Continue to Site

Eng-Tips is the largest engineering community on the Internet

Intelligent Work Forums for Engineering Professionals

  • Congratulations MintJulep on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!

Search results for query: *

  1. MaddogMcCree

    Plastic failure criteria

    Material failure at 6% elongation probably comes from a tensile testing. Be careful there as this failure is due to the geometry of the tensile specimen and not a failure characteristic to the material itself. I would propose you to go by MAT_ADD_EROSION (from 9.71 R5 on well documented). As...
  2. MaddogMcCree

    Dyna-material capable of negative plastic strains?

    Is there a material model in LS-Dyna which can deal with plastic tangent moduli higher than the elastic young´s modulus? An increase in material stiffness results in negative plastic true strains. Using it as input for MAT_24, negative plastic true strains are ignored and set to zero. Can you...
  3. MaddogMcCree

    Initial Stress in LS-Dyna

    Hey there, I´d like to simulate a composite material with matrix and fibres in a prestressed condition (due to different CTE). Therefore I have to take into account that the material´s response due to the stressed condition changes with the amount of prestress. In Ansys there´s the command...
  4. MaddogMcCree

    LS-Dyna material with 2 youngs-moduli

    Hey there, I m looking for a way to simulate a material in LS-DYNA with two different youngs-moduli (one for tension, one for compression). Furthermore it should have two different yield points (one for tension, one for compression). Please see also the image attached...
  5. MaddogMcCree

    Free BC with body force problem

    Never trust a chinese =) A chinese gave me the advice with the body force. It turned out to be totally wrong. I now use "predefined field" as load and it works all fine. Thanks for your help, this thread can get closed. Best regards, Maddog
  6. MaddogMcCree

    Free BC with body force problem

    Thermal Simulations are always a funny tihng, you are right. I need to get my hands on some examples. I thought that a simple generic example would do it. And 100 Kelvin are not a force, that s right. I don t know why ABAQUS calls it "body force". Thanks for your help. Yet maybe someone...
  7. MaddogMcCree

    Free BC with body force problem

    The 100K should lead to a volumetric expansion, i.e. linear expansion in all dimensions. And the boundary conditions are chosen (in my opinion) in a way that free expansion without stresses should be possible (given a homogeneous material).
  8. MaddogMcCree

    Free BC with body force problem

    Hah, sorry. I m using ABAQUS 6.8-4.
  9. MaddogMcCree

    Free BC with body force problem

    Hey guys (and girls :), i d like to simulate thermal stresses in a hybrid material consisting of several different materials. Static Analysis is all fine and yields nice results. Now for a thermal analysis i d like do some research on the thermal expansion and on the resulting stresses. To...
  10. MaddogMcCree

    Interpolation Issue?

    Thank you for all your help. I think the quiltet plot option is a real good idea. For the beginning this one will satisfy me. Yet there still remain some negative values. The resulting contour-plot with the quiltet option is much more reasonable now. The best way maybe is a results-mapping...
  11. MaddogMcCree

    Interpolation Issue?

    Thanks for your response. It s just as I supposed. But how can I overcome it? The values of the contour plot are definitely not the right ones. I thought of deleting all layers except one to have the interpolation performed on only one layer without disturbing high differences in the values...
  12. MaddogMcCree

    .odb section deletion

    Hi, I have a simulation model consisting of several layers which are divided into sections. In the odb.-file, I´d like to chose some of the sections and save them into a new odb-file. My problem is, that a fieldOutput that I implemented has values for the layers that are too different to...
  13. MaddogMcCree

    Interpolation Issue?

    What I forgot to mention: The model is build from several solid-layers of CFRP with different orientations. Having only one orientation, there´s no such issue with negative values in the contour plot.
  14. MaddogMcCree

    Interpolation Issue?

    Hey there, I´m researching composite structures with Abaqus and I`ve written a script to evaluate failure criteria - i.e. efforts of the structure. This is done by accessing the odb-file and writing a new FieldOutput to it (Hashin- and Puck-Criterion). So far everything worked well. But...

Part and Inventory Search