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  1. slimjimmy

    5 cutbacks at start of new step - cutback reason "material point calculations"

    Hi everyone, I'm running a analysis with 4 forming steps. The model runs fine up to the 4th step. At the start of the 4th step, I get 5 cutbacks on the first increment. In Job diagnostics the cutback reason is "material point calculations". To debug, I have added in dummy 4th step with no...
  2. slimjimmy

    Python script - permission error in calling another python file

    Hi, I'm running a basic python script through the scripting interface in Abaqus. In the script another python file is called which operates on a element stresses previously outputted into a text file. The script runs fine on windows, however I have recently changed to Ubuntu and am now having...
  3. slimjimmy

    Modelling inflation of a sheet using Holzapfel (HGO) model

    Hi Everyone, I'm am preforming a simple analysis whereby I'm inflating a thin rectangular sheet of tissue using the built in Holzapfel (HGO) model. The sheet is constrained in 3 dof on three sides and unconstrained on the remaining side. A pressure load is applied to the inner face to inflate...
  4. slimjimmy

    Numerical problems associated with large differences in mechanical properties

    Hi Everyone, I am having difficulties running my models in abaqus. I think it is due to some mass scaling issues as I have large differences in mechanical properties between different parts of my model. Can someone help me out with some insight/documentation that can explain numerical issues...
  5. slimjimmy

    Connecting two nodes togther

    Hi Guys, I am running an analysis to attach two nodes togther. In step 1 I am displacing a node X to a Node Y such that both are in the same position at the end of the step. In the second step i want to tie constrain them such the if I move node Y node X will be attached and follow it. I have...
  6. slimjimmy

    Mass Scaling ABQ/Explicit Artery-Stent contact

    Hi Everybody. I'm modelling Nitinol stent crimp and expansion into an idealised artery in Abaqus/Explicit. I am having numerous problems with the ratio of kinetic energy to internal energy with the analysis. I was hoping somebody may provide me with some insight on this. I am modelling the...
  7. slimjimmy

    Understanding node numbers

    Hi, You can make abaqus CAE write your input files such that only one single part is produced. For example you have two parts, the first part goes from node 1 - 54 and the 2nd from 1 - 63. You can tell abaqus to combine your parts such that the first part will have nodes 1 - 54 and the 2nd part...
  8. slimjimmy

    Unwrapping a stent cylindrical mesh

    Hi Guys, I have a stent (cylinder like) mesh and I want to edit some features. Does anybody know of a way to "unwrap" this mesh from its cylinder like form to a planar form. Any help would be great cheers
  9. slimjimmy

    Applying Boundary condition to a node in an input file

    Thanks Guys, I got it working in the end, using a hyperworks mesh input file. I think Mech Ireland is right, you need to reference an instance each time you reference a node for a BC.
  10. slimjimmy

    Applying Boundary condition to a node in an input file

    Hi Guys, How do you apply a boundary condition to a specific node in an Abaqus input file? When an input file is generated a set is created for each node. Here is an example ** BOUNDARY CONDITIONS ** ** Name: BC-1 Type: Displacement/Rotation *Boundary *_PickedSet5, 1, 1, 0.1 *_PickedSet5, 2...
  11. slimjimmy

    FEA sensitivity and probabilistic analysis of bone fracture fixation

    Hi hubihubi, Perhaps these papers may be of use, http://eprints.soton.ac.uk/143233/1/paper_3_proof.pdf You should also check out her other papers. Hope this may help
  12. slimjimmy

    Applying nodal displcaments from one mesh to another

    Hi Guys, I have two mesh models, one in a reference unloaded geometry and the other in a loaded geometry. I want to add a further part to these meshed models such that i can look at the stress on this part due to the deformation of the previous meshed part. However the problem i have is...
  13. slimjimmy

    UANISOHYPER STRAIN help

    I have just noticed that the ebar variable (modified green strain - variable to be passed in by abaqus) is not updating from one iteration to the next. If i assign an arbitrary value to ebar the umat runs but still errors except this time without the "unexpected error 193" Is there any...
  14. slimjimmy

    UANISOHYPER STRAIN help

    Hi Biobio, Cheers for the reply, I'm still stuck on this! I noticed your first correction straight away and changed it as you said, but still to no avail. I didnt use UA2. My reason being the documentation says this is the deviatoric part of the strain energy function,I however am just...
  15. slimjimmy

    UANISOHYPER STRAIN help

    Any ideas Guys?
  16. slimjimmy

    UANISOHYPER STRAIN help

    Hi Guys, First time poster here. Im writing a UMAT to implement the fung elastic model into abaqus. The equation is U=c/2(e^^Q -1) and Q is int terms of the material coefficients of the strain components Eij. Im using the UANISOHYPER Strain in abaqus, and what i need to define is U - the...

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