"Dear Dr. Yu,I could run VAMUCH for two RVEs with size of 20×20×

  1. Mehdi Shahzamanian

    “Dear Dr. Yu,

    I could run VAMUCH for two RVEs with size of 20×20×20 um (8K) and 50×50×50 um (125K), including 8000 and 125000 elements via ANSYS interface to obtain the effective elastic properties. Results for 8K are very good, but results for 125K are very arbitrary. I have tested several times but I have not got any good results.I thank you if you advise me.

    With Kind Regards, Mehdi

  2. Hamsasew Sertse

    Dear Mehdi,

    What type of RVE or unit cell ( 2D/3D unit cell or random ) did you use for 50×50×50 um? If you can you may send your input for me so that I may run it here.

  3. Mehdi Shahzamanian

    Dear Hamsasew,

    Thanks, attached is the file. As you can see this RVE is including 17 phases. The maximum value for Young’s modulus is 117.6, but the effective Young’s modulus obtained by vamuch is 260. So it is wrong. If I enter the value of 117.6 for all young’s modulus, it means that RVE is homogeneous and vamuch gives correct effective young’s modulus (Eeff=117.6). I am thinking that I am not considering some factors. I thank if you look at the file and let me know what is wrong with it.

    With Kind Regards, Mehdi

  4. Hamsasew Sertse

    I checked the input file. There is not error with input file. The predictions of VMAUCH for E11 is 24.97 as per specified unit.  I noticed that the RVE is not periodic, please make sure you take larger RVE for better approximating the predictions of the effective properties. Moreover, the prediction of VAMUCH is obtained as a 6x6 stiffness and compliance matrix. Please make sure you get the E11 correctly. Attached is the prediction of VAMUCH.

    Please let me know if you have any questions.



  5. Mehdi Shahzamanian

    Thanks so much, 24.97 as per specified unit is a very reasonable value for Eeff. 

    I am wondering that why I didn't get this value. 

    Please let me check the procedure of running vamuch with you. I should say that:

    1) first I imported the *lgw into ANSYS

    2) I selected the icon of "active MPC" from Solution/Micro Analysis/ Define MPC

    3) Solution /Micro Analysis/ Analysis Type/, I selected the effective properties Analysis

    4)  Solution /Micro Analysis/Solve

    Please let me know if I am right or not. 

    Also, I should mention that my original RVE size is 100x100x100 um including 1000000 element, but I was not able to run it due to computer memory limitation. Kindly let me know if you are able to run them for me, I need to get the results for only 5 files. If yes, please give me your dropbox address.

    With Kind Regards,


  6. Hamsasew Sertse

    Dear Medi,

    I just modified your steps a little bit as I put it as follows.

    1) Imported the *lgw into ANSYS

    2) Preprocessor/UnitCell/Custom Unit Cell/Apply Boundary conditions

    then you put in the box  x=50, y=50 ,z=50 since your RVE is of size of 50x50x50 un.

    3)  Solution/Micro Analysis/ Analysis type/Effective properties Analysis/Elastic Analysis

    4) Solution/Micro Analysis/Solve


    Please send the file via dropbox at

    Please let me know if you have any questions.



  7. Mehdi Shahzamanian

    Thank you, I got it, I didn't apply those boundary conditions because of the error saying that the used version of ANSYS does not support these boundary conditions.

    I am wondering that it might be the reason of having non-periodicity in my RVE. Please let me know if I am right, otherwise please let me know how you understood that the RVE is not periodic.

    By the way, I sent you the files via dropbox at Your help is much appreciated. 

    With Kind Reagrds,



  8. Hamsasew Sertse

    Dear Medi,

    I verified that all your input files are okay. Attached are the predictions for the two cases only. As you know your files are huge and they require the larger computer memory. You may plan to go for SwiftComp the newest version of VAMUCH. SwiftComp is a general-purpose multiscale constitutive modeling code for composites which provides unified modeling for 1D (beams), 2D (plates/shells), or 3D composite structures. It has larger capability and it  is computational efficient code.


    Please let me know if you have any questions.


  9. Mehdi Shahzamanian

    Dear Ham,

    Thanks for your help. I already tried to run vamuch through SwiftComp but the system seems to be not powerful yet as Dr. Yu already informed me. However, I am trying to run through my local computer.

    I thank you for running those two files.  But, I wish you could run only 0.4-0.8 file. This file is the most important file among the files that I sent. However, if it is possible please run it for me, if it is not I thank you again for your help.

    With Kind Regards,


  10. Wenbin Yu

    Mehdi, you lose the benefit of learning if Ham runs the files for you. 

  11. Mehdi Shahzamanian

    Dear Dr.Yu,

    Thanks so much, actually, the files that i gave Ham, is inlcluding 1 million element and my computer does not have the capability to run it. Howevere, if he cannot run it for me, it is OK with me.

    With Kind Regards,


  12. Wenbin Yu

    The computer info you send over indeed looks not powerful, particularly only 2 GB memory. But to have Ham to run the case for you, you need to first prepare the correct input file according to what he suggested.He is also busy with his own research. 

  13. Balakrishnan Nagarajan

    Respected Professor Yu,

    Thank you very much for accepting me in this group. It is very impressive for me to see the capabilities of VAMUCH. I have taken up a modelling project which involves generating a RVE with random spherical inclusions (metallic) in a polymer matrix. My aim is to derive the elastic properties of the composite with various volume fractions of the spherical filler material. I would like to use VAMUCH ANSYS interface tool to do it. I have downloaded the zip files, but running VAMFILE.vam through command prompt mode tells me that it requires a special program to open the file or open file from the internet. Can you please help me in this regard? It will be helpful for me to complete my initial project and explore the possibilities to use it further for my PhD. I want to learn and use this tool as soon as possible. eagerly looking for your reply.

    Balakrishnan Nagarajan