I like the man, thank you for sharing your knowledge
@MichaelOkereke
2 жыл бұрын
My pleasure, thanks @Mehran Faraji!
@madancmaurya328
2 жыл бұрын
On which scale analysis is based on? And if number of fibre is more then how you will model e g CNT tubes.
@MichaelOkereke
2 жыл бұрын
Hello @Madan C Maurya, thanks for the query. I did not make that clear... the fibres are at micron scale i.e. 1e-6 m. Where more fibres are considered, then it might still be admissible to use this approach but it begins to tricky as the mesh size rises significantly. This is why people will often switch to mesoscale modelling of the laminae instead of individual fibres as shown here. For CNT tubes, I actually have a video where I used similar RVE modelling approach here. Maybe, you can see if this will help you, here is the link to the video: kzitem.info/news/bejne/k6CCv2VvapZ3oGk
@lejieliu7774
2 жыл бұрын
Hi sir, very interesting video! I wonder why you introduced x, y, and z direction roller BCs instead of periodic BCs in this case? Also how to apply the periodic BCs in 3D domain? I only see your video applying periodic BCs in 2D.
@MichaelOkereke
2 жыл бұрын
Hello @Lejie, thanks for the comment. The x-, y- and z-direction rollers is to ensure that appropriate dirichlet BCs that enforced pure uniaxial deformation is imposed on the 3D RVE. I have not used PBC in 3D as this code is not available yet. There is no automatic way of doing so inbuilt within ABAQUS except one uses a bespoke software developed for this.
@hanibalsmith9460
9 ай бұрын
Thanks for the nice tutorial. Once the multilayered model geometry is completed, how do you select the RVE? As the different layers have different angles, it is quite confusing to visualize and select the RVE for further analysis. Could you please some suggestions
@MichaelOkereke
9 ай бұрын
Hello, I am not sure about the question but what I would do is to simply draw a block selecting all at the assembly stage. You would have to bring all parts into the assembly to select all. If you are trying to visualize the model instances for all parts, I would normally whilst in the Assembly module select something like viewing it in the Load view or surfaces view so that you can see what is happening inside. Alternatively, if everything is in the assembly module, then you can suppress say the matrix part which will reveal what is inside. I am trying my best to explain based on my understanding of the question. Please explain the question further if I am getting it completely wrong.
@hanibalsmith9460
9 ай бұрын
@@MichaelOkereke Once we model the full geometry of the multilayer composite with each layer denoting different angles of fibres, say 0-45-135-0, once I stake the fibres like this, how can I select a portion that represents the repeating units. In your periodic boundary conditions and representative volume element tutorials, you mentioned taking the repeating units. So, for this complex multilayered fibres, how can we find a repeating cell
@MichaelOkereke
9 ай бұрын
Okay, I understand the question now. YOu see for the laminated system with stacking sequence of say 0-45-135-0, unfortunately, you would have to represent all of them within an RVE for such RVE to be deemed admissible for carrying out a simulation. The repeating unit will include all of them. This is where the idea of Repeating units fails especially since the smallest unit of the RVE is the same as the structural/macroscale unit. This is not the case for UD composites which at fibre-level represents a repeating unit, especially if the UD has ordered fibre arrangement. If not ordered, again, you would have to use a larger RVE to create effective simulation of properties.
@hanibalsmith9460
8 ай бұрын
@@MichaelOkereke Yes, exactly. Now, the RVE is quite large, and another problem is that because of angular alignment, nodes on the opposite faces are not parallel. It seems like the general way of applying PBC in your earlier tutorial is not applicable to this case. How can we approach this situation, Is there any simplification in BC's or any thoughts about this?
@jorghoyland
Жыл бұрын
Great video and you clearly know your stuff. But can you drop the music?
@MichaelOkereke
Жыл бұрын
Hello @Dr Carbon, thanks for the comment. Good suggestion. My recent videos do not have the music as I have had a few comments about it. Thanks for taking time to comment.
@纳米-l1t
4 ай бұрын
How does abaqus simulate the interlayer slip behavior of CFRP prepreg laminates at 75°C?
@MichaelOkereke
4 ай бұрын
You have to use interphase model probably with a cohesive zone element.
@hanibalsmith9460
8 ай бұрын
@MichaelOkereke for a multilayer composite, I found a mirror symmetry, in that case is it possible to make RVE from that
@MichaelOkereke
8 ай бұрын
I think you can make an RVE from the Mirror symmetry. This is okay. Try it out.
@sirajudheench8819
Жыл бұрын
instead of this method, i modelled composite plate as a orthotropic plate with E1,E2,E2,G12,g13,v12.v13 etc.......... for structural applications. is that fine?
@MichaelOkereke
Жыл бұрын
Hello @Sirajudheen, you are right about the method involving those constants. This is treating the composite as a homogenized lamina. I used a micromechanical approach in this video, in which case thre waas a distinct representation of fibres and matrix in the RVE. This could be something for me to consider: the laminate composite approach.
@sirajudheench8819
Жыл бұрын
howto see stress values S11 in each layers? i have a composite plate with 8 layers. pls help me.
@MichaelOkereke
Жыл бұрын
Hello @Sirajudheen, you just need to switch the stress from von Mises (the default) to S11, that is if you did it with my type of approach. However, if you are using the laminate composite approach where you used homoogenized lamina properties, then you will have to use the local material coordinate system of the ply to extract the relevant S11 values. The later is not something I did in this video as this is not relevant here.
