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 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. JJ22mW

    Analysis/modeling methodology, aileron skins

    I've got a question regarding what the industry standard way is to apply air loads to flight control surfaces such as ailerons that have the typical sheetmetal skin/ ribs/spar design. On the project I'm working on, the loads are applied directly to the ribs/spars in the loads FEM, and nothing...
  2. JJ22mW

    sandwich panel

    I've always used 2D ortho for core. I don't think you'd be capturing any transverse compressive forces or stiffnesses with the CQUAD4's, considering they don't have two nodes in element Z direction that could move closer to eachother. And I wouldn't think that the deformations resulting from...
  3. JJ22mW

    fitting analysis

    For interior monument attachments (such as tie rod fittings), Boeing Doc. No. D6-55441 specifies to account for an additional load vector that is 10% of the axial load. This works out to a misalignment of about 5.7 degrees. Although some DER's want 7 degrees of misalignment. Just depends on...
  4. JJ22mW

    Analysis of Sandwich Panels

    The best way to get transverse load capability of a panel is by obtaining test data. Manufacturers like Gillfab post their panel strength data on their website.
  5. JJ22mW

    NAS6605-12 Bolts Bending Stress

    Depending on what the bolt is used for you may need to check for yielding under limit loads in addition to an ultimate loads analysis. You would of course using be using Fty as your bending stress allowable.
  6. JJ22mW

    TIe Rod in Compression

    I would just analyze the tie rod as an axial member in compression (using Niu, Bruhn, your company manual or whatever), I've never once had a DER be concerned with effects of end moments due to friction in the spherical bushings, because its most likely negligible. And if you have a positive...
  7. JJ22mW

    ESDU 80035

    Are you analyzing a Z, U, or T section beam? If so there's some empirical equations in the McCombs supplement that let you calculate allowable bending moments that are limited obviously by buckling of the outstanding flanges.
  8. JJ22mW

    ESDU 80035

    I've ran into this situation before as well. Even in Niu, the equation for calculating rotational restraint along the unloaded edge (Eq. 11.2.5) requres a variable 'Sv' (which is the same as your 'M' variable) to be known. The book says that the value of Sv is very difficult to determine and...
  9. JJ22mW

    Bypass stress

    I understand the term now, thanks guys.
  10. JJ22mW

    Bypass stress

    I've seen the term "bypass stress" used in threads regarding stresses around holes. What is bypass stress?
  11. JJ22mW

    Floor beam end fixity

    Thanks for the reply. Are end fixities typically modeled using torsional springs when the beam is modeled in the FEM using beam elements? If so, how is the spring constant value determined? Since the end moments will be a function of both the beam itself and the support structure, can you...
  12. JJ22mW

    Floor beam end fixity

    Typical applications are for 737, 747, etc. My company does executive interiors and many times we have to model floor structures to obtain x,y,z stiffnesses at certain locations of interior monument attachments. Floor structure is typically modeled using bar elements with pinned/fixed...
  13. JJ22mW

    Floor beam end fixity

    Hello, I have a question concerning end fixity of floor beams. Am I correct in interpreting end fixity as the ratio of the end rotation of the beam when subject to a unit moment (theta1 = L / 3EI) to the sum of theta1 and the rotation of the end support when subject to a unit moment (theta2 =...

Part and Inventory Search

Back
Top