Can anyone guide me how to mesh solid and shell 3d hemisphere with hex dominant approach in ansys mechanical APDL?
I found no such verification manual for 3d hemispherical meshing in ansys. What method should be applied and what element should be chosen appropriately to mesh this structure?
I have attached screen shot for your understanding of my problem.
Your response will be highly appreciated.
You can also post your reply or private
Thanking you in advance
Firstly, do for quater model. Try to use mapped mesh by concatenate command. For example, vmesh need to do area concatenate to be 6 sides of area for brick shape.
Hi,
I hope the attached script can be helpful.
It is for a surface, but it can be taken as an example for the volume case
(maybe a simple areas or mesh sweeping in a spherical reference system would do the job, otherwise you should re-do everything in terms of volumes).
The sphere is partitioned in such a manner that only quadrilateral elements are used (see the attached png file).
Caveat: there are some warnings but the final result seems to be OK. Anyway, please, check it carefully.
Here the APDL script:
finish
/clear
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! PARAMETERS !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! GEOMETRY
*set, r, 0.2
*set, perc_r, 0.50
*set, thickness, 0.001
!
! MESH
*set, ele_numb_rad_dir, 5
*set, ele_numb_circ_dir, 10
!
! MATERIAL
*set, E, 130000.
*set, nu, 0.33
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! SETTINGS !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
/pnum, kp, 1
/pnum, line, 1
/pnum, area, 1
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! PREPROCESSING !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
/PREP7
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! MATERIAL !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
mptemp,,,,,,,,
mptemp, 1, 0
mpdata, ex, 1, , E
mpdata, prxy, 1, ,nu
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! GEOMETRY !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
k, 1, 0, 0, 0
k, 2, 0, -r, 0
circle, 1, r, 2, , 90, 1
arotat, 1, , , , , , 1, 4, 45
nummrg, all, , , , low
k, 6, perc_r*r, 0, 0
k, 7, perc_r*r, 0, 2*r
k, 8, 0, perc_r*r, 0
k, 9, 0, perc_r*r, 2*r
l, 6, 7
l, 7, 9
l, 8, 9
l, 8, 6
al, 4, 5, 6, 7
asba, 1, 2
numcmp, all
lesize, 5, , , ele_numb_circ_dir
lesize, 6, , , ele_numb_circ_dir
lesize, 1, , , ele_numb_rad_dir
lesize, 4, , , ele_numb_rad_dir
cskp, 11, 0, 1, 5, 4, 1, 1
csys, 11
arsym, z, all, , , , 0, 0
nummrg, all, , , , low
csys, 0
arsym, x, all, , , , 0, 0
nummrg, all, , , , low
arsym, y, all, , , , 0, 0
nummrg, all, , , , low
!
adele, 3
adele, 7
al, 3, 9, 18, 7
ldele, 8
!
adele, 1
adele, 9
al, 17, 21, 4, 3
ldele, 2
!
adele, 11
adele, 15
al, 29, 35, 26, 17
ldele, 25
!
adele, 5
adele, 13
al, 31, 29, 7, 13
ldele, 11
nummrg, all, , , , low
lesize, 3, , , ele_numb_rad_dir
lesize, 7, , , ele_numb_rad_dir
lesize, 29, , , ele_numb_rad_dir
lesize, 17, , , ele_numb_rad_dir
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! MESHING !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
et, 1, shell281
keyopt, 1, 1, 0
keyopt, 1, 8, 0
keyopt, 1, 9, 0
keyopt, 1, 10, 0
r, 1, thickness
amesh, all
nummrg, node, , , , low
numcmp, all
eplot
! CHECKING FOR MESH GAPS
!/edge, 1, 1
!/device, vector, 1
!
/eof
Best,
Gaetano
Hello
Gaetano's answer is quite accurate. The ANSYS apdl meshing module is not too powerful, generally having problems when meshing with hexa elements.
A common solution is to divide the surface you are working with into surfaces that can be meshed. For example any surface that could be obtained from an extrusion can be sweep meshed.
Also another option is to help the mesher by defining the element sizes, number or elements per section, etc.
