Assignment of initial stress using .sty file

Kohta Ito_21106
Kohta Ito_21106 Altair Community Member
edited November 2021 in Community Q&A

Hi.

I'm trying to input the initial stress for solid element and initial velocity for nodes using .sty file generated during prior calculation.

/OUTP/BRIC/STRES/FULL

/OUTP/VECT/VEL

were utilized for the output, respectively.

 

To check whether the stress and velocity values are correctly input to the model, we compare the results written in .sty file of first and second running.

However, we confirmed there were different stress values in the same solid element.

[First running]

/SOLID /TENSOR /STR_FUL
Full stress tensor + plastic strain
#FORMAT:(NPT, ISOLNOD (2I10/2E20.13), EINT(I),RHO(I),,I=1,NUMSOL
#FORMAT: (1P6E20.13/E20.13) ((TX(I,J),TY(I,J),TZ(I,J),TXY(I,J),TYZ(I,J),TZX(I,J),
#EPSP(J,I),J=1,NPT),I=1,NUMSOL,NPT=1)
1 4
-6.7621997110738E-07 1.4999960395455E-03
7.5204702163451E-02-3.8801280336932E-02 1.1782171715919E-02 3.1060056356859E-02-1.6245572187241E-02-2.6996609790200E-02
0.0000000000000E+00

 

[Second running]

/SOLID /TENSOR /STR_FUL
Full stress tensor + plastic strain
#FORMAT:(NPT, ISOLNOD (2I10/2E20.13), EINT(I),RHO(I),,I=1,NUMSOL
#FORMAT: (1P6E20.13/E20.13) ((TX(I,J),TY(I,J),TZ(I,J),TXY(I,J),TYZ(I,J),TZX(I,J),
#EPSP(J,I),J=1,NPT),I=1,NUMSOL,NPT=1)
1 4
-6.7621997110738E-07 1.4999960395455E-03
-2.8076925403528E-07-2.1057678031223E-17 2.8076925396508E-07 0.0000000000000E+00 0.0000000000000E+00 0.0000000000000E+00
0.0000000000000E+00

 

 

On the other hand, initial velocity looks successfully assigned.

 

We've already checked some Q&A in the forum about stress initialization, but still not found the solution.

Can anyone give some tips about this problem?

Thank you in advance.

 

 

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Answers

  • Rogerio Nakano_21179
    Rogerio Nakano_21179 New Altair Community Member
    edited November 2021

    Hi

    one suggestion is to use the *.sta file, generated by the /STATE/DT option.

     

    Regards

     

  • Kohta Ito_21106
    Kohta Ito_21106 Altair Community Member
    edited November 2021
    Rogerio Nakano_21179 said:

    Hi

    one suggestion is to use the *.sta file, generated by the /STATE/DT option.

     

    Regards

     

    Thank you for your reply.

    Could you tell me the way to define initial velocity of each nodes using *.sta file?

    Our model consists of over 90000 nodes and each has a different velocity, but it is hard to define initial velocity to every nodes using /INIVEL card.

    On that point, *.sty file was easy to define initial velocity of each nodes.

    Thanks.

     

  • Kohta Ito_21106
    Kohta Ito_21106 Altair Community Member
    edited November 2021

    I've also tried based on *.sta file, but the same problem was observed.

     

    Starter file of second running was created using HyperMesh as the following procedure.

    Import starter file of first running -> import *.sta file of first running (model was overwritten) -> output

     

    This time, strain and stress of solid element were output using following keywords.

    /STATE/BRICK/STRES/FULL
    /STATE/BRICK/STRAIN/FULL

    Then the stress and strain values in the *.sta file of first and second running were compared .

