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: *

  • Users: prost
  • Order by date
  1. prost

    One engineers perspective on global warming

    I don't know if this is of interest to anybody here--there was a "Climate Change Statement Review" published online, written by the Climate Change Statement Review Subcommittee of the American Physical Society (APS), dated Dec. 20, 2013 which outlines a number of questions that the committee...
  2. prost

    Stress Course for Liaison Engineers

    wktaylor: I am not the source of the documents, I am merely the messenger--I have no idea where the documents originated, so have no way of verifying what you say is right or wrong. I posted those two documents merely for the eng-tips.com forum readers' convenience. The location I previously...
  3. prost

    WARP3D

    Anybody out there use WARP3D before? I'd be interested in what you think of it--how much effort to get up and running? If you have experience with other FE software that has nonlinear fracture mechanics capabilities, how does it compare to those other software?
  4. prost

    Stress at integration points or at nodes ?

    What 'stress distribution' is assumed in the elements a priori? The only "distribution" that is assumed is the form of the displacement field. You start with pointwise equilibrium of the spatial derivatives of the stresses, which is not the same as assuming the stress distribution itself.
  5. prost

    Stress at integration points or at nodes ?

    If I am indeed calculating strains/stresses when I solve the FE equations, then shouldn't I be able to directly extract stress as say Node 1 (or some other points) without any more work? I can do this with the displacements--the "u" in Ku=f is my solution; therefore (if I used isoparametric...
  6. prost

    Stress at integration points or at nodes ?

    I still don't think you need to know anything about the stresses to compute the displacements. You are enforcing equilibrium of stresses, but only in a global sense through the integrals of the principle of virtual work, which is one reason why they call the principal of virtual work "the weak...
  7. prost

    Stress at integration points or at nodes ?

    Thanks feajob. This reference I missed. Was this the source of the "superconvergent patch recovery" technique I've heard about? I've seen a few papers recently that discussed proofs for particular cases.
  8. prost

    Qantas 747 oxygen tank rupture

    Even if the water is shallow, you can have trouble finding it--a heli went into Lake of the Ozarks, in Missouri in 2008 (a man made lake whose waters are 'murky'); they knew exactly where it went in, because there were witnesses nearby. Took authorities 2 days to find it. I didn't hear...
  9. prost

    What Ever Happened to RAPIDC?

    Try again. Sorry, I mistakenly deleted it. www.apesolutions.com/spd/public Let me know in this forum if you have a problem with any of the files (perhaps there was a problem transferring files from my computer to the download site; if so, I can try to recopy the file(s) and see if that...
  10. prost

    Stress at integration points or at nodes ?

    Incidentally, I doubt very much my use of 1D elements to illustrate that the stresses aren't actually computed directly until after the solution (the displacements) are found was 'specious'--the derivation of 1D, 2D and 3D finite element matrices have many many similarities that illustrate the...
  11. prost

    Stress at integration points or at nodes ?

    My question had nothing whatsoever to do with the difference between measured and calculated stresses. My question had to do with the general principle of assuming calculated stresses are more accurate at the integration points than they are at the nodal points. My assumption was that was a...
  12. prost

    Stress Course for Liaison Engineers

    The location of the two documents--the original training course and the answer key, has apparently moved. You can get the following two documents: Stress_Course_for_Liasion_Engineers.pdf Aircraft_Structures_for_Engineers___Solutions.pdf now at following website...
  13. prost

    Stress at integration points or at nodes ?

    Apparently, we are all reading different finite element textbooks, each with its own set of messages that the authors mean to convey. Therefore, we each have a different knowledge basis for comparing what we think we know about things like FE and what others seem to know. For instance, I learned...
  14. prost

    Pigeon droppings failure

    Anybody heard this one? Airplane on tarmac, landing gear collapses. Failure from a pit caused by guard urinating on said landing gear.
  15. prost

    Stress at integration points or at nodes ?

    After more research, I am still stumped. Though I do have a few papers whose authors make the same claim about 'stresses at the integration points being more accurate than at the edges' matter of factly. So I have some more digging to do to figure out why. One person I know uses ANSYS I think...
  16. prost

    Stress at integration points or at nodes ?

    Apparently others here think that there are other ways to compute stresses than the obvious one (using spatial derivatives of the solution vector), so I'll do some more research to see what others are doing. I can't imagine how you can use the stiffness matrix and the solution vector to compute...
  17. prost

    Stress at integration points or at nodes ?

    pja-thanks for the reference. I have only 3rd edition of Cook, Concepts and Applications of Finite Element Analysis, available. Could you possibly supply the Chapter and section number (and/or title) to help me zero in on the correct section, since almost undoubtedly the pages are different from...
  18. prost

    Stress at integration points or at nodes ?

    Not to sound overly critical, but have you ever constructed by hand a 'finite element'? It appears not, since you have stated that stresses and strains are needed. To illustrate, I think I don't lose any generality by describing how the finite element matrix is constructed in 1D, for rods. We...
  19. prost

    Plate with hole under uniaxial tension

    rb1957 Are you referring to NACA TN 2073? Stress and Strain Concentration at a Circular Hole in an Infinite Plate, by Elbridge Stowell? Published in 1950.
  20. prost

    Stress at integration points or at nodes ?

    What is the basis for the statement "stresses are implicitly calculated from the solution to Ku=f"? In a linear solutions, where are stresses (or strains for that matter) in "K," "u" or "f"? No, stresses are calculated AFTER you compute the displacement vector "u", by computing, as you know, the...

Part and Inventory Search

Back
Top