Tetrakaidecahedral @ Kelvin structure

You mean like this?

Looks a bit random but it appears to be build up from hexagons and squares to me.

yeah... that structure look likes that...its foam structure...do you have any ideal to draw that structure using SolidWork or any kind software???.... im really need that structure..because before this im draw but then assemble it... actually i want in 1 part...

I am sorry to say that I do not have the necessary skills for drawing these 3D but have you tried globalspec solidworks information search? Maybe they have ready to use templates for this.

Also when in globalspec you can contact the various companies that do these drawing programmes, maybe they can help you as well.

Go to globalspec.

Good luck and thanks for coming back.

Thanks... its okay..nevermind... i'll try to find in website u gave to me >> globalsplec..

anyway thanks again...im appreciate it

I would draw a sphere then define planes for each face.

After, cut extrude to form your shape.

This will form a filled solid, repeat the steps to form a hollow structure.

You need to determine the angles of each plane which is simple mathematics of course.

I think the original poster might have meant if there was a set structure within any of the software programs that would build this shape, like you have "materials" in paint shop pro 8. Not sure but academic any way as I still would not know.

I do not know paint shop pro, but one can use VB to program solidworks to perform complex operations.

This link seems to provide the basics for a sheet metal approach in the design.

Hey Giga,

Sorta late last night I missed your link you posted and I then posted same .

They say great minds think alike - I guess ours do too.

Anyway, credit where credits due, and that would be you!

cr3

thanks for both of u C_Rummel3 n Giga...coz both of u give a good suggestion to start from origami part...

yeah..to make it easier is begin with sphere shape...then shell it...i'll try my best... hopefully i can define the planes for each face with the right angle ..thanks coz give me the suggestion

Perhaps the simple way is to make parts (square and pentagon) from the PDF in the link I posted, and then build an assembly.

For your information dear, i already assemble that origami.... i also ever assemble each planes for square and pentagon and become a tetrakaidecahedral..but the problem is..i cant make simulation to apply some load..because its not 1 part...that is why is possible i want to make it start from sphere then cut it and shell it

The object can actually be drawn as an array of 2D components assembled to a 3D appearance by creating a four sided shell of that surface.

To try and extrude something like that.....not me!

here is the flat pattern. It is a pdf format. http://zapatopi.net/kelvin/tetrakaidecahedra.pdf

So think about drawing in 2D, folding as would paper and voilá!

Hope this helps.

cr3

Thanks ..C_Rummel3...i ever try use this pdf then make it by paper..but its too difficult to make it using software...actually..if i cant i want to make it from sphere then cut it to kelvin then shell it... but until now..my drawing still not success..anyways thanks

Here is my attempt to build it from paper. Has now officially gone down as the most difficult thing to build from paper for mere mortals and I shall never do another one.

Anybody wants some ready printed sheets with the outline, anybody?

Im appreciate it..that u all really help me..thank a lots . yeah right now..i will try to measure the angles for each plane again....and try to build it

Dear all...this i attach the example i already make it..but its by assemble... each plane i assemble... this part cant make simulation

I buit the same assembly, then saved it as a part. Now the assembly entities are surfaces. Two surfaces are hidden to show the interior, wall thickness is 0.01mm.

It is simpler than building from a 3D sketch or doing cut extrudes.

so giga... u suggest me to do assemble 1st???...then turn it to part??...u think this part can do simulation with some load or not?? if u say okay..i will try it again..becoz before this i ever done this also as shown in the pic i've attached... thanks giga

I think it is worth a try, I am not very familiar with Cosmos.

From what you have done already, it is just a ''Save As'' operation.

Have fun!

okay thanks... i also new in Cosmos... anyways thanks...

I don't think you'll get an accurate structure for load calcs. as this is a hollow body. Deformation under load etc will not be accurate.

I opine.

cr3

C_Rummel3, this one i make for foam structure..then after this i will try simulate when we applied the mechanical response..

hi.. i m making the same model in ABAQUS..but the problem is coming that the edges are not getting connected when we go zooming on the edge....Two lines are coming of the two connecting surfaces as we go zooming in and in....I have applied edge to edge constraints but afterwards it refuses to create contraint ...saying that Previous position constraint is not allowing...So Plz help regarding this..... Plz reply Aniruddh

Draw the solid part you need without the structure in it. Then draw one if the sphere in solid as different part. Look up molding die in help and subtract the sphere from the first part. Pattern the subtracted feature with correct offset to make thin wall. You'll need to subtract more to get the correct staggered pattern.

