Dear Dr. Michael, I hope this message finds you well. I wanted to express my gratitude for the invaluable resources you have provided. Your expertise has been incredibly helpful in my current research on numerical and experimental analysis of thermal conductivity on silica fibrous materials with random voids. I understand the importance of software in this analysis, and I would greatly appreciate it if you could let me know when your software becomes available. I am particularly interested in considering air-trapped bubbles within the cylinder-shaped model and running a heat transfer analysis. Would appreciate it if you let us know how to reach out to you. Thank you for your time and consideration.
Hello, thanks for your kind comments. I am glad these videos are helping you with your work. Your research does sound interesting. I have never worked on air-trapped bubbles so it would be interesting to hear more about the work. I would usually be contacted via the email in the About page of this channel. If you have not already done so, you can also subscribe to my CM Videos Newsletter here: cmvig.cmvideos.org, and you can contact me via the welcome email you receive. If you reach out to me, we can discuss this issue further.
Dear Dr. Michael, First, I want to express my heartfelt gratitude for the quick response. Your dedication to helping others in their research is truly admirable. I appreciate your willingness to provide your email address and I want to let you know that I will be reaching out to you shortly. Thank you again for your time and expertise.
Thank you so much sir for this valuable video on RVE modelling. I request you to please make a video on how we can perform modelling and calculation of hardness of RVE model of particulate metal matrix composite.
Hello, thanks for this question. I have not modelled hardness before but I will note this query and see if this is something I can do. It does sound interesting and I would imaging RVE-based modelling with nano-indentation will be the right approach to use.
Doc, your videos are really enlighting me and helping a lot thanks for them didactic nature! I have a similar problem related to FEM composite materials in Abaqus. How can we have a private exchange?
Hello, thanks for your comment. I am happy to hear you found the videos helpful. I have my email address on the About me page of this channel, so you can contact me there. Alternatively, join my CM Videos Insider group via this link: cmvig.cmvideos.org and from the welcome email, be able to reach out to me directly.
Dear Dr. Okereke Thank you for your useful instructions on composite modeling material. I have 2 questions about modeling complex structures like the human left ventricle in particular. I am incredibly grateful for the invaluable advice you will provide. 1- Is it possible to explain how to model the geometry of the fibers in the ventricle wall? The shape of the heart is obtained by MRI. The fibers wrap from the bottom of the ventricle and go up. The heart wall is a layered structure and in each layer, the fibers' orientations are not the same. They differ from -70 degrees in the outer layer to +70 degrees in the inner layer. 2- I have an Excel file that has the direction of fibers and the number of the elements to be corresponded. How can I assign fiber directions to the corresponding elements? For example, the element E1 has the fiber orientation (x1,y1,z1). The model has more than 6000 elements and it's not possible to draw the fiber one by one. I can provide you more details about my questions if you are interested. Best regards
Hello, thanks for your comment and I am happy to note you find these videos helpful. It does sound like a challenging job what you are trying to do. I do not have any experience modelling ventricle walls or heart modelling so unable to help with the question. More generally, I think you would be better of creating the fibres (6000 of them) using some sort of automated scheme maybe within a python script. I think if you can create one to learn the process in ABAQUS, then convert the implementation into a Python script by assessing the *.jnl file resulting from the simulation, that could be a good place to start. I also think such complex fibres within the ventricle wall might be better developed inside a CAD tool like SolidWorks which when you are happy with it, then import into say ABAQUS to undertake the stress analysis. I have a video on the channel about asigning orientations to heterogeneous media, please check that out here: ruclips.net/video/W34LrXDMhOA/видео.htmlsi=5lHhr7c_SDgSMMwx
Sorry, I am not able to help. It sounds like this should be done using a script again but unfortunately, I am not so knowledgeable in this specific challenge.
Thank you very much for the highly informative video, it would be of great help if a user-defined interfacial transition zone between particles and matrix is added to the modelling package
Thank you for this video, in the case of using the MoriTanaka model for this RVE, what are the formulas to use to calculate the effective properties E and G?
Hello, there is a formula for the Mori-Tanaka model and it can be used for this. I suggest you dig up a journal paper or book where this formula is stated and try it out. It can help you determine the effective properties as well.
Dear Dr. Michael, I would like to extend my warmest greeting and appreciation to you. I am very interested in your posts on RUclips. It means a lot for future engineers and researchers as well. So, Keep your momentum. May I ask if you could elaborate more about how can I access the MontGen3D software for my research work on syntactic foam with different volume fractions of microballoon? Thank you again for your supporting videos!
