Very interesting video thanks from Algeria.

@MichaelOkereke

2 жыл бұрын

Glad you enjoyed it!

Thanks for your very helpful content. I have a question about PBC Theory's video. Consider the simulation of a tensile test in the case of 2D quadratic RVE. Why do we enforce loading only at the corner node? Can we apply displacement, for instance, U2, to the top edge and fixed bottom (endcaster B.C) edge? Are the results of these two problems inconsistent?

@MichaelOkereke

2 жыл бұрын

Hi @Mohmd Hosein Gk, thanks for your interest in the channel. Here are my thoughts: 1. Enforcing loading only at the corner nodes is required for this type of PBC because you only have those 4 corner nodes to use to apply PBCs. All other boundary nodes have been prescribed with PBC constraints anyway. So, if one wants to impose a tensile loading, then those are the four nodes you can and should use. 2. The tensile test case you suggested in deed can be imposed on the PBC-enabled domain, all you need to do is the base/bottom (two corner nodes) will be imposed with a fixed/roller support, and then the top edge nodes will be imposed with the displacement load. You should test it out for yourself and see what you get. 3. On consistency of results between my type of tensile case and the version you suggested, they will be different. What you described is an experimental setup for a tensile test where one end is securely held in all 3 directions and another end is displaced by a uniaxial load. This will lead to a tensile deformation where the held/fixed end shows no lateral displacement while the middle section shows deformation, leading to an hour-shape deformation profile. This is a mixed deformation type which is not uniquely uniaxial. For the type that I use, it is truly uniaxial all through the domain because of the nature of boundary conditions I selected. I hope the above explains your confusion.

@MichaelOkereke thanks for the detailed tutorial on how to apply the PBC. Instead of displacement, is it possible to use some other conditions in equations. I am working in soil models (geotech), i use pore pressure in initial BC, is that possible to include the pore pressure in equation constraints. Could you please comment/suggest few tips about this?

@MichaelOkereke

9 ай бұрын

Hello @HanibalSmith9460, thanks for your comment. I am certain that you can use other variables other than displacement in the *EQUATIONS of ABAQUS. I demonstrated this with Force as a variable other than displacement in this video: kzread.info/dash/bejne/ap2imLSwk9Oahrw.html With regards to pressure as a load, I am not sure if this is viable. This is because pressure is a Neumann-type boundary condition whilst for the canonical equations that I used in the *EQUATIONS, it should be based on Dirichlet equations which can be assigned to a single node. You will need a surface to apply pressure. I will suggest what you can do is to convert your pressure to its force equivalence and follow the approach I demonstrated in the video link above. Let me know if it works and how you get on as I am interested in what you find out.

Hello and thank you for this amazing video, for 3D RVEs what kind of boundary conditions should we use?

@MichaelOkereke

2 жыл бұрын

+ilda abdollahi - Thanks for your interest in the channel and glad you found the video useful. For 3D RVEs, you can use PBCs as well but a different formulation will be used in that case. I will make videos about this in future. Before that, the Dirichlet and Neumann BCs will still be okay.

@wanglizhe9815

2 жыл бұрын

@@MichaelOkereke Hello, Dr. Okereke, I'm currently analyzing the periodic boundary conditions with 3D RVE model in ANSYS. I studied your work of manually adding the PBC on 2D RVE in ABAQUS, and I would like to extend to the 3D model. However, I have been struggling with the difficulty in formulations of 3D model for quite a few days...... Really need your help....

Hello Sir, it's really an amazing video on the simulation of metal matrix composites. Sir, could you please make a video on surface modification through Friction stir processing by introducing any reinforcing materials such as SiC, Al2O3, graphene, etc.

@MichaelOkereke

2 жыл бұрын

Hello @Ranjan, thanks for your interest. Actually, I have not modelled friction stir processing before so unable to help with this query right now. Good luck with the research.

@ranjanvishwakarma9708

2 жыл бұрын

@@MichaelOkereke Thank you for your reply sir.

Great job Dr. Michael... Could you make some video on modeling hybrid composite with abaqus? Thanks

@MichaelOkereke

3 жыл бұрын

Great suggestion Di Leckma! I will consider making that video. Do you have any specific type of hybrid composite you are looking at? Carbon fibre - glass fibre epoxy composite? Any suggestion will help create the right video for you!

