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stress analysis

  1. proppastie

    Spar Failure

    This is real...Background: Phil in Ireland is building a Carbon Dragon and testing his spar had a failure. http://www.ihpa.ie/carbon-dragon/index.php/forum/carbon-dragon/809-progress-on-phil-lardner-s-all-carbon-cd?start=60 He has decided to splice the center with Aluminum. This splice is...
  2. proppastie

    Peery Question

    I am pretty sure the calculations/assumptions I made on the first case shown in the attached spread sheet is wrong but I do not know what/how to get the right answer. No example is shown. The assumption I have made is that the K of the chart incorporates the terms Rb^2+Rs^2=1 however the...
  3. proppastie

    Aluminum Built UP Spar Question

    For manufacturing and weight considerations, (I do not want to bend .04 2024-t3) I am considering a built up spar c-channel web with separate riveted flanges as shown in the attached file. Shown is the compression top cap, web, flange, and flat caps. Rivets are not shown. Would anyone like...
  4. proppastie

    FEA Rivet Stress

    It is my belief that soon affordable FEA tools will be in the hands of us novice designers through the use of student licenses and at some point reasonable priced copies. Perhaps those of you that use the 40K seats of ANSI or whatever might a have quick answer to a basic question. I am trying...
  5. proppastie

    Wilford EAA Sport Aviation Articles for Spreadsheets

    Are there EAA Sport Aviation Articles that flesh out or clarify the EAA spreadsheets by Wilford? I could not find them here. If they add something it would be nice to have them.
  6. proppastie

    FEA vs Traditional Conservative analysis

    Those of you that do FEA, has there been any comparison to weight saving vs conservative approaches. For example, we conservatively say the caps handle the bending, the web handles the shear, the skin handles the torque. We design for Compression on the caps. (please correct this if it is...
  7. proppastie

    BRUHN C10.18 and EAA Spar Design

    Looking at Bruhn section C10.18 Fig. C10.20 for Web =.025, h/t=388. Willford Spar Design Spread sheet cell E72. Willford has this number at -4654 and the Bruhn extrapolation should be lets say +4654. That sign makes a difference in the result. Any comments from the Stress Engineers on...
  8. proppastie


    Aircraft Structural Design Manual Vol 1 - McDonnell-Douglas (1982) WW The price can not be beat (free on line). I mounted this thread in case there are detail questions about the content. You can also try a Google search and probably will be able to download it for free.
  9. G

    Stress Analysis of In-Plane, Shear-Loaded, Adhesively Bonded Composite Joints and As

    Here you go, having problems sleeping? Just start reading this and you'll experience a total eyelid blackout. Yes it's a FAA publication 36 pages and can be downloaded here: http://www.niar.wichita.edu/agate/Documents/Materials/DOT-FAA-AR-01-07.pdf Stress Analysis of In-Plane, Shear-Loaded...
  10. proppastie

    Using Autocad V14 Region data and Solids data for stress analysis

    After reading 10 pages of threads with the key-word “stress” I do not feel I belong in the same room. That being said I am doing a feasibility/design study of converting an existing design to aluminum stressed skin design. I am using the Autocad region data and solid properties data. I am not...
  11. A

    Stress Analysis, Structural Design

    Greetings to everyone: I provide engineering assistance in the following areas: Structural Design of aircraft parts. Stress Analysis of aircraft parts. Below are examples of projects which have successfully been accomplished online. Aircrafts in those projects have already been constructed...