A the 3D hex mesh can be obtained also by meshing a surface with quads and then followed by an extrusion. You must specify a volumetric element and the divisions.
In this way you may avoid some problems regarding the aspect ratio, because the quad mesh is not necessary to be mapped (you can use smart mesh with quad option). Even more, you can insert regions on your spherical surface where the mesh to be denser, if you wish.
Wishing you the best,
Victor
Hi. I'm doing simulation on Ansys APDL regarding cricket ball. I'm new to Ansys and the problem I had is to mesh the sphere. Apparently the step is "by dividing the sphere into 8 parts and mesh them one by one and then glue them together."
If anyone willing to guide me a step by step procedure to mesh this sphere problem it will be much appreciate.
For a voice-over Power Point Video on, "The Finite Element Method"; which can be DOWNLOADED by Clicking the URL below; but be patient, because it is being downloaded into your folder:
http://dl.dropbox.com/u/39907336/THE%20FINITE%20ELEMENT%20METHOD-06-02-2012._1.avi
For Stresses in a Plate with a Hole in it; Using ANSYS; CLICK:
http://youtu.be/_VZaVc73UOA
For Vibrations using ANSYS; CLICK:
http://youtu.be/USVi8XCva0c
For Buckling using ANSYS; CLICK:.
http://youtu.be/aDTAnimUVvs
Buckling & Vibration of a Composite Submarine Pressure Hull; Using ANSYS.
a) Buckling.
Buckling of a Composite Submarine Hull Using ANSYS; CLICK:
https://dl.dropbox.com/u/39907336/BucklingCompSub_ANSYS_Mp4.mp4
b) Vibration of a Composite Submarine Hull Using ANSYS; CLICK:.
http://www.youtube.com/watch?v=ZLf2VET_FnU&feature=youtu.be
Vibration of a Ring-Stiffened Conical Shell, Using ANSYS; CLICK:
https://dl.dropbox.com/u/39907336/VibRingCone_ANSYS_09-03-3012.wmv
For Elastic (Eigen) Buckling of a Conical Shell under Lateral Pressure. Using ANSYS; CLICK:
http://youtu.be/_T90vo42UTE
For NonLinear Buckling of a Conical Shell Under Lateral Pressure__A Complete SUCCESS! CLICK:
http://www.youtube.com/watch?v=Qnre1ss8LZI&feature=youtu.be
Dear Sunandar ·,
try the following script.
I work on 1/8th of the model. I partition it so that I can have a regular mesh (see first fig.).
Then, I reflect everything versus the three Cartesian planes to have the whole sphere (see second fig.).
I hope it is useful.
The code follows:
finish
/clear
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! PARAMETERS !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
! GEOMETRY
*set, r, 1.
*set, perc_r, 0.40
!
! MESH
*set, ele_numb_cube, 10
*set, ele_numb_rad, 10
!
! MATERIAL
*set, E, 130000.
*set, nu, 0.33
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! SETTINGS !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
/pnum, kp, 1
/pnum, line, 1
/pnum, area, 1
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! PREPROCESSING !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
/PREP7
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! MATERIAL !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
mptemp,,,,,,,,
mptemp, 1, 0
mpdata, ex, 1, , E
mpdata, prxy, 1, ,nu
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! GEOMETRY !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!
sphere, 0, r, 0, 90
rectng, 0, 2*r, 0, 2*r
vsba, 1, 4
vdele, 2, , , 1
agen, 2, 9, , , , , , , 0
vdele, 3, , , 1
block, 0., perc_r*r, 0., perc_r*r, 0., perc_r*r
aplot
!lang, 1, 11, 90
lang, 5, 4, 90
!lang, 3, 9, 90
k, 15, 2*r/2., 2*r/2., 2*r/(2.**0.5)
l, 10, 15
k, 16, kx(15), 0., kz(15)
k, 17, 0., ky(15), kz(15)
l, 9, 16
l, 16, 15
al, 9, 18, 20, 19
asba, 8, 1, , , keep
adele, 10
ldele, 20
ldele, 24, 25, 1
kdele, 16
l, 15, 17
l, 11, 17
l, 10, 15
al, 10, 20, 18, 19
asba, 8, 1, , , keep
adele, 11, , , 1
csys, 2
l, 12, 16
csys, 0
l, 5, 7
l, 1, 2
l, 6, 8
lsel, s, line, , 18
lsel, a, line, , 23, 26, 3
asbl, 1, all
allsel, all
al, 11, 25, 32, 27
al, 8, 27, 31, 21
asel, s, area, , 1, 3, 2
asel, a, area, , 9, 10, 1
asel, a, area, , 12, 13, 1
nummrg, all, , , , low
va, all
allsel, all
!
