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

Static tests - when do you need to repeat them?

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

Static tests - when do you need to repeat them?

Old 8th Jun 2004, 22:02
  #1 (permalink)  
Thread Starter
Join Date: Aug 2001
Location: Greater Aldergrove
Age: 52
Posts: 851
Received 0 Likes on 0 Posts
Static tests - when do you need to repeat them?


With the static test approaching for the A380, I was wondering what the rules are regarding testing of different versions?

For example, once the A380 enters service, Airbus will probably try to engineer weight out of the structure, to enhance range, payload etc.

If they change some wing design detail, will the wing have to be retested?

Do Boeing have to retest the 777 wing with the changes introduced for the 772LR and 773ER?

Or for the A345/346, with a significantly bigger wing than the A343, did this structure have to go through a full destructive test?

Seems a rather expensive test, snapping a set of perfectly good wings! I'm sure the manufacturers don't like to overdo it!
NWSRG is offline  
Old 8th Jun 2004, 22:28
  #2 (permalink)  
Join Date: Feb 2000
Location: UK
Posts: 14,210
Received 48 Likes on 24 Posts
Absolutely, they fight tooth and nail to keep load testing to an absolute minimum - it's a very expensive and time consuming occupation.

In this day and age, static testing is not an absolute, it's part of a wider strength analysis, and is mostly used to validate a complex combination of finite element analysis and supporting manual calculations. It will also almost certainly have been done based upon company predictions of the long term weight increase that derivatives of that aircraft will need.

Where part of that structure is modified later in life, proof of that is mostly by analysis, based upon the records that exist of previous analysis and testing. There are two ways in which this can be done - one (the complicated and expensive way) is to re-stress and, if necessary, re-test everything. The other (the cheaper and easier way) is to prove that the modified bit of structure is "no worse than before" from all relevant strength, inertial, flexural and resonant viewpoints. This goes on all the time, not so much from a lightening viewpoint, but usually as in-service problems, areas prone to fatigue, the need to add a new box of electronics somewhere goes on constantly through the life of the aeroplane.

Genghis the Engineer is offline  
Old 12th Jun 2004, 07:48
  #3 (permalink)  
Join Date: Jun 2001
Location: Taiwan
Posts: 61
Likes: 0
Received 0 Likes on 0 Posts
The A380 is to use some composite ribs as part of their weight reduction program. Presumably other parts in the wing may extend the use of composite materials.

Is there enough known about composite ribs so that this is a natural extension of composites, or is this cutting edge use?

What other large acft use composite ribs, particularly on the main wing?

Would this change the structural stress testing program to that of a new, convensional wing?
IBTheseus 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

Copyright © 2024 MH Sub I, LLC dba Internet Brands. All rights reserved. Use of this site indicates your consent to the Terms of Use.