.