     

    [First running]

    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    /INIBRI/STRS_F
    #------------------------ REPEAT ------------------------
    # BRICKID NPT ISOLNOD JJHBE
    # IF (NPT /= 0) REPEAT K=1,NPT : REPEAT I=1,NPG :
    # EINT, RHO
    # S1, S2, S3
    # S12, S23, S31
    # EPSP
    #---------------------- END REPEAT ---------------------
    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    2495261 1 4 1 1 1 1
    -4.8826642324484E-06 1.5000008777421E-03
    1.8449520985740E-02-2.8361860847607E-02-7.6685222072587E-04
    -4.1188984487813E-03 3.5222010050022E-03 3.7224890122514E-03
    0.0000000000000E+00

    [Second running]

    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    /INIBRI/STRS_F
    #------------------------ REPEAT ------------------------
    # BRICKID NPT ISOLNOD JJHBE
    # IF (NPT /= 0) REPEAT K=1,NPT : REPEAT I=1,NPG :
    # EINT, RHO
    # S1, S2, S3
    # S12, S23, S31
    # EPSP
    #---------------------- END REPEAT ---------------------
    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    2495261 1 4 1 1 1 1
    -4.8826642324484E-06 1.5000008777421E-03
    -2.8076925403528E-07-2.1057678031223E-17 2.8076925396508E-07
    0.0000000000000E+00 0.0000000000000E+00 0.0000000000000E+00
    0.0000000000000E+00

     

    As shown above, the resultant stress values of first running were not successfully reflected to the second running model.

    On the other hand, strain values were successfully taken over.

     

    [First running]

    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    /INIBRI/STRA_F
    #------------------------ REPEAT -------------------------
    # BRICKID NPT ISOLNOD ISOLID
    # IF(NPT /= 0) REPEAT K=1,NPT
    # E1, E2, E3
    # E12, E23, E31
    #------------------------ REPEAT -------------------------
    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    2495261 1 4 1
    6.0011474898252E-06-3.3494141151046E-06 3.1136129625029E-06
    -1.7766252106441E-06 1.2995978381205E-06 5.8994638203099E-07

    [Second running]

    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    /INIBRI/STRA_F
    #------------------------ REPEAT -------------------------
    # BRICKID NPT ISOLNOD ISOLID
    # IF(NPT /= 0) REPEAT K=1,NPT
    # E1, E2, E3
    # E12, E23, E31
    #------------------------ REPEAT -------------------------
    #---1----|----2----|----3----|----4----|----5----|----6----|----7----|----8----|----9----|----10---|
    2495261 1 4 1
    6.0011474898252E-06-3.3494141151046E-06 3.1136129625029E-06
    -1.7766252106441E-06 1.2995978381205E-06 5.8994638203099E-07

     

    I would appreciate it if someone would give me some advice.

    Thanks.

     

  • Rogerio Nakano_21179
    Rogerio Nakano_21179 New Altair Community Member
    edited November 2021
    Kohta Ito_21106 said:

    Thank you for your reply.

    Could you tell me the way to define initial velocity of each nodes using *.sta file?

    Our model consists of over 90000 nodes and each has a different velocity, but it is hard to define initial velocity to every nodes using /INIVEL card.

    On that point, *.sty file was easy to define initial velocity of each nodes.

    Thanks.

     

    you can save node velocities into the *.sta

     

    https://2021.help.altair.com/2021.2/hwsolvers/rad/topics/solvers/rad/state_node_vel_engine_r.htm

     

    Regards

  • Kohta Ito_21106
    Kohta Ito_21106 Altair Community Member
    edited November 2021
    Rogerio Nakano_21179 said:

    you can save node velocities into the *.sta

     

    https://2021.help.altair.com/2021.2/hwsolvers/rad/topics/solvers/rad/state_node_vel_engine_r.htm

     

    Regards

    Dear Rogerio,

     

    Thank you for your reply again.

    It'll be so helpful and I'll try it.

     

    When I used *.sta file, the same problem has been occurred which I encountered when I used *.sty file.

    Details were written down below.

    Could you give any advices about that?

    Thanks.

     

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