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Andy

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Andy last won the day on September 8

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  1. Hi, I am glad it is working. There are a few different ways to do the spring back calculation in Radioss. I would suggest running HyperForm and looking at the options in the engine files it creates and using those same commands. There is a tutorial HF-3070: Springback Analysis. It looks like they are saving a state file (*.sta) at the end of the first simulation and then creating a second analysis and include the *.sta file from the first analysis. To create a state file see the /STATE/DT help and comments. You can either rerun your simulation with the state file outputs included or if you still have your *.rst files created at the end of the simulation you could create a second engine file with the state outputs in it and then run the simulation for a short amount of time. This is how to continue a simulation with a second engine file. How to create a second engine file. If the first engine file is named runname_0001.rad. When creating a second engine file the number is increased by 1 for the next engine file to a maximum of 9999 engine files. So, the second engine file would be named runname_0002.rad. To avoid a warning message, the engine file number should also match the Run Number listed in the keyword, /RUN. Example: First Engine file, TensileTest_0001.rad /RUN/TensileTest/1 5.0 /TFILE 0.005 /ANIM/DT 0. 0.5 /ANIM/TENS/STRESS/MEMB /PRINT/-1000 /DT/NODA/CST 0.9 1e-6 Example: Second Engine file TensileTest_0002.rad with changed options. /RUN/TensileTest/2 10.0 /TFILE 0.0005 /ANIM/DT 0. 0.05 /ANIM/TENS/STRESS/MEMB /PRINT/-10 /DYREL 1.00 0.002 /DT/NODA/CST 0.9 1e-7
  2. I was referring to /IMPDISP. /IMPDISP/FGEO moves a set of nodes from a start location to an end location linearly. Your motion doesn't sound linear so I am guessing /IMPDISP/FGEO would not work. My assumption is that the ball for SPF would be rigid so you could create a /RBODY of the ball mesh. Then on the master node of the /RBODY define 3 /IMPDISP and 3 /FUNCT one for each direction (x, y, z). Each /FUNCT would be a be displacement versus time. Like this, /IMPDISP/1 x displacement # Ifunct DIR Iskew Isensor Gnod_id Frame Icoor 224 X 0 0 2858 0 0 # Scale_x Scale_y Tstart Tstop 1 1 0 0 /IMPDISP/2 Y displacement # Ifunct DIR Iskew Isensor Gnod_id Frame Icoor 225 Y 0 0 2858 0 0 # Scale_x Scale_y Tstart Tstop 1 1 0 0 /IMPDISP/1 Z displacement # Ifunct DIR Iskew Isensor Gnod_id Frame Icoor 226 Z 0 0 2858 0 0 # Scale_x Scale_y Tstart Tstop 1 1 0 0 /GRNOD/NODE/2858 IMPDISP_group_2860_of_NODE 3235 /FUNCT/224 X displacment # Time displacement 0 0 1 0.5 2 1.5 3 3.5 ..... /FUNCT/225 Y displacment # Time displacement 0 0 1 0.5 2 1.5 5 5.5 .... /FUNCT/226 Z displacment # Time displacement 0 0 1 0.5 2 1.5 2.6 4.5 ....
  3. Hi, If you can export your x, y, z data as a function of time. Then you could define 3 /IMPDISP, one for each direction with a time versus displacement function for each direction. Does the ball also need to rotate while translating in the x, y, z? Is this for Incremental sheet forming (or ISF, also known as Single Point Forming) ? Thanks, Andy
  4. Hi, /TRANSFORM/ROT will rotate the initial model but that will not make the ball have an imposed movement during the simulation. I believe in /IMPDISP you need to set Icoor=1 and define a local /SKEW Now the x, y, z DIR are. x= radial direction (r), y= azimuthal angular direction ( θ ) z= longitudinal direction (Z) So you need reorient your local system so that the local z direction is the axis you rotate about. Then set DIR=Y to get rotation. I have attached a sample model. Thanks, Andy rotate_0000.rad rotate_0001.rad
  5. Using LAW42, The Mooney Rivlin parameters C10 and C01 can be used to calculate mu and alpha, mu1=2*C10 mu2=-2*C01 alpha1=2 alpha2=-2 For Neo-Hooken use. mu1=2*C10 mu2=0.0 alpha1=2 alpha2=0.0 Last as suggested by Prakash for Yeoh use LAW94 which was added in RADIOSS 2017.2. Thanks, Andy
  6. Andy