Pineapple

yeah pineapple ur suggestion is good..but my porblem is ..i dont know how to cut it to kelvin structure from solid part especially from sphere ..do you know how to do it??

By starting with a sphere in a cube. Cut only those surfaces which are at 180° to one another. Since you know the angles you can calculate the lengths and thus the area.

Maybe?

cr3

ok thanks C_Rummel.. maybe i should try with clay..the prototype design...

Since you have modeled with surfaces, you can convert the enclosed area to solid. Or cut the sphere/cube with the surfaces.

Pineapple

Dear pineapple,,

its this object in 1 part??..how about the angle of the each plane u assembled?

It is one part. Did not use angle between planes because it'll not be accurate. I constrain a 3D wire frame sketch with proper 90 and 120 degree then use the lines to create reference planes for extrusion. I use extrude to vertex so I don't need to know extrusion length.

Simple part but not easy to draw.

Pineapple

Hey,

I've had the need to draw tetrakaidecahedrons for months now, and I've streamlined my process quite significantly. I modelled mine in Unigraphics / NX, but I expect it's similar enough to draw in other CAD packages. I will attempt to explain how to draw one here:

1) Create a cube that is half the width/height/length of the tetrakaidecahedron you want to make.

2) Draw a line from one corner of the cube to it's opposite.

3) Create a datum plane that is normal to that line at it's midpoint.

4) Trim the cube to that datum plane.

5) You now have one eighth of a tetrakaidecahedron! Mirror that shape until you have a tetrakaidecahedron and unite them all together. You will have formed a mathematically perfect model that you can parameterise.

I hope this helps!

hye...

Thanks for ur suggestion..... actually i already success to make that model..i start it from cubic then i cut n lastly shell it.... right now i try to model it using cosmoswork..... ..any ways...thanks again... i want ask u something.... Do u ever use SolidWork software/??

Ah, I thought I read all the comments, looks like I missed a few! No, sorry, I don't use SolidWorks!

Dear Zunaida,

Can you please share your experience , how to draw the tetrakaidecahedral structure (preferably in Pro-E or Ansys). I am going through the same phase in which you was about one year before. I want to do some simulation on aluminum foam structures.

Saeed

Dear Saeed...

actually you can draw that structure start from cubicle... from that you can cut it.. into tetrakaidecahedral.... before this..im also have same problem with you..that i dont know how to make it.. but now.. Im expert to draw it ..but by using Solidwork.... hopefully you can draw it..but make sure you know the angle to cut it....good luck...if you have problem please inform me...

Dear Zunaida,

Thanks for your reply, yesterday I was success by following the procedure mentioned in comments #34 by Guest. I need your help in further process.

I am confused in selecting the Kelvin cell model for aluminum foam structure with planer faces, curvature faces or with variable thickness for good results. So far I made it with planer faces having equal thickness.

I will be thankfull if you share your research or simulation results, so that I can compare them with mine.

If you have some tips or suggetion regarding modelling and simulation of aluminum foam, kindly share your experience.

Please read the following journal article for modelling large-strain response of tetrakaidecahedral foam

Finite element analysis of closed-cell aluminium foam under quasi-static loading
Materials & Design, Volume 31, Issue 2, February 2010, Pages 712-722
S.K. Nammi, P. Myler, G. Edwards

hi friend, As i have already mentioned that I have been facing problem in Modeling of Tetrakaidecahedron in ABAQUS. The problem is that......Consider Thickness Of HexaGon plate... On touching hexagon to hexagon (since hexagon will make some angle with other hexagon), the outer boundary of both is not getting stick to each other... I have given Edge to Edge Contraint on the square face to make sure that all the hexagon on its edge touches the square edge perfectly but on giving the same constraint on hexagonal faces, the messsage comes that IT IS CONFLICTING THE PREVIOUS POSITION CONSTRAINT... So plz tell..which procedure should I follow to make the model??

@Zunaida...Thanks.

@ aniruddh,

I use ARRAY command in PRO-E, I hope this command will be available in ABAQUS.