@dileckma7552

3 жыл бұрын

@@MichaelOkereke Unidirectional glass fiber with natural fiber jute or flax. ( tensile mechanical properties ). thank you.

@longyang5598

3 жыл бұрын

@@dileckma7552 I am doing similar project :>

@dileckma7552

3 жыл бұрын

Seriously?

Hello sir, thanks a lot for your video, I have purchased the file and also got satisfactory analysis results, but I need to find out the Poisson's ratio of the model, because your script exports an inp file, so when I import the inp file into abaqus, the file is missing the model and has only mesh, so I can't get the stress-strain diagram and Poisson's ratio by the unusual method, please tell me how can I calculate the Poisson's ratio in this case with only mesh.

@MichaelOkereke

4 ай бұрын

I have some other videos on the channel on how to get poisson ratio so you may like to look at that. I may have to make a video to show this based on PBCs but let me know in the comment if this is something you are interested in.

Hello sir, and thank you for your very informative videos. I just have a quick question here. Is PBCGen2D applicable to non-rectangular RVE, e.g., RVE with a circular cross section?

@MichaelOkereke

5 ай бұрын

No, PBCGen2D works only on regular quadrilateral domains and not circular cross-sections. Out of curiosity, what kind of material are you testing with circular RVEs. I read a paper in the past where they were enforcing PBCs on circular (and even spherical) RVEs and thought it was interesting. It is not just common. Thanks.

@pu7358

5 ай бұрын

@@MichaelOkereke Thank you for your quick response. I'm trying to simulate a fiber tow within a fiber reinforced composite. Could you please share the paper that you read which has a circular/cylindrical RVE? It will be very useful for me.

@MichaelOkereke

5 ай бұрын

Hello, here is the paper where they compared circular RVEs with Square/quadrilateral RVEs. They used a formulation of PBCs which is really interesting. Here is the link to the paper: doi.org/10.1002/nme.7142

@pu7358

5 ай бұрын

@@MichaelOkereke Thank you very much for sharing the paper!

Can we apply PBC directly on the lattice, without using face units on it (unlike in your other video) using this software?

@MichaelOkereke

9 ай бұрын

Yes indeed, I simply used the facesheet to mimic reality. If you want to apply loads directly on the lattice structure, yes in deed. YOU just have to make sure there are matching nodes on opposite parallel faces, as required naturally for PBC systems.

@akashsaini6401

9 ай бұрын

@@MichaelOkereke thank you, just to confirm, is it matching nodes or meshes on opposite sides, because after creating mesh I got matching nodes on the edges but meshes are different.

@MichaelOkereke

9 ай бұрын

Hello @akashsaini6401, it is matching nodes. The kinematical constraint equation that imposes PBC are applied on nodes not elements. The mesh might be different but the nodes on collinear opposite faces/edges must match... if you are going to use this sort of PBC I explained here. If you use the interpolation-function-based PBC, then you do not necessary need them matching. That is a different problem though. Good luck with this.

hello professor,i am a student from China,i want to buy the PBCGen2D software,but i found i can't pay for it😢,can i get it by some way else like PayPal?Thank you very much🎉

@MichaelOkereke

24 күн бұрын

Hello, please send me an email on the email address in the About section of this channel or on sales@cmvideos.org

I wanted to know if this software can be used for lattice structures or not?

@MichaelOkereke

9 ай бұрын

Of course yes, it can be

HELLO SIR HOW ARE YOU? I NEED TO IMPLEMENT PBC IN 2D PLAIN WEAVE (for only yarns without a MATRIX) I WOULD LIKE TO KNOW PBC GEN CAN DO SO?

@MichaelOkereke

2 жыл бұрын

Hello @Fikirini Jr, this can be done but would have to be done using PBC for 3D RVEs. I assume your 2D plain weave is a 3D RVE. I currently do not have any video about imposing 3D RVEs but have a publication about this which you can read here: doi.org/10.1016/j.compstruct.2016.10.114

Dear Sir, I want to ask why there is a stress concentration at the boundaries of RVE in second case like very high stresses are generated of the order of 10^7. Like application of PBC don't let this happen. Thanks for reading my comment.

