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Everything posted by Shrinaath

  1. HI IVAN thanks can u share me the modified model with ideal time step...
  2. sorry simulation is not yet completed. i have shared the _0000.rad & _0001.rad file with you please verify with it this is my loading curve, is this not appropriate 2D_SHELL.h3d
  3. please find the files 2D_SHELL_0000.out 2D_SHELL_0001.out 2D_SHELLT01
  4. thanks ivan i tried with time step DT/NODA/CST 0.144E-02 i am having mass error and energy error as follow RESTART FILES: 2D_SHELL_0001_[0001-0001].rst WRITTEN NC= 605000 T= 8.7604E+02 DT= 1.4481E-03 ERR=-60.0% DM/M= 3.2230E-02 ELAPSED TIME= 1579.40 s REMAINING TIME= 304910.89 s NC= 605500 T= 8.7676E+02 DT= 1.4481E-03 ERR=-60.0% DM/M= 3.2230E-02 ELAPSED TIME= 1580.85 s REMAINING TIME= 304938.64 s NC= 606000 T= 8.7749E+02 DT= 1.4481E-03 ERR=-60.2% DM/M= 3.2230E-02 ELAPSED TIME= 1582.20 s REMAINING TIME= 304945.54 s NC= 606500 T= 8.7821E+02 DT= 1.4481E-03 ERR=-60.3% DM/M= 3.2230E-02 ELAPSED TIME= 1583.49 s REMAINING TIME= 304941.06 s NC= 607000 T= 8.7894E+02 DT= 1.4481E-03 ERR=-60.4% DM/M= 3.2230E-02 ELAPSED TIME= 1584.80 s REMAINING TIME= 304941.00 s NC= 607500 T= 8.7966E+02 DT= 1.4481E-03 ERR=-60.5% DM/M= 3.2230E-02 ELAPSED TIME= 1586.16 s REMAINING TIME= 304950.37 s ANIMATION FILE: 2D_SHELLA045 WRITTEN NC= 608000 T= 8.8038E+02 DT= 1.4481E-03 ERR=-60.6% DM/M= 3.2230E-02 ELAPSED TIME= 1587.61 s REMAINING TIME= 304976.63 s NC= 608500 T= 8.8111E+02 DT= 1.4481E-03 ERR=-60.7% DM/M= 3.2230E-02 ELAPSED TIME= 1588.93 s REMAINING TIME= 304978.07 s NC= 609000 T= 8.8183E+02 DT= 1.4481E-03 ERR=-60.8% DM/M= 3.2230E-02 ELAPSED TIME= 1590.30 s REMAINING TIME= 304988.53 s
  5. hi i having problem in time step. i checked the minimum time step in the model that comes around 1.934e-03. when i run the model in radioss with out mass scaling it takes the DT= 0.1448E-02. but usually the minimum time step * 0.9 will be taken in radioss as initial time step, when we calculate that 0.001934 * 0.9 = 0.0017406 what is reason behind this
  6. Hi @Ivan i facing problem during running the job that my simulation remaining time is keep on increasing with error percentage. i attached the text file ERROR.txt for reference. does the model have any issue in the contact?? i have attached my model file please check 2D_SHELL_0000.rad 2D_SHELL_0001.rad 2D_SHELL_0002.rad
  7. thanks your reply i will read those journals. i am having a doubt does MAT36 will used for the springback analysis??
  8. hi, if we use the damping for controlling the vibration in the plate, does it affect the spring back???
  9. hi @Ivan i will do some iteration on this Rayleigh damping coefficient and lets u know if i had any difficulties..... i having doubt in the spring back i used the implicit spring back option as mentioned in the example 25 but my results are not that much correlating . In implicit spring back what kind of solver should we use in tutorial it mentioned /IMPL/SOLVER/2 but in the file which is mentioned in the tutorial DBEND_44 they mentioned /IMPL/SOLVER/1 i have attached the tutorial and file from tutorial for reference. DBEND_44_0002.rad
  10. hi @ivan thanks for your reply. In Rayleigh damping (/DAMP) how to find the values of alpha & beta. And if i apply the values for alpha and beta means the time step which i imposed through Advance Mass Scaling (/AMS) is not taken into consideration.The simulation runs on with the actual time step... What is the reason behind this issue.
  11. hi @Ivan simulation works fine but the plate (2D shell model) is vibrating much. i have applied load gradually. what might be the issue in the model . refer the 1PASS.avi video i have attached.