Hello, thanks for your kind comment. I have a developmental version of the code (which I have re-written into GenParticles3D version 1). It should be able to create voided systems which will capture your objective of a syntactic foam, if I am correct. I am working on final editing of the code to get it ready for public release. You can email me and we can discuss more. But if not, watch this space until I get it ready for public use.
Thank you very much for this fantastic video. Could you briefly explain why you would apply the displacement load to a reference point tied to the surface and not directly to the surface? I really appreciate your work. ❤ Hephaistion
Hello Hephaistion, thanks for loving the work. I appreciate that. Its such a good question. Over the years of modelling, especially these RVE models where you want to homogenize across the bulk of the volume over all elements to extract stress-strain values, I had to deal with a lot of variables. For example, if I want to get S11 (stress in the x-axis) for a model that has 10000 elements, then, I will have to record in history variables over the timesteps of the simulation all 10000 elements for S11. I will then do same for strain (E11). You will find out that you will soon run out of memory with ABAQUS not often able to store in history variables more that 10,000 data points. The solution to this is to use that Reference Point, where you are only tracking two variables RF1 and U1 and so will never run out of memory. This is the main benefit. I also like it because it is a bit like attaching the specimen to a load cell which gives you a force measure whiles a cross-head displacmement or extensometer gives you the displacement, U1. This is consistent with experiments. The down side is that you will then have to post-process your force and displacement measures into a stress- and strain measure but this is again similar to what you do with real experiment. This is precisely why I do this and I hope this makes sense to you.
Hello, the code is not yet released for public use. I am working with a beta version but when this is ready you will know. I suggest you subscribe to my email list where I will share the information of the official release to interested persons. Here is the link to use: cmvig.cmvideos.org
Sir could you please upload video on compression testing of carbon epoxy resin cylindrical rod of volume fraction 60% where we have to do python scripting for adding lakhs of fiber in Matrix
This seems and extensive video to make and I do not usually make this type of video that appears to be a research project. Good luck with the work. I simply make videos on sub-sets of a bigger project to demonstrate a single point.
Thank you, Dr. Michael Okereke, sо much!!! You are the only one on the Internet who talks about RVE volumetric computer modeling.
Thanks Valera for your kind comments. I appreciate that and happy new year!
I wish you happiness and good health!!!@@MichaelOkereke
Dear Dr. Michael,
I hope this message finds you well. I wanted to express my gratitude for the invaluable resources you have provided. Your expertise has been incredibly helpful in my current research on numerical and experimental analysis of thermal conductivity on silica fibrous materials with random voids.
I understand the importance of software in this analysis, and I would greatly appreciate it if you could let me know when your software becomes available. I am particularly interested in considering air-trapped bubbles within the cylinder-shaped model and running a heat transfer analysis.
Would appreciate it if you let us know how to reach out to you.
Thank you for your time and consideration.
Hello, thanks for your kind comments. I am glad these videos are helping you with your work.
Your research does sound interesting. I have never worked on air-trapped bubbles so it would be interesting to hear more about the work.
I would usually be contacted via the email in the About page of this channel. If you have not already done so, you can also subscribe to my CM Videos Newsletter here: cmvig.cmvideos.org, and you can contact me via the welcome email you receive.
If you reach out to me, we can discuss this issue further.
Dear Dr. Michael,
First, I want to express my heartfelt gratitude for the quick response. Your dedication to helping others in their research is truly admirable.
I appreciate your willingness to provide your email address and I want to let you know that I will be reaching out to you shortly. Thank you again for your time and expertise.
Thank you so much sir for this valuable video on RVE modelling. I request you to please make a video on how we can perform modelling and calculation of hardness of RVE model of particulate metal matrix composite.
Hello, thanks for this question. I have not modelled hardness before but I will note this query and see if this is something I can do. It does sound interesting and I would imaging RVE-based modelling with nano-indentation will be the right approach to use.
Thank you sir for the consideration
Doc, your videos are really enlighting me and helping a lot thanks for them didactic nature! I have a similar problem related to FEM composite materials in Abaqus. How can we have a private exchange?
Hello, thanks for your comment. I am happy to hear you found the videos helpful. I have my email address on the About me page of this channel, so you can contact me there. Alternatively, join my CM Videos Insider group via this link: cmvig.cmvideos.org and from the welcome email, be able to reach out to me directly.
Dear Dr. Okereke
Thank you for your useful instructions on composite modeling material. I have 2 questions about modeling complex structures like the human left ventricle in particular. I am incredibly grateful for the invaluable advice you will provide.
