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Recent content by rmettier

  1. rmettier

    How can I avoid intersecting parts?

    *g* yes, I have slightly more than 2 parts. 15 parts in a complex geometry forming 25 contact surfaces (think pack-ice). The entire purpose of the model is to push one part and see how the others move in response. I'll look into your idea of nudgeing each part into the others in a seperate...
  2. rmettier

    How can I avoid intersecting parts?

    Ah, right...that makes sense, thank you. I've tried this, but to no avail. I use a linear amplitude, which goes from 0 to 1 over 36'000 seconds, and a small displacement of 10km along the top of the model. The bottom is fixed. Runs fine for the first few increments, then suddenly the parts...
  3. rmettier

    How can I avoid intersecting parts?

    Not quite sure what you mean with 'fixed displacement'. Do you mean a displacement boundary condition applied to the entire model with displacements set to zero?
  4. rmettier

    How can I avoid intersecting parts?

    Ok, so no luck...don't see any difference. I've now tried changing the constraint enforcement method of the normal behaviour in the interaction property definition from default to augmented Lagrange, so I can adjust the penetration tolerance in the contact controls. A relative tolerance of 0.01...
  5. rmettier

    How can I avoid intersecting parts?

    Actually, in the most obvious case, the slave surface (meshed at 1000m mesh size) is moving through the master surface (meshed at 5000m). Slave surface is also the softer material (barely). Trying with automatic tolerance in contact controls now. I'll let you know if it helps. Btw, thanks for...
  6. rmettier

    How can I avoid intersecting parts?

    Ok, so I tried converting the model to run in standard (whew, lot of work), but it doesn't really help much. I now have all the interactions defined as: Discretization method: surface-to-surface Sliding formulation: finite sliding Adjust only to remove overclosure Contact Controls: default...
  7. rmettier

    How can I avoid intersecting parts?

    Ok, so I tried converting the model to run in implicit (whew, lot of work), but it doesn't really help much. I now have all the interactions defined as: Discretization method: surface-to-surface Sliding formulation: finite sliding Adjust only to remove overclosure Contact Controls: default...
  8. rmettier

    How can I avoid intersecting parts?

    Corus: Thanks for your reply. I checked, and you're right, some of the parts are actually overlapping minimally at the beginning of the analysis, although why is unclear, seeing as I defined each part vertice directly by coordinates (maybe something to do with the meshing). I combed the manual...
  9. rmettier

    USERSUBROUTINEs

    great to see you cracked the problem. Maybe you could provide the fixed code as an example for those still fighting with the same issues you had?
  10. rmettier

    How can I avoid intersecting parts?

    Here's some background into the model I'm trying to run: This is a fairly large scale geological setting, done in 2D using Abaqus Explicit (6.8-3)and CAE. See attached file for a zoomed out view of the relevant bits. At this step, the parts are just settling under their own weight, and jostling...
  11. rmettier

    Random variations of material properties in CAE?

    Hmmm, that's what I dreaded. I've spent quite a while trying to understand the example for UMAT in the manual, and I'm afraid it's simply gibberish to me. Isn't there some way of assigning materials to element sets directly? I ask because it's fairly easy to modify the input file to divide the...
  12. rmettier

    Random variations of material properties in CAE?

    Hi I'm using Explicit to model some geodynamic stuff, and I've reached the point where perfectly homogeneous materials are becoming a problem. What I'd like to do is have an elastic definition for, say, granite with (E=53GPa, v=0.28) and then add a small random deviation to Youngs modulus...
  13. rmettier

    ODB Postprocessing - Coordinates relative to a node?

    I have a model step over which i need to plot the motion of a part of my model. The step has 100 timesteps, and I have COORD set as a field output. So I'm using the 'create field data' tool, and creating a new field from existing fields as "s3f100_COORD-s3f0_COORD". So far, it's working, but...
  14. rmettier

    Multiple layers with frictional sliding in between them

    Don't know if this helps, but I've had similar problems with large scale models, and it was also due to the sliding conflicting with the interaction definition. In the interaction definition you have define that there can be now seperation after contact. Now if a corner node of a surface slides...
  15. rmettier

    Changes in friction having no effect?

    I've set up a simple 2D test model to see if I could isolate the problem, and here's what I've observed: The test model consists of only two parts, one part (ramp) is a simple ramp shaped object, with purely elastic material definitions. The second part (block) is a wedge shaped object laying...
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