    Reaction Force at Time Zero

    I believe this is caused by using the imposed displacement. If you differentiate your imposed displacement curve you will get a non-zero velocity curve at T=0. Thus RADIOSS has to apply a force to get that initial velocity. You could try an imposed velocity and see if that gives you the zero force at t=0. If not and you have contact then maybe the issue is initial penetrations. Usually the initial force caused by imposed displacements does not change the results later in the simulation as compared to using an imposed velocity.
  7. Andy

    Issue with Mat Law 42

    Hi Jonas, For solid parts using LAW42 it is recommended to use Ismtr=10 in /PROP/SOLID. Is is written in the comments in /PROP/SOLID. This probably won't fix the tied contact problem though. The 1157 warning means that there are slave nodes of your tied contact that are not able to be projected to a master surface so they are removed from the tied contact. Please check and see which nodes this happens with to see if these are the nodes that are not being tied correctly. Thanks, Andy
  8. Andy

    Failure /FAIL/JOHNSON and /FAIL/TAB1

    Hi, No, you do not need to use /fail/johnson and fail/tab1 together to get the effect of the lode angle. The /FAIL/TAB1 includes the effect of stress triaxiality and lode angle. This is Card 3 in /FAIL/TAB1 from the manual and there is an example for solids in the /FAIL/TAB1 manual. To use /FAIL/TAB1 with lode angle you need test data showing the plastic failure strain at different triaxiality values and different lode angles. Do you have this kind of test data? If you only have plastic failure strain versus triaxiality data and no lode angle then you can still use /FAIL/TAB1 with only defining of plastic strain versus triaxiality. The /FAIL/TAB1 manual has an example for shells without lode angle which could also still be used for solids. It really depends on what failure data you have available. For years engineers got reasonable results by just entering one plastic strain at failure in a material law and it didn't matter the stress triaxality or lode angle (for solids). Now there are more advanced methods with the /FAIL options. Going from most basic to more complex, I would rank the failure models like this: Enter 1 plastic strain at failure value in a material law like /MAT/LAW2 or /MAT/LAW36 /FAIL/JOHNSON /FAIL/BIQUAD (nice balance of easy with advanced features) /FAIL/TAB1 To use more advanced failure models you need to have data to use with them. Even so I would start basic and make sure your simulation is reasonable and then move to a more complex model if you have data for that model. Thanks, Andy
  9. Andy

    Issue with Mat Law 42

    I assume the LAW42 material is the disc that is colored and Vertebrae is grey. Are there any warning messages in your *0.out file? Which is part is slave and which part is master? Is there other TYPE7 contact? What material is the vertebrae and what element (they look like tetra) but are they 1st or 2nd order? Thanks, Andy
  10. Andy

    Failure /FAIL/JOHNSON and /FAIL/TAB1

    Hi, /FAIL/JOHNSON and /FAIL/TAB1 are very similar and work on the same basic idea where a plastic failure strain versus stress triaxility curve has to be defined. In /FAIL/JOHNSON the plastic failure strain versus stress triaxility is created by defining the D1, D2 , D3 parameters which are used in the Johnson-Cook equation. In /FAIL/TAB1, the user defines a /FUNCT which represents the plastic failure strain versus stress triaxility curves. In /FAIL/TAB1 you can define different /FUNCT which represent different plastic failure strain versus stress triaxility curves at different strain rates. In /FAIL/JOHNSON the strain rate affect is defined via the D4 parameter input. So you should not need to use both /FAIL/TAB1 and /FAIL/JOHNSON in the same model since they do the same thing. If you have a plastic strain at failure for compresion (trixaility= -1/3) shear ((trixaility= 0) and tension (trixaility= 1/3) then you can do a curve fit to calculate the D1, D2, and D3 paramters. You could also look at /FAIL/BIQUAD which uses two quadratic equations to define the plastic failure strain versus stress triaxility curves and has some built in starting values for some different materials. Thanks, Andy
  11. Andy

    Visualization of Triaxiality Factor

    To calculate stress triaxiality request stress tensor output in the engine output, /ANIM/SHELL/TENS/STRESS/ALL and then you can use HyperView to post process the results and HyperView will calculate the triaxiality from the stress tensor results just like it can calculate Von Mises stress. Thanks, Andy
  12. Andy

