Radial polarisation on sphere

Sneha

May 29, 2025 19:20

I don’t know, how to put radial polarisation on pzt sphere.please help me.

11 comments

Tapiwa Mutasa
May 30, 2025 11:18

Please use the axis option in the definition of radial poling. This article gives an example of how to do that.

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Sneha
May 30, 2025 14:49 (Edited May 30, 2025 14:51)

I read this article and tried in this way. but i got error like this when I preview the model

**** PZFlex has detected an error****

****Subroutines tracked are: pizinp jobctl flex

****Error occurred in subroutine pizinp ****

****Error message--data group member out of range

0 1030301

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Tapiwa Mutasa
May 30, 2025 15:11

Can you please show the formulation of the axis command

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Sneha
May 30, 2025 15:37

I modelled a PZT hollow sphere in OnScale designer mode and export model input.

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Tapiwa Mutasa
June 02, 2025 13:19
It does not appear that there is anything incorrect about your axis definition. However for the matr axis subcommand, you define thetabeg thetaend and ntheta, how e4ver you do not define phibeg phiend and nphi. The correct syntax of the command in the command reference is as follows:
```
axis matname axisname option thetabeg thetaend ntheta phibeg phiend nphi
```
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Tapiwa Mutasa
June 02, 2025 13:20

The error that you reference might be unrelated to the polarization. Can you confirm that this goes away with standard poling directions?

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Sneha
June 02, 2025 14:29 (Edited June 02, 2025 14:45)

Hello,

No. with standard poling directions, it run.

I want to simulate a pzt hollow sphere with radial polarization in OnScale. but i don't know how to create radial polarization on a sphere. Normally I have used x+,x-,y+,y-,z+ and z- polling options. I have read some articles regarding radial polarization on cylinders, etc. in the OnScale site. But i didn't get the exact idea. I am using OnScale designer mode.I modelled a PZT hollow sphere in OnScale designer mode and export model input. also, I would like to know if there are any options to see the polarization directions in Onscale after or before simulations to confirm whether it was made correctly or not. please consider it.

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Tapiwa Mutasa
June 02, 2025 15:24
You need to define phibeg phiend and nphi as in the command presented in the last message. If you are having issues you can reduce ntheta and nphi to 6 for example.

Regarding plotting, the example in the article plots the piezo electric materials with regions with different poling directions showing different colors. Alternatively, you can use the arrow subcommand of grph
```
grph
   type stnd
   arrow pole
   plot matr
   end
```
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Sneha
June 02, 2025 18:44

Can you please explain it with an example. I am using OnScale in designer mode only. OnScale analyst mode is not so familiar for me.

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Tapiwa Mutasa
June 02, 2025 19:52

Unfortunately, this cannot be done with Designer. You will have to use Analyst. You can generate Analyst script from Designer by clicking the "Save Solver Input" button. Please see the example below

mem 800 4000 /* Allocate 800 megawords of memory - 3 GigaBytes (Not necesarry for Windows Operating Systems)

c NOTE: MEM Command must be first command in file, if used. (Line 1)

rest no

c *************************************************************************************************************

c

c Generated Flex Input File

c

c *************************************************************************************************************

c

c DESIGNER :OnScale - Designer Generated

c MODEL DESCRIPTION :

c DATE CREATED :18 Jun 2019

c VERSION :1.0

c *************************************************************************************************************

mp

omp * * /* Number of CPUs to be used in the execution.

end

titl Example

c *************************************************************************************************************

c

c Define User Variables

c

c *************************************************************************************************************

c

c These variables have been set by the user through the interface.

c

c *************************************************************************************************************

symb coordFactor = 1.0 /* Coordinate conversion factor

symb timeFactor = 1.0 /* Time conversion factor

symb dMassFactor = 1.0 /* Mass conversion factor

symb freqint = 1e+6 /* Determined Drive Frequency (Hz)

c *************************************************************************************************************

c

c Define Meshing

c

c *************************************************************************************************************

c

c Set the variable for the approximate element size for the model. Must be

c sufficient to represent the wavelengths of interest. Recommended that at least

c 15 elements per wavelength are used.