  12. Hi @Ivan thank you, its clear...... energy error% it is goes on increasing CYCLE TIME TIME-STEP ELEMENT ERROR I-ENERGY K-ENERGY T K-ENERGY R EXT-WORK MAS.ERR 2447500 2985. 0.1239E-02 NODE 27 -89.9% 230.2 9.932 5.925 2448. 0.000 ANIMATION FILE: 2D_SHELL_A5972 WRITTEN 2448000 2986. 0.1239E-02 NODE 27 -90.0% 229.3 10.88 5.927 2449. 0.000 ANIMATION FILE: 2D_SHELL_A5973 WRITTEN ANIMATION FILE: 2D_SHELL_A5974 WRITTEN 2448500 2987. 0.1239E-02 NODE 27 -90.0% 228.4 11.67 5.930 2450. 0.000 ANIMATION FILE: 2D_SHELL_A5975 WRITTEN 2449000 2987. 0.1239E-02 NODE 27 -90.0% 227.7 12.38 5.935 2450. 0.000 ANIMATION FILE: 2D_SHELL_A5976 WRITTEN 2449500 2988. 0.1239E-02 NODE 27 -90.0% 227.0 12.98 5.919 2451. 0.000 ANIMATION FILE: 2D_SHELL_A5977 WRITTEN i didn't specify any mass scaling /DT/NODA/CST or /DT/AMS
  13. hi @Ivan i am simulating the manufacturing process 3 roll bending process in radioss, early i used 3D model now i am trying with a 2D model, since plate thickness 3 mm For that i extracted the midsurface of the plate and assign the thickness of the plate as 3mm. i used P1_shell ishell=24 N=5 thick=3 Istrain=1. i assigned the material property to roll and plate, boundary condition, contact every thing as same. shell is bending only in the region inside the rolls, region outside the roll is not bending i have marked in the image . does i have used any shell parameters wrongly. i having problem in imposed velocity also that the rotation of roller. the roller is not rotating in both the direction i have assigned negative sign(-) to change the direction of roller in curve editor. i have attached my file pls check thanks 2D_SHELL_0000.rad 2D_SHELL_0001.rad
  14. hi what is the reason in elastic-plastic material like MAT36 we should use the effective stress-strain curve thanks
  15. hi thanks for replay some where in unit system, element length & time step i might have made mistake i think i used ton mm mpa s unit system i made mistake in density it is 2.63e-9 please change that and check the model file... bend_0001.out
  16. hi remaining time is increasing there is no convergence is this might be because of element size??? i have done same simulation by applying steel property now i changed to aluminium this might because of time step and element size bend_0000.out bend_0000.rad bend_0001.rad
  17. hi i am getting an error what is the problem behind this my simulation goes on like this ELAPSED TIME= 451.37 s REMAINING TIME= 238056.46 s NC= 9500 T= 5.9868E-02 DT= 5.8914E-06 ERR= -0.5% DM/M= 0.0000E+00 ELAPSED TIME= 476.10 s REMAINING TIME= 238100.41 s RESTART FILES: bend_0001_[0001-0001].rst WRITTEN NC= 10000 T= 6.2957E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00 ELAPSED TIME= 500.97 s REMAINING TIME= 238219.10 s NC= 10500 T= 6.6150E-02 DT= 5.8914E-06 ERR= -0.6% DM/M= 0.0000E+00 ELAPSED TIME= 529.13 s REMAINING TIME= 239438.85 s NC= 11000 T= 6.9340E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00 ELAPSED TIME= 557.75 s REMAINING TIME= 240755.26 s NC= 11500 T= 7.2549E-02 DT= 6.4528E-06 ERR= -0.6% DM/M= 0.0000E+00 ELAPSED TIME= 584.23 s REMAINING TIME= 241002.99 s NC= 12000 T= 7.5685E-02 DT= 6.1558E-06 ERR= -0.6% DM/M= 0.0000E+00 ELAPSED TIME= 612.67 s REMAINING TIME= 242236.66 s
  18. hi pranav hari thanks for ur reply. i have one more doubt during first pass material undergoes plastic deformation so that material properties of plate will change during first pass, does the change of properties will be taken into account if we do like this?????
  19. hi pranav hari if i do like this means does i need to assign the boundary condition, material laws etc to this model then the material behavior will change know i need the results like stress and strain in first pass should carried to second pass
  20. hi ivan is type 21 is for shell element in type21 unable to select the slave as brick element for arresting the dof's i try one method i created an second engine file to arrest DOF's of the component at a specific time by adding these commands /BCS/TRA/XYZ node numbers simulation get terminated because of mass error releasing the dof's is fine works well is there any similar way for arresting the dof's
  21. hi pranav hari sure i need to apply the displacement at the same point (middle of the plate) where first displacement is applied. i have checked with Tstart/Tstop parameter for boundary constrain it is not working. is there any other way.... in this topic they have used the second engine file..... thanks Multiple_pass_0001.rad Multiple_pass_0000.rad
  22. hi ivan can u explain me briefly about Tstart/Tstop parameter i need to fully constrain the plate at the specific time i have created constrain for this as in the image is that an appropriate way. when i am running this i am getting the warning as a incompatible kinematic condition and it simulated is get stopped. thanks
  23. hi pranav hari can we start the simulation with the deformed model in the previous simulation with exact stress and strain state?????
  24. hi pranav hari thanks for your reply my work is simulation of 3 point roll bending in that top roller is moved in vertical direction and bend the plate then the peripheral velocity is given to the roller to bend the plate all over its length. i am trying to do more detailed way by apply small displacement and rolling the plate then again apply the displacement and roll the plate. i have done simulation for the first displacement and first pass it working properly i am having problem in the second displacement. i need to apply the second displacement at the same point of the plate where the first displacement is applied on the plate, since it is time dependent i cant able to position the same point because of friction and slip between plate and the roll. is there any other way to do this second displacement by taking the first pass results and positioning the plate then run the simulation. please check the files. thanks. roll_bending.avi
  25. Hi i am doing 3 point roll bending simulation in that i need to gradually increase the top roller displacement (i.e) at first stage top roller displacement is given as 2 units then the plate is rolled. After this i need to apply the top roller displacement at the same point on the plate and again rolling need to be done. since it is having friction and slip i cant able to find position at the exact point. is there any way to do by creating a separate engine file or any other way like .sta file thanks Shrinaath
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