Go Back  PPRuNe Forums > Flight Deck Forums > Tech Log
Reload this Page >

Fired engineer calls 787's plastic fuselage unsafe

Tech Log The very best in practical technical discussion on the web

Fired engineer calls 787's plastic fuselage unsafe

Old 23rd Jan 2008, 15:32
  #81 (permalink)  
 
Join Date: Dec 2004
Location: swindon
Age: 40
Posts: 88
Blip,

I agree with you that energy cannot be absorbed without distortion of the structure.

Race cars absorb energy based on known failure rate of the structure. The structure is based on layers of composite that “commit suicide” and disintegrate to manage the force of impact.



What I’m confused about is the assumption that the composite failure strength is less than that of “absolute Failure” of Aluminium (after buckling and distortion). In my (limited) experience on GA types I was always taught to make sure the composite failure rate was equal or greater than that of the “Absolute failure” of traditional material.

I have tried to demonstrate this in the following diagram.




Impact 1 – Composite structure Integrity remains intact; Aluminium Structure is deformed but some strength remains.

Impact 2 – Both Composite and Aluminium structure fail – no integral strength remains.

So are we to assume the Boeing intends for the Composite structure failure to be LESS that the absolute failure of alternatives?

Smala01
smala01 is offline  

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Thread Tools
Search this Thread

Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service - Do Not Sell My Personal Information

Copyright © 2018 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.