Soil and Rotavator Blade analysis

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

Hi Sir,

 

I have College project in which i have analyse a Rotary Tiller Blade.

That is .... a Single blade rotating about an axis  and striking the compacted soil surface.

 

Kindly guide me What material configuration should i use in order to model a 

compacted soil block in hypermesh 

 

For reference attached is the image of tiller<?xml version="1.0" encoding="UTF-8"?>post-33500-0-08207000-1417962382_thumb.j

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Answers

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Hi Paramveer,

     

    in order to model soil material, consider using LAW20 (Bi-material).

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    hi,

     

    IS LAW20 available in Hyperworks 11,

     

    moreover I can not find it in RADIOSS theory manual

     

    Regards:

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Hi Paramveer,

     

    Yes it is.

     

    You can also consider LAWs 10 and 21.

     

    Please refer to theory manual for more information on above two material models.

    <?xml version="1.0" encoding="UTF-8"?>post-7616-0-60466200-1418620731_thumb.jp

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Thankyou for your support as always.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    HI prakash,

     

    I am unable to understand the input parameters for LAW10

    like.... A0,   A1,   A2......A max     etc.

    as in my perspective these inputs are experimental data....

     

    though the Theroy manual is informative

    still I am unable to understand

     

    if possible kindly provide the tutorial for the same....

    or provide a set of diffrent type of soil material data/library.

     

    thankyou.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Hi Paramveer, 

     

    Please check the image below:

     

    <?xml version="1.0" encoding="UTF-8"?>post-7616-0-90981400-1419222207_thumb.jp

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Hi Prakash,

     

    1) can you let me know what type of Property definition to be used for soil model.

     

    2) while defining the MLAW 10 or MLAW 21, i need to define Amax......inorder to simulate failure criterion

    so what could be the possible value. 

     

    3) as per your previous thumbnail... for loose soil Tau0=0

    what if the tau 0 is not equal to zero.

     

    4) sending you few calculation thumbnail and model file(sent through secure dropbox)

     

    for reference attached is the some materials data 

     

    thanks

    <?xml version="1.0" encoding="UTF-8"?>post-33500-0-16154400-1419943395_thumb.j

    <?xml version="1.0" encoding="UTF-8"?>post-33500-0-44001100-1419943723_thumb.j

    <?xml version="1.0" encoding="UTF-8"?>post-33500-0-70255800-1419946587_thumb.j

    <?xml version="1.0" encoding="UTF-8"?>post-33500-0-58928000-1419946601_thumb.j

    Unable to find an attachment - read this blog

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited December 2014

    Hi Paramveer,

     

    LAW 10 is compatible with solid elements only.

     

     

    See the plot image below on how to get Amax value.

     

    If Tau0 is not equal to zero then there is a cohesive strength exits (as per your document)

     

     

     

    <?xml version="1.0" encoding="UTF-8"?>post-7616-0-53887000-1420009767_thumb.jp

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2015

    Hi prakash,

     

    what type of interface is to be defined in this case....

     

    moreover do i need to define contact surface??????

     

    thanks??

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2016

    Hi Prakash,

     

    Can you please let me know the reference for the below mentioned image which contains the information on how to find the A0, A1 and A2 parameters for LAW10. 

     

    Hi Paramveer, 

     

     

     

     

    Please check the image below:

     

     

     

     

     

    <?xml version="1.0" encoding="UTF-8"?>post-7616-0-90981400-1419222207_thumb.jp

     

     

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited January 2016

    Hi Sai,

     

    That was published online, I think. I am not sure which website, though.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Prakash,

     

    I am trying to model soil in RADIOSS and I have used the equations as given above to find the yield coefficients A0, A1 and A2. The results I am getting are different from the actual properties. Can you give more insight on how J2 coefficients are calculated. I am unsure of the equation you have given for J2 because the curve given below (J2 vs P curve) can never occur for equation given by J2 = 1/3*(alpha^2*P^2- 2alpha^2*t0*P/tan(alpha) + alpha^2*t0^2/tan^2(alpha), since the P^2 coefficient is positive. Also, Is J2' the same as J2 in that text?

    post-7616-0-53887000-1420009767.jpg

    Also, Can you kindly guide what property to use for modeling soil in RADIOSS. I am currently using P14_SOLID with Isolid=24 and ismstr = 10. Please let me know if there is any better property. Further, is it advisable to have coarse mesh or fine mesh for modeling soil?

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited February 2016

    Hi Sai,

     

    Can you check with this following Alpha?

     

    Also, can you plot for (J2)^1/2 Vs Pressure instead and check if that fits?

     

    You can use Brick, tetra, thick shell elements which are compatible with LAW 10.

    <?xml version="1.0" encoding="UTF-8"?>Capture.JPG