c

c *************************************************************************************************************

symb freqdamp = $freqint

symb box = 0.02

c *************************************************************************************************************

c

c Geometry Locations (XYZ)

c

c *************************************************************************************************************

c Scale Parameters

symb xmin = -0.5 * $coordFactor

symb xmax = 0.5 * $coordFactor

symb ymin = -1.11022e-16 * $coordFactor

symb ymax = 1.0 * $coordFactor

symb zmin = -0.5 * $coordFactor

symb zmax = 0.5 * $coordFactor

c Determine lengths of the model

symb xlen = ( $xmax - $xmin )

symb ylen = ( $ymax - $ymin )

symb zlen = ( $zmax - $zmin )

c ***************************************************

c

c Keypoints in the X-Direction

c

c ***************************************************

symb #keycord x 1 $xmin $xlen

symb #get { idx } rootmax x

c ***************************************************

c

c Keypoints in the Y-Direction

c

c ***************************************************

symb #keycord y 1 $ymin $ylen

symb #get { jdx } rootmax y

c ***************************************************

c

c Keypoints in the Z-Direction

c

c ***************************************************

symb #keycord z 1 $zmin $zlen

symb #get { kdx } rootmax z

c *************************************************************************************************************

c

c Indices Locations (IJK)

c

c *************************************************************************************************************

c Grid in I direction, using approximately element size of 'box' and at least 1 element

symb #keyindx i 1 $idx 1 $box 1

symb indgrd = $i$idx

c Grid in J direction, using approximately element size of 'box' and at least 1 element

symb #keyindx j 1 $jdx 1 $box 1

symb jndgrd = $j$jdx

c Grid in K direction, using approximately element size of 'box' and at least 1 element

symb #keyindx k 1 $kdx 1 $box 1

symb kndgrd = $k$kdx

c *************************************************************************************************************

c

c GCON Grid & Geometry Allocation

c

c *************************************************************************************************************

grid $i$idx $j$jdx $k$kdx

geom

keypnt $idx $jdx $kdx

end

c --------------------------------------------------------------

c Project Material List

c --------------------------------------------------------------

c -------------------------------------------------------------------------

c Global variables used in all the material definitions

c -------------------------------------------------------------------------

c

symb epvacm = 8.854e-12 /* dielectric constant for vacumn

symb freqdamp = 1.e6 if noexist /* specified frequency for damping model

symb rmu0 = 1.2566e-6

symb #msg 5

********************************************************

Damping matched at $freqdamp Hz

Redefine variable 'freqdamp' if device centre frequency

varies significantly from this value

********************************************************

c

c -------------------------------------------------------------------------

c Now define the axis transformation - only posx used in this file

c -------------------------------------------------------------------------

axis

form vctr

defn posx car2 0. 0. 0. 1. 0. 0. 0. 1. 0.

defn negx car2 0. 0. 0. -1. 0. 0. 0. 1. 0.

defn posy car2 0. 0. 0. 0. 1. 0. 0. 0. 1.

defn negy car2 0. 0. 0. 0. -1. 0. 0. 0. 1.

defn posz car2 0. 0. 0. 0. 0. 1. 1. 0. 0.

defn negz car2 0. 0. 0. 0. 0. -1. 1. 0. 0.

form angl

defn cylnaxis cyln 0. 0. 0. 90. 0. 0.

defn sphraxis sphr 0. 0. 0. 90. 0. 0.

end

c -------------------------------------------------------------------------

c Input material properties to program

c -------------------------------------------------------------------------

matr

c --------------------------------------------------------------

c type : PIEZO :

c name : aln :

c desc : Aluminium Nitride - Thin film properties [1] from Sonitov Elastic and Piezoelectric Properties of AlN and LiAlO2 Single Crystals UFFC 2010 :

c --------------------------------------------------------------

c define baseline dielectric coefficients

symb epxx = 8.00000 /* dielectric constant (constant strain)

symb epyy = 8.00000 /* dielectric constant (constant strain)

symb epzz = 9.50000 /* dielectric constant (constant strain)

symb rho = 3260.00 /* density

symb qdmp = 10000.0 /* Mechanical Q at 1e6

symb qsdmp = 10000.0 /* Mechanical Q at 1e6

symb freqdamp = 1.e6 if noexist

symb freqloss = 2.00000e+09 if noexist /* Frequency that loss was measured at

c define baseline stiffness coefficients

symb c11 = 3.45000e+11 /* stiffness constant (constant electric field)

symb c12 = 1.25000e+11 /* stiffness constant

symb c13 = 1.20000e+11 /* stiffness constant

symb c14 = 0.00000 /* stiffness constant

symb c15 = 0.00000 /* stiffness constant

symb c16 = 0.00000 /* stiffness constant

symb c22 = 3.45000e+11 /* stiffness constant (constant electric field)