al, 17, 14, 22, 18
al, 6, 17, 5, 19
al, 21, 28, 19, 13
asel, s, area, , 7, 9, 1
asel, a, area, , 14, 16, 1
va, all
allsel, all
!
al, 25, 30, 20, 15
al, 4, 17, 16, 20
asel, s, area, , 5, 10, 5
asel, a, area, , 11, 14, 3
asel, a, area, , 17, 18, 1
va, all
allsel, all
nummrg, all, , , , low
!
!
!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
!!! MESHING !!!
!!!!!!!!!!!!!!!!!!!!!!!!!!!!
et, 1, solid186
keyopt, 1, 2, 0
keyopt, 1, 3, 0
keyopt, 1, 6, 0
keyopt, 1, 10, 0
!
!
vsel, s, volu, , 1
aslv, s
lsla, s
asel, s, area, , 8
asel, a, area, , 11, 12, 1
lsla, a
lesize, all, , , ele_numb_cube
lsel, inve
lesize, all, , , ele_numb_rad
allsel, all
vmesh, all
nummrg, all, , , , low
numcmp, all
vsymm, x, all, , , , 0, 0
vsymm, y, all, , , , 0, 0
vsymm, z, all, , , , 0, 0
nummrg, all, , , , low
numcmp, all
eplot
/eof
Edited:
Thank you Carl. I'll be surely follow up the tutorial links you provide.
Dear Gaetano, thanks for taking the time for my problem. The sphere given is exactly what I imagine of. Thank you.
Quick question, let say I need to change the radius, or maybe other parameter of your given sphere, can I do so on the sphere or do I need to create a new sphere starting from the first step?
Dear sir,
How can we do mapped meshing to the quarter part of hemisphere with one hole placed on the surface and one hole at edge of the model.?
or how should we make division for this model to make valid topology for mapped meshing?
I have attached model for understanding purpose.
Kindly help me
Thanking You in advance.
Hello to all
I have a squre block and inside it there is an sphere. I want to mesh
the whole assembly mapped meshing. I tried to devide it into 8
parts. That helped me to mesh the sphere but i cant mesh the squre with
spherical hole with that too. So please you can help me out.
/BATCH
/COM,ANSYS RELEASE Release 16.1 BUILD 16.1 UP20150325 08:21:29
/input,menust,tmp,''
/GRA,POWER
/GST,ON
/PLO,INFO,3
/GRO,CURL,ON
/CPLANE,1
/REPLOT,RESIZE
WPSTYLE,,,,,,,,0
/PREP7
!*
ET,1,SOLID185
!*
/VIEW,1,1,1,1
/ANG,1
/REP,FAST
BLOCK,,10,,10,,10,
!WPSTYLE,,,,,,,,0
KWPAVE, 5
SPH4,10,10,5
VSBV, 1, 2
thanks alot
Dear Ilan,
take a look at the attached file.
It is not the best way of doing the job but it could be anyway useful as an example.
Best,
Gaetano
Dear Gaetano Giunta
I am grateful to explain the reasons for the divisions (partitioning) of the cube, in general
Best regards
In general, your CAD should be organised in a manner that is easy for the mesh generator to use only brick elements. This means that you need a geometry that is an assembly of parallelepipeds or the like (volumes with 6 faces even if not straight as in the case of the sphere). This is not easy and maybe not always possible. You need some experience. In order to get it, I suggest you to start playing with two-dimensional problems (e.g. meshing a circle or a triangle).
Enjoy,
Gaetano
Thanks alot. but Is it possible for you to introduce me a source of examples to gain experiences.
Best regards
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