    Problems with Radioss in HPc Cluster

    Hi, It would be much easier if you use the script that comes with HyperWorks to launch RADIOSS. Please try this the script then you don't need to do anything about the Intel MPI path as the script sets that for you. /altair/hw/2017/altair/scripts/radioss -v 2017.2.1 modelinput_0000.rad -mpi i -np 48 -nt 1 -hostfile hostfile -mpiargs -genv KMP_AFFINITY=scatter -genv I_MPI_PIN_DOMAIN=auto -genv I_MPI_ADJUST_BCAST=1 -genv I_MPI_ADJUST_REDUCE=2 -genv I_MPI_MPIRUN_CLEANUP=1 -genv KMP_STACKSIZE=400m -genv I_MPI_FABRICS=shm:dapl with a hostfile that contains, more hostfile node1:16 node2:16 Please send the output for this command. A few more things, Can you ssh between the nodes without entering a password? Last, the HyperWorks installation should be accessible to all nodes in the same location by installing on a shared drive or locally in the same place on each node.
  13. Andy

    Problems with Radioss in HPc Cluster

    You first need to verify that you can run RADIOSS outside of slurm. Since you are running the executable directly, I would assume this is caused by an environment variable not being set correctly. The HyperWorks advanced installation guide pdf from Altair connect about other environment variables suggested for running RADIOSS with the Intel MPI. But I would recommend you just use the radioss script that is included with HyperWorks since it sets all those environment variables for you. First try running on one node using without slurm using, /altair/hw/2017/altair/scripts/radioss -v 2017.2.1 modelinput_0000.rad -mpi i -np 8 -nt 1 -mpiargs -genv KMP_AFFINITY=scatter -genv I_MPI_PIN_DOMAIN=auto -genv I_MPI_ADJUST_BCAST=1 -genv I_MPI_ADJUST_REDUCE=2 -genv I_MPI_MPIRUN_CLEANUP=1 -genv KMP_STACKSIZE=400m -genv I_MPI_FABRICS=shm:dapl then make a host file which has format, node:#cores like this, more hostfile node1:16 node2:16 Then try on two nodes using, /altair/hw/2017/altair/scripts/radioss -v 2017.2.1 modelinput_0000.rad -mpi i -np 48 -nt 1 -hostfile hostfile -mpiargs -genv KMP_AFFINITY=scatter -genv I_MPI_PIN_DOMAIN=auto -genv I_MPI_ADJUST_BCAST=1 -genv I_MPI_ADJUST_REDUCE=2 -genv I_MPI_MPIRUN_CLEANUP=1 -genv KMP_STACKSIZE=400m -genv I_MPI_FABRICS=shm:dapl
  14. Andy

    Problems with Radioss in HPc Cluster

    Hi Pohan, I would suggest you verify that your radioss mpi submission command is working correctly outside of Slurm. First, I would recommend using the Intel MPI that ships with RADIOSS instead of another one that is installed on your system. It is located in, altair/hw/2017/altair/mpi/linux64/intel-mpi/bin/ I think this line needs a "-n $SLURM_JOB_NUM_NODES" like this mpiexec -n $SLURM_JOB_NUM_NODES $ALTAIR_HOME/hwsolvers/radioss/bin/linux64/e_2017.2_linux64_impi -i "$INPUT2" -nt 1 Please download the HyperWorks advanced installation guide pdf from Altair connect about other environment variables suggested for running RADIOSS with the Intel MPI. Alternatively, you can use the script located in scripts/radioss that ships with RADIOSS and then you don't need to call mpiexec but instead the command would look something like this, where -np is the number of MPI domains. The documentation for this radioss script in in the RADIOSS help under, RADIOSS, User Guide Run, Options /altair/hw/2017/altair/scripts/radioss -v 2017.2.1 modelinput_0000.rad -mpi i -np 48 -nt 1 -hostfile /var/spool/PBS/aux/50494.admin -mpiargs -genv KMP_AFFINITY=scatter -genv I_MPI_PIN_DOMAIN=auto -genv I_MPI_ADJUST_BCAST=1 -genv I_MPI_ADJUST_REDUCE=2 -genv I_MPI_MPIRUN_CLEANUP=1 -genv KMP_STACKSIZE=400m -genv I_MPI_FABRICS=shm:dapl -noh3d
  15. Hi Roy, To remove this warning, please put the tetra elements in one component and the hex elements in another component. Create a property for the tetra elements and leave Isolid input field blank. We are going to improve this message in the next version as it is confusing to users. Thanks, Andy
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