@MichaelOkereke

Жыл бұрын

Hello @Harsh Sharma, thanks for the query. I am not sure which part of the video you are referring to. Please can you give me the time-stamp to where the stress-concentration is in order of 10^7. I cannot find it. However, you can still have stress-concentration even with a PBC. Stress concentrations are as a result of sudden changes in a cross-seciton so for example, around holes, the cross-section changes suddenly and so a stress concentration is built up there. I hope this makes sense.

@harsh_hybrid_thenx

Жыл бұрын

@@MichaelOkereke I got your point. Actually earlier i seen one result of yours of Plastic strain whose magnitude was of order 10^-1 and I compare that with this result of Smises by mistake and i thought the stress is coming very high. That's why I said stress concentration. Also, Does stress concentration arrives if we not use PBC on RVE at the boundaries as been written (Bian et al. , 2021) . Thanks in advance.

@MichaelOkereke

Жыл бұрын

Please let me have the full article of Bian et al, 2021 so I can check out what you refer to here. I do still maintain you should still have stress concentrations even with a PBC but I am okay to be wrong, but let me have your evidence.

Thank you sir very nice video. How can we get full version of the code?

@MichaelOkereke

3 жыл бұрын

Hello Bharat, I will create the digital product for that and make it available with a Video supporting that later. Please just keep coming back.

PBCGenLite can be used for 3D RVE ?

@MichaelOkereke

Жыл бұрын

No Anis, it's for a 2D RVE only.

Sir, I can't download the code from the website you provide, can I find it somewhere else?

@MichaelOkereke

3 жыл бұрын

Hi Zihao, thanks for your interest in the channel and the code. I am not sure what you are doing wrong but here is the direct link to the digital product. Let me know if it does not work. cmvideos.ck.page/products/pbc-gen-lite-v1pt0 Alternatively, if you join my CM Videos Insiders Group with this link: cmvideos.ck.page/16a99bd0e3 , then you can contact me directly to discuss your specific questions. Let me know how you get on.

Can we apply PBCGenLite to a 3D domain?

@MichaelOkereke

8 ай бұрын

Unfortunately the publicly available PBCGenLite 2D is for a 2D domain. For a 3D domain, you will need a different software which is not available yet.

Dear Sir, It would be great if you can share the Abaqus script for generating the model as you did in the previous video of this series so that the guys who want to validate their own Matlab scripts with the results you have come up with in the latter part of the video. Thanks.

@MichaelOkereke

Жыл бұрын

Hello @Harsh Sharma, thank you for the comment. I did not realize I missed out on adding the python script. I have now updated the description section of the video and you can see a link you will need to visit to download the relevant script and other archives of other downloadable resources from this channel which you may like to download as well. You will first need to sign up to my CM Videos Insider group before you can visit the page: cmvig.cmvideos.org. Let me know if all goes well.

@harsh_hybrid_thenx

Жыл бұрын

@@MichaelOkereke Thanks dear sir, I am actually able to implement the PBC with my own python code using the methodology taught by you in the first video of this series. Thanks a lot.

@MichaelOkereke

Жыл бұрын

@Harsh Sharma, this is fantastic. Well done!

could you please let me know if the free version of PBCGenLite is available for students Thank You

@MichaelOkereke

2 жыл бұрын

Hello @alok dwivedi, I do not have a free version of PBCGenLite for students to use. I can offer you a discount on the code but do send me an email via the CM Videos Insider group when you subscribe - you get a welcome email and weekly newsletter from me. Here is the link: cmvig.cmvideos.org

@alokdwivedi1949

2 жыл бұрын

@@MichaelOkereke I have subscribed.. Now what I have to do to get code

@MichaelOkereke

2 жыл бұрын

Hello @alok dwevedi, I will email you to offer you a discount.

Sir, can you please make a video for 3D RVE??

@MichaelOkereke

3 жыл бұрын

Hello Subrat, yes about 3D RVE, it is definitely not that simple especially when you are looking at heterogeneous media. This is because meshing on a surface to enforce periodic mesh on parallel faces/surfaces is not always going to be easy. The nature of meshing algorithms is quite random, so it will be difficult to get positions that match on parallel faces for the method I have introduced to be applicable. This is where the method of non-periodic meshes will come in handy. I hope in future to make a series of videos about periodic boundary conditions for non-periodic meshes. After that, then the culmination of these efforts will be to apply these for 3D RVEs. I suggest we have to wait for it, but thanks for the suggestions

@subratkumarmaharana213

3 жыл бұрын

@@MichaelOkereke Thanks a lot sir