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Hyperman last won the day on July 7

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About Hyperman

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  1. Hi, just try to run it. It ran fine on my end.
  2. Hi, /PRELOAD keyword can be entered manually: with text editor into starter .rad file analysis>control cards>Unsupported cards
  3. @anqi as can be seen from the animation below, the top of the column (away from impact) decelerates only after the stress wave propagates through the whole length.
  4. Attached is version 14 compatible model which ran fine on my end, regardless of qa and qb parameters. Test2_edit_0000.rad
  5. Glad to help. If gapmin is left blank it will be automatically calculated according to Igap flag. This value can be seen in starter out file by searching "gapmin" keyword. It appears the reason for 99% energy error after impact is a too high minimum gap for contact activation (gapmin) value- I have no explanation why this happens. I have meshed the plate coarsely for computational efficiency during trial runs as we are more interested in SPH behavior than stress distribution- the final model should be refined according to mesh convergence study. Actually, I haven't modified the linear and quadratic bulk viscosity (qa and qb) parameters- they were used in the model you shared. Test2_edit_0000.rad
  6. You have misunderstood- deformable (regular) elements are made non-deformable with a rigid body. Once rigid body is turned off, regular elements will become deformable again. Refer to attached document for more information. Rigid Body (_RBODY).pdf
  7. Hi, It is possible to enter the initial stress values element by element in the Runname_0000.rad file, by using options /INISHE and /INISH3 for shell elements. It is also possible to write with RADIOSS Engine state files Runname_nnnn.sta for shells. Such a file will contain the geometry of selected parts (nodes coordinates and element connectivity), plus cards /INISHE and /INISH3 defining the stress, strain, and so on, of the shells and 3-node shells belonging to these parts.
  8. Hi, There was an issue with gapmin. Please set /INTER/TYPE7 , GapMin= the 1/2 the pitch you used to generate the SPH particles + 1/2 the thickness of the walls. The pitch is the distance between the particles so 1/2 the pitch is the radius : Simulation controls were defined and the plate was modified for computational efficiency. Finished model from birdstrike tutorial is also attached. Test1_edit_0000.rad birdstrike_edit_0000.rad
  9. Hi, There is a description of corner data, its significance and use in the HyperWorks student guide (Practical Aspects of Finite Element Simulation). In page 187 of the student guide, we see an example about stress concentration in a plate with a hole, which is a good example where corner stress results are necessary. By default the element stresses for shell (and solid elements) are output at the element center only. In other words, these stresses are not exactly the ones “existing” at the hole. To better resolve the stresses at the hole, the element stresses are output at the grid points using bilinear extrapolation (in HyperMesh activate the Control cards > Global output request > Stress > Location: Corner). Free e-books can be downloaded at: http://www.altairuniversity.com/free-ebooks-2/
  10. Hi, Put a rigid body on finer mesh and turn it off just before the impact with a sensor. Rigid bodies can be activated or deactivated with a sensor or with the options /RBODY/ON and /RBODY/OFF in the Engine files. To activate two rigid bodies with the master node 1 and 2, add the following option in Rootname_0001.rad: /RBODY/ON 1 2 All elements included in both rigid body are deactivated. To deactivate one rigid body whose master node ID is 3, add: /RBODY/OFF 3 All elements are reactivated, strains and stresses are those from previous deactivation time. Contact interfaces can be turned on/off with Tstart and Tstop parameters. Use additional engine files (runname_0002.rad) to change simulation settings during the run. Refer to example RD-E: 1200 Jumping Bicycle for more details. Analysis and Model Description.pdf
  11. Hi, it is expected segments away from the impact zone will experience delayed deceleration. can you share slow motion animation (gif format) with many frames per second?
  12. Hi, the shared model had some issues: unit consistency: input units were defined as kg, m, s in the begin card, but initial velocity and material (steel?) had values more consistent with tonne, mm, s unit system impactor with 34000 mm/s (122.4 km/h) initial velocity and 450 kg mass has too much initial kinetic energy for the plate to absorb animation output frequency (ANIM/DT) was too low to capture deformations contact was modified The model is able to solve with failure plastic strain (EPS_p_max) defined. Without material fracture the model will fail to solve as the loading is so high the plate will undergo unrealistic deformations causing numerical difficulties. Impact test-tutorial_edit.hm Impact_test-tutorial_edit_0000.rad Impact test-tutorial_edit_0001.rad
  13. Hi, To apply load in a number of steps in Optistruct use nonlinear quasistatic analysis. The number of steps is defined through NINC parameter in NLPARM load collector. Results data such as stress etc. can be requested through the GLOBAL_OUTPUT_REQUEST (Setup>Create>Control Cards) or for each subcase through subcase options>output. Chair4_MG
  14. Modal participation factors are output by default from Motionsolve when flexible bodies are included. They can be plotted in HG using either mrf of abf files. _mbd.mrf file.pdf
  15. Hi, the error is due to roof component ID 6 being referenced by GRPART ID 9 for DTPL/1 and DRESP1/1, but not being referenced by GRPART ID 11 for ESLPART. HopperOpt_0000.rad
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