@aminaakkal6520
2 жыл бұрын
Please docter i have question about this modelisation for exemple bouligand when i meshe it manuel and i do stress simulation i have problème of interaction between fiber and matrix please can you modilise a bouligand structure and interaction between fibre and matrix and real mesh
@MichaelOkereke
2 жыл бұрын
Hello @Amina, thanks for the query. I will bear that in mind. Good luck with the work.
@aminaakkal6520
2 жыл бұрын
@@MichaelOkereke thanks you r great man if you want you encadrer me in my phd doctorat
@aminaakkal6520
2 жыл бұрын
@@MichaelOkereke can you give me ur WhatsApp number
@tvify
2 жыл бұрын
Hi sir, Thank you for this video. Can you do a tutorial for a composite with randomly oriented fibres (ex. natural fibre reinforced concrete)? Thanks
@MichaelOkereke
2 жыл бұрын
Great suggestion @MechStuff! I will look into it in future.
@tvify
2 жыл бұрын
@@MichaelOkereke Thank you so much dear sir. Eagerly waiting
@houdafoulah1488
2 жыл бұрын
Hi sir, Thank you for this video. Can you do a tutorial for a composite with randomly oriented fibres (fiberglass reinforced polyester matrix composite)? for tensile and bending test,I really need it, and how can I insert the percentage of fibers on abaqus.Thanks
@MichaelOkereke
2 жыл бұрын
Hello @Houda Foulah, thanks for the comment. Are you interested in a short fibre composite with the inclusions randomly oriented? If so, then I do not have a video on this yet but this could be inspiration for a future video. I am not sure what you mean by tensile and bending. Do you want such load cases on the micromechanical model of the reinforced composite?
@houdafoulah1488
2 жыл бұрын
Thank you sir 🙏🙏
@aminaakkal6520
Жыл бұрын
Hey how you can model à sampl tesile test laminate carbone epoxy cfrp for exemple 200mm L 50 mm w
@MichaelOkereke
Жыл бұрын
Hello @Amina, I have it in mind to make such a video in future. Watch this space!
@aminaakkal6520
Жыл бұрын
@@MichaelOkereke thanks Mr for ur help ☺️
@azazkamal842
2 жыл бұрын
Hi sir. can you do video on Directionally distributed steel fibre reinforced concrete
@MichaelOkereke
2 жыл бұрын
Will try
@azazkamal842
2 жыл бұрын
@@MichaelOkereke sorry sir for the late reply, because I was outside the city and i haven't checked your message
@mehranfaraji8148
2 жыл бұрын
Make it possible to pay for PBCGen2D with PebPal, too. Thank you
@MichaelOkereke
2 жыл бұрын
Hello @Mehran Faraji, the platform I use does not allow for PayPal, I assume that is what you mean. However, you can send me an email directly (by subscribing to my CM Videos Insider Group - see link at description of this video). Then, we can take the discuss forward from there.
@flyk7019
2 жыл бұрын
Hi,Dr Michael. I had been calculated the laminated composite ABD matrix,i want know the relationship between it and stiffness matrix.Do you kwon it? thanks!
@MichaelOkereke
2 жыл бұрын
I do not understand the question. What do you mean by ABD matrix?
@flyk7019
2 жыл бұрын
@@MichaelOkereke you can look this, www.sirris.be/sites/default/files/content/composites-whitepaper-5-laminate-theory.pdf
@MichaelOkereke
2 жыл бұрын
Hello @Fly K, thanks for sharing the link. I now understand that you refer to the [A], [B] and [D] stiffness matrices associated with a laminate undergoing deformation. In terms of the relationship between these and the stiffness matrices, here are some thoughts. 1. You need to distinguish between one-lamina behaviour (i.e. plies oriented in one axis and subjected to deformation) from a laminate behaviour where multiple laminae are stacked up together to form a composite. 2. For a lamina, the critical relationship between stress and strain is defined by the stiffness matrix much like a hookes law where stress, sigma = Modulus, E multiplied by strain, epsilon. The proportionality constant for such a system is the Modulus. For a lamina, this is much more complicated and has multiple terms that relate to behaviour in the different axis of the composite. For such, only the stiffness matrix is what you need to define material behaviour. This is much like the extensional matrix [A] which relates only to strains in 1- and 2-directions and 12-shear plane. 3. For a laminate, the relationship extends beyond just the extensional matrix to also curvature and coupled curvature-extensional terms. This is where the ABD matrix comes in, and it offers a holistic characterization of the behaviour of the laminate accommodating the extensional, curvature and coupled curvature-extension relationships. 4. In terms of relating the ABD matrix to stiffness matrices, I will say this is not a reasonable exercise as they are very different. You can however consider a case where a laminate has say [0]_{10} which means 10 lamina plies all oriented in one direction as the lamina. For such a case, the ABD matrix simplifies to a stiffness matrix. However, such a laminate is not the reason for use of laminate so such simplication is unnecesary. 5. For you to understand it at a rudimentary level, I will say the stiffness matrix is sort of comparable to the extensional matrix, [A] of the laminate but you have to be careful about this as the A-matrix in a laminate does not live independent of the other matrices in a true multiple stacking sequence laminate. Its a long explanation but I hope this makes sense to you.
@flyk7019
2 жыл бұрын
@@MichaelOkereke thanks for your long interpretation, Dr. Michael it helps me a lot.
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