Regards

Hi Saeed... Can u share ur email ID?? May be this can be useful to u also....

saeedbadshah@hotmail.com

hi saeed... will u plz let me know that u have started to make the closed cell model...with 3D part...or 2D planar part??

hi friend.. can u plz tell how to calculate young's modulus and shear modulus etc. for closed cell foam?? plz reply.. If there is any paper regarding that then plz tell that also

Read this article first before you attempt to model tetrakaidecahedral foam. Also read this book: cellular solids by L.J.gibson and M.F.Ashby for formulations related to modulus, shear stress etc.,

Finite element analysis of closed-cell aluminium foam under quasi-static loading
Materials & Design, Volume 31, Issue 2, February 2010, Pages 712-722
S.K. Nammi, P. Myler, G. Edwards

ABSTRACT

Closed-cell aluminium foam was represented with a new type of repeating unit-cell (RUC) constructed from the tetrakaidecahedra structure. After that the thin shell geometrical parameters and material properties of aluminium foam were assigned to this unit-cell. Finite element studies were then conducted to evaluate the stiffness and mechanical response of this model under large strain. Our results are compared to cruciform-pyramidal and cubic-spherical unit-cell foam models that describe the load and global deformation response in-terms of unit-cell structure. We demonstrate that the plateau phase stress–strain characteristics of our model are more representative of real aluminium foam. It was also found that the crushing resistance and energy absorption capability of tetrakaidecahedral foam was higher than the cruciform-pyramidal and cubic-spherical foam models.

Dear friend... as u have suggested me to read this paper, I have gone through it. One thing to ask about making closed cell model in ABAQUS...that...are u successful in making the model perfectly? as i have tried very hard but didn't get success.. ur reply is important..plz do reply

Depends on what you mean perfectly! An ideal model based on tetrakaidecahedra foam or a random cell structure? If you are thinking to produce a model for random cell foam then the answer is of course No. However, fairly recently researchers from IFAM in germany are working on models based on image processing techniques. What it means? well, Like an X-ray they scan the internal geometry of the foam and the computer automatically generates FE model of the foam.

As far as tetrakaidecahedra foam is concerned, researchers are able to to develop analytical expression for stiffness and energy absorption features. Some of the models are not in open domain as these works are un published.

Best Regards

actually i mean to Ideal Tetrakaidecahedral model.....

Yes, as far as I can remember there are at least three works available on ideal tetrakaidecahedral foam

1. PhD work of McKown, Simon Thomas, theis titled: The progressive collapse of novel aluminium foam structures, Liverpool University,2004

2. From N.J.Mills, Look for the paper titled: Finite element micromechanics model of impact compression of closed-cell polymer foams, I.J.Solids and Structures.

3. journal paper of S.K.Nammi

can i have ur email ID?? if u r willing to give then plz......

Dear friend...

Actually i already make tetrakaidecahedral cell... but i have new problem... it can work using Cosmoswork...but i dont know...what data i should put in if i want to know the young modulus of the of the cell... its the young modulus of PE foam or PE virgin?... the other data i can put is poison ratio and relative density... if this cant work with Cosmoswork...then i should use Ansys.. a new software for me... it really make me worry....please give advice

There is formulation for relative modulus of tetrakaidecahedral foam based on Simone and Gibson formulation. Look the papers titled:

Effects of solid distribution on the stiffness and strength of metallic foams, Acta Mater 46 (6) (1998), pp. 2139–2150

If you know the virgin metal Young's modulus you could find the Modulus of foam. The poisson's effect for form is always considered as zero.

If you are doing a static analysis then ANSYS is sufficient.

Dear friend, Thank for your advise and suggestion... in last message you said that " If you know the virgin metal Young's modulus you could find the Modulus of foam" so that is mean I can measure the modulus of foam even i put in the modulus of virgin materials.... dear friend thanks again... here i would like to know... do you have any suggestion what analytical model should i use... besides Voronoi

There is an analytical model for relative modulus of tetrakaidecahedral foam. It is printed in Paper titled:

The high strain compression of closed-cell polymer foams;Journal of the Mechanics and Physics of Solids;N.J.Mills and H.X.Zhu

Dear Guest,

Thank You so much... ..

I will start use and learn the Ansys... this is my 1st time.. and last solution for my research.. hopefully it will successfull..thanks again

Hello Zunaida,

Could you suggest some idea to create a tetrakaidecahedron model or kelvin unit cell using Autodesk inventor? If i get an over all idea to design the kelvin unit cell model then i can do on my own. I am looking forward for your reply. Thanks in advance.

Kind Regards,

Karthikkumar