Tek-Tips is the largest IT community on the Internet today!

Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!

Register Log in
  • Congratulations cowski 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. lec235

    Eigenvalue buckling analysis hand calcs

    So the eigenvalue buckling analysis of an FE model isn't responding the way I expected it to based on some Euler buckling calcs. I want to check it via more detailed hand calcs (ie eigenvalue analysis and direct stiffness method) but have little to no idea about how to go about doing it. Are...
  2. lec235

    Buckling analysis

    verians, It took a bit of digging in the literature to find this when I had the same question, but the magnitude of the node displacements associated with a particular eigenvalue is meaningless. Basically, in *only* the case of a buckling analysis, ABAQUS assigns the node(s) with the highest...
  3. lec235

    Using discrete/analyically rigid elements with buckling analysis

    Its one of a series of models of various complexity of the same column configuration. I'm looking at possible simplifying assumptions and how that relates back to the buckling response of the actual structure. But I think you're on to something with the stiffness ratio idea. Thanks for the help!
  4. lec235

    Using discrete/analyically rigid elements with buckling analysis

    I think I've discovered a work around: use deformable parts meshed with a single beam element but specify the material to have young's/shear modulus of diamond.
  5. lec235

    Buckling of beam on elastic foundation

    Brian, That's what I'm finding is working. If the values in the initial eigenvalue analysis are large, you have to change the stiffness values a lot more than you expect. For example, in my model I started with k=1 and the mode 1 eigenvalue was 2.72747e05. Changing to k=100 gave a mode 1...
  6. lec235

    Using discrete/analyically rigid elements with buckling analysis

    Right. The links aren't supposed to buckle (hence why they're rigid). The deformation in the model is supposed to come from the springs that are connecting the links. So am I getting the error because the stiffness matrix for the links is essentially infinite? But wouldn't the fact that the...
  7. lec235

    Buckling of beam on elastic foundation

    Interesting thought. But would that be the case if the model is 2D and the mode shapes look right?
  8. lec235

    Using discrete/analyically rigid elements with buckling analysis

    Hi, Thanks for the response but yes I specified a unit vertical load on the top link.
  9. lec235

    Buckling of beam on elastic foundation

    I'm running into the same issue with my model. I'll let you know if I come up with something!
  10. lec235

    Using discrete/analyically rigid elements with buckling analysis

    So I'm trying to model a column with 4 rigid links for a buckling analysis. The overall structure is simply supported and there is also a linear spring at the middle joint. Each of the rigid links are connected to the one below via a rotational spring. I attached the model for reference...

Part and Inventory Search

Back
Top