symb c23 = 1.20000e+11 /* stiffness constant

symb c24 = 0.00000 /* stiffness constant

symb c25 = 0.00000 /* stiffness constant

symb c26 = 0.00000 /* stiffness constant

symb c33 = 3.95000e+11 /* stiffness constant

symb c34 = 0.00000 /* stiffness constant

symb c35 = 0.00000 /* stiffness constant

symb c36 = 0.00000 /* stiffness constant

symb c44 = 1.18000e+11 /* stiffness constant

symb c45 = 0.00000 /* stiffness constant

symb c46 = 0.00000 /* stiffness constant

symb c55 = 1.18000e+11 /* stiffness constant

symb c56 = 0.00000 /* stiffness constant

symb c66 = 1.10000e+11

c define baseline piezoelectric coupling coefficients

symb ex1 = 0.00000 /* coupling constant

symb ex2 = 0.00000 /* coupling constant

symb ex3 = 0.00000 /* coupling constant

symb ex4 = 0.00000 /* coupling constant

symb ex5 = -0.480000 /* coupling constant

symb ex6 = 0.00000 /* coupling constant

symb ey1 = 0.00000 /* coupling constant

symb ey2 = 0.00000 /* coupling constant

symb ey3 = 0.00000 /* coupling constant

symb ey4 = -0.480000 /* coupling constant

symb ey5 = 0.00000 /* coupling constant

symb ey6 = 0.00000 /* coupling constant

symb ez1 = -0.580000 /* coupling constant

symb ez2 = -0.580000 /* coupling constant

symb ez3 = 1.55000 /* coupling constant

symb ez4 = 0.00000 /* coupling constant

symb ez5 = 0.00000 /* coupling constant

symb ez6 = 0.00000 /* coupling constant

c scale material properties as specified above

symb aepxx = $epvacm * $epxx

symb aepyy = $epvacm * $epyy

symb aepzz = $epvacm * $epzz

wvsp off

type lean

prop aln $rho

$c11 $c12 $c13 $c14 $c15 $c16 $c22

$c23 $c24 $c25 $c26 $c33 $c34 $c35

$c36 $c44 $c45 $c46 $c55 $c56 $c66

elec aln $aepxx $aepyy $aepzz

piez aln 1 1 $ex1 1 2 $ex2 1 3 $ex3 1 4 $ex4 1 5 $ex5 1 6 $ex6 &

2 1 $ey1 2 2 $ey2 2 3 $ey3 2 4 $ey4 2 5 $ey5 2 6 $ey6 &

3 1 $ez1 3 2 $ez2 3 3 $ez3 3 4 $ez4 3 5 $ez5 3 6 $ez6

rdmp aln $freqdamp q $qdmp $qsdmp $freqloss 1.0

c axis aln cylnaxis plusr 0. 360. 12. /* relate materials local system to global system

axis aln sphraxis plusr 0. 360. 36. 0. 360. 36.

elec void $epvacm

end

c *************************************************************************************************************

c

c Primitive Definitions

c

c *************************************************************************************************************

site

regn void

sphr aln 0.0 0.0 0.0 0.5 0.25

end

grph

plot matr

end

term

c *************************************************************************************************************

c

c Boundary Definitions

c

c *************************************************************************************************************

boun

side xmin free

side xmax free

side ymin free

side ymax free

side zmin free

side zmax free

end

piez

wndo * * * * * *

defn actv 0.5

nod2 root aln void

bc actv grnd

slvr pard

end

time * * 0.8

c *************************************************************************************************************

c

c Process Model

c

c *************************************************************************************************************

c

c Issue process (PRCS) command. Checks model integrity, and calculates stable

c time step. NOTE: Process command must always be issued

c

c *************************************************************************************************************

symb #msg 1

Checking Model Integrity......

prcs

grph

type stnd

arrow pole 5 5

plot matr

end

term

c *************************************************************************************************************

c

c Run the Model

c

c *************************************************************************************************************

c

c Specify the number of time steps to be run. Can be set to auto by using

c 'Ringdown'.

c

c *************************************************************************************************************

c User defined runtime for the model

symb #get { step } timestep

symb ttime = 0.001

symb nexec = $ttime / $step

exec $nexec

symb n_extra = nint ( $step / 10 )

exec $n_extra

term

data

file out 'Example.flxdato'

out modl

end

c *************************************************************************************************************

c

c Save symbol variables to file for later use

c

c *************************************************************************************************************

symb #get { labl } jobname

symb #save '$labl.symb'

stop /* return to command prompt

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Sneha
June 04, 2025 19:13

Hello.. I tried in this way. The radial polarisation on sphere is done . But the problem is when I add water domain( cube) around the sphere, put absorbing boundary conditions and chosen extrapolation output, It didn’t run, I could apply radial polarisation, only when simulating pzt hollow sphere alone.

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