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Recent content by StevePAA

  1. StevePAA

    problem inserting pdfs into mathcad

    ok, I finally got back to this issue today. I tried and had the same problem when inserting a pdf into word so as expected it's definitely an adobe problem. As suggested, I performed a repair on acrobat and that fixed it. I don't really know what the issue was, but basically it was inserting...
  2. StevePAA

    stainless screws into aluminum (pt II)

    The NASA reference is one I found on the web- I don't have a link handy but you should be able to find it by searching for NASA stainless screw torque or similar. There is also another table on SST fasteners that is from ITT Harper and appears to be pirated by Fastenal. They are in close...
  3. StevePAA

    stainless screws into aluminum (pt II)

    for some background, this issue came about when checking dwgs for another company. An assy dwg has a SS 10-24 screw into mild steel with (for example) a 30 in-lb torque spec called out on the dwg. The same screw, same dwg, into alum had (for ex) 15 in-lb torque spec. I asked "why are you...
  4. StevePAA

    stainless screws into aluminum (pt II)

    Again, great graph and thanks for letting me use it- will save me some time.
  5. StevePAA

    stainless screws into aluminum (pt II)

    ok, I will edit here. Edit: What I found was that K was approximately .35 for #10 thru 5/16 sizes. This is slightly less than the ~.40 values if you back calculate from the NASA and ITT tables on SS fasteners. CoryPad: Did you prepare that graph for this post? if so, very nice. if you...
  6. StevePAA

    stainless screws into aluminum (pt II)

    thanks CoryPad, that is what I figured; since failure is outside the ~linear range, K will be higher than what's calculated from failure torque. since 18-8 has such a large spread between yield and ultimate I'm surprised that my failure K results are not further off than they seem to be at...
  7. StevePAA

    stainless screws into aluminum (pt II)

    a few yrs back (!) I started this thread on trying to find a K value for SS screws into aluminum. http://www.eng-tips.com/viewthread.cfm?qid=229169 The above thread is closed so I figure I'd start another. I tried to get the company to do a load cell study to measure clamping force vs...
  8. StevePAA

    problem inserting pdfs into mathcad

    this is a new problem that started once I removed adobe reader. I had both adobe acrobat 8 and reader 7 on this machine and removed reader. Before I could insert a pdf into mathcad with no problems using: insert, object, create from file, browse.... Now when I insert a pdf, the image doesn't...
  9. StevePAA

    cyclic symmetry in ALGOR static/linear analysis

    rybose: thanks for the tip on the book- i'll look for a copy.
  10. StevePAA

    cyclic symmetry in ALGOR static/linear analysis

    thanks. I eventually did talk to ALGOR and, like you said, this really isn't that difficult. The user's guide help on this topic just wasn't very clear to me. Searching for modeling symmetry gives some more info on it but not a cylindrical example. Set up a cylindrical coord system, apply that...
  11. StevePAA

    cyclic symmetry in ALGOR static/linear analysis

    hi, I have a cylindrical assy whose geometry repeats every 120* and would like to do the analysis on a 120* section instead of the entire assy. I have used symmetry on a 90* section which is easy, but I haven't used another interval like 120*. I know this is a very common analysis method but I...
  12. StevePAA

    allowable compressive stress under bolt head

    Thanks for the answers. Corus- the structural codes don't deal with this from what I've seen. Their definition of bearing stress is the material outboard of the bolt hole tearing away due to transverse loading (wrt to the bolt axis). What I am talking about is different- the contact...
  13. StevePAA

    allowable compressive stress under bolt head

    when doing an FEA that includes clamping forces for fasteners in a bolted joint, what is the allowable stress for the area under the bolt head that's subject to the clamping force? When you have a joint with large diameter fasteners, and allow for a ~20000 lbf clamp load you can see higher...
  14. StevePAA

    stress calcs for base metal of welded joint

    the shear at the hole where the rope/clip is attached was the final calc performed in the example :)
  15. StevePAA

    stress calcs for base metal of welded joint

    no, the metal below the weld is assumed thick and ignored. I believe ZCP has it right. The book ignores allowable stresses so I think the calcs need to be performed several ways (I did for my example) calcs for stress and FS in: the parent metal, the weld metal, and the bkt xsect at the...

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