1- Is it possible to explain how to model the geometry of the fibers in the ventricle wall? The shape of the heart is obtained by MRI. The fibers wrap from the bottom of the ventricle and go up. The heart wall is a layered structure and in each layer, the fibers' orientations are not the same. They differ from -70 degrees in the outer layer to +70 degrees in the inner layer.
2- I have an Excel file that has the direction of fibers and the number of the elements to be corresponded. How can I assign fiber directions to the corresponding elements? For example, the element E1 has the fiber orientation (x1,y1,z1). The model has more than 6000 elements and it's not possible to draw the fiber one by one.
I can provide you more details about my questions if you are interested.
Best regards
Hello, thanks for your comment and I am happy to note you find these videos helpful.
It does sound like a challenging job what you are trying to do. I do not have any experience modelling ventricle walls or heart modelling so unable to help with the question.
More generally, I think you would be better of creating the fibres (6000 of them) using some sort of automated scheme maybe within a python script. I think if you can create one to learn the process in ABAQUS, then convert the implementation into a Python script by assessing the *.jnl file resulting from the simulation, that could be a good place to start.
I also think such complex fibres within the ventricle wall might be better developed inside a CAD tool like SolidWorks which when you are happy with it, then import into say ABAQUS to undertake the stress analysis.
I have a video on the channel about asigning orientations to heterogeneous media, please check that out here: ruclips.net/video/W34LrXDMhOA/видео.htmlsi=5lHhr7c_SDgSMMwx
@@MichaelOkereke Thank you for your response. Is it possible for you to help me with my second question, please?
Sorry, I am not able to help. It sounds like this should be done using a script again but unfortunately, I am not so knowledgeable in this specific challenge.
Thank you very much for the highly informative video, it would be of great help if a user-defined interfacial transition zone between particles and matrix is added to the modelling package
Great suggestion! I will consider this in future.
Thank you for this video, in the case of using the MoriTanaka model for this RVE, what are the formulas to use to calculate the effective properties E and G?
Hello, there is a formula for the Mori-Tanaka model and it can be used for this. I suggest you dig up a journal paper or book where this formula is stated and try it out. It can help you determine the effective properties as well.
Dear Dr. Michael,
I would like to extend my warmest greeting and appreciation to you. I am very interested in your posts on RUclips. It means a lot for future engineers and researchers as well. So, Keep your momentum. May I ask if you could elaborate more about how can I access the MontGen3D software for my research work on syntactic foam with different volume fractions of microballoon?
Thank you again for your supporting videos!
Hello, thanks for your kind comment. I have a developmental version of the code (which I have re-written into GenParticles3D version 1). It should be able to create voided systems which will capture your objective of a syntactic foam, if I am correct. I am working on final editing of the code to get it ready for public release. You can email me and we can discuss more. But if not, watch this space until I get it ready for public use.
Thank you very much for this fantastic video.
Could you briefly explain why you would apply the displacement load to a reference point tied to the surface and not directly to the surface?
I really appreciate your work.
❤
Hephaistion
Hello Hephaistion, thanks for loving the work. I appreciate that.
Its such a good question. Over the years of modelling, especially these RVE models where you want to homogenize across the bulk of the volume over all elements to extract stress-strain values, I had to deal with a lot of variables. For example, if I want to get S11 (stress in the x-axis) for a model that has 10000 elements, then, I will have to record in history variables over the timesteps of the simulation all 10000 elements for S11. I will then do same for strain (E11). You will find out that you will soon run out of memory with ABAQUS not often able to store in history variables more that 10,000 data points.
The solution to this is to use that Reference Point, where you are only tracking two variables RF1 and U1 and so will never run out of memory. This is the main benefit. I also like it because it is a bit like attaching the specimen to a load cell which gives you a force measure whiles a cross-head displacmement or extensometer gives you the displacement, U1. This is consistent with experiments.
The down side is that you will then have to post-process your force and displacement measures into a stress- and strain measure but this is again similar to what you do with real experiment.
This is precisely why I do this and I hope this makes sense to you.
@@MichaelOkereke that is a very smart solution and it makes sense to me too. Thanks for the reply. :-)
Can i use matlab code?
and how do i access this code?
thank you!!
Hello, the code is not yet released for public use. I am working with a beta version but when this is ready you will know. I suggest you subscribe to my email list where I will share the information of the official release to interested persons. Here is the link to use: cmvig.cmvideos.org
Sir could you please upload video on compression testing of carbon epoxy resin cylindrical rod of volume fraction 60% where we have to do python scripting for adding lakhs of fiber in Matrix
This seems and extensive video to make and I do not usually make this type of video that appears to be a research project. Good luck with the work. I simply make videos on sub-sets of a bigger project to demonstrate a single point.