MAT2PT

Bulk Data Entry Defines anisotropic permittivity and damping for dielectric materials

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)
MAT2PT	`MID`	`PMTVXX`			`PMTVYY`		`PMTVZZ`	`DAMP`
	`FLAG1`	`FLAG2`

(1)	(2)	(3)	(4)	(5)	(6)	(7)	(8)	(9)	(10)
MAT2PT	17	0.1			1.5		0.01
	STRSCHG	RELATIVE

Field	Contents	SI Unit Example
`MID`	Unique material identification number. No default (Integer > 0)
`PMTVXX`	Defines the permittivity along the X direction. No default (Real > 0.0)
`PMTVYY`	Defines the permittivity along the Y direction. Default = `PMTVXX` (Real > 0.0)
`PMTVZZ`	Defines the permittivity along the Z direction. Default = `PMTVXX` (Real > 0.0)
`DAMP`	Damping term corresponding to the static electrical part. Default = 1.0 (Real ≥ 0.0 and ≤ 1.0)
`FLAG1`	Flag to indicate the form of `PMTVij` coefficients. 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 can be the shared with structural materials (MAT1, MAT2, MAT8, MAT9 or MGASK), thermal materials (MAT4, MAT5), or electrical materials (MAT1EC, MAT2EC) but must be unique with respect to other dielectric materials (MAT1PT).
MAT2PT is supported only for solid elements.
The electrical permittivity matrix has the following form:(1)
$[ε_{S}] = [\begin{matrix} ε_{x x} & 0 & 0 \\ 0 & ε_{y y} & 0 \\ 0 & 0 & ε_{z z} \end{matrix}] = [\begin{matrix} ε_{0} ε_{r x x} & 0 & 0 \\ 0 & ε_{0} ε_{r y y} & 0 \\ 0 & 0 & ε_{0} ε_{r z z} \end{matrix}]$
Where,

$ε_{0}$

Vacuum permittivity

$ε_{r x x}$

Relative permittivity defined by PMTVXX

$ε_{r y y}$

Relative permittivity defined by PMTVYY

$ε_{r z z}$

Relative permittivity defined by PMTVZZ

When FLAG=STRNCHG, the electrical permittivity matrix is expressed as:(2)
$[ε_{T}] = [\begin{matrix} ε_{0} ε_{r x x} & 0 & 0 \\ 0 & ε_{0} ε_{r y y} & 0 \\ 0 & 0 & ε_{0} ε_{r z z} \end{matrix}]$
The $[ε_{T}]$ matrix is converted to the $[ε_{S}]$ matrix by:(3)
$ε_{S} = ε_{T} - d c_{E} d^{T}$
Where,

$c_{E}$

Elastic matrix

$d$

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