INTELLIGENT WORK FORUMS
FOR ENGINEERING PROFESSIONALS

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Jobs

Landing gear attach point composite load

Landing gear attach point composite load

(OP)
Hi

I'm searching the best way to attach a fixed main landing gear for an homebuilt aircraft of 1200lbs gross (planned.) The landing gear leg will be a spring type or a rubber donut type. But for the fixture onto a composite wing section :

1- A bracket directly fastened on the spar web
2- The leg having a T shape at top that attach to: spar and front plate in D-cell, as extra wing rib.

And in both case, is the spar cap must be adjusted to the extra shock load at landing Or just by extra ply for the web.. ? Or the load reaction is better spread in 2 supporting member as on the picture.. ?

Many thanks

RE: Landing gear attach point composite load

Is more oxygen better than less oxygen? Yes in that sense I'd think more support points are better to distribute the load, obvious.

But at what cost are you making that extra oxygen or spreading the load? That is what you really need to focus on in my humble opinion.

Aerospace Stress Analysis and FEA Courses
http://www.stressebook.com
Stressing Stresslessly!

RE: Landing gear attach point composite load

as i understand your sketches, the choice is between cantilevering the LG directly off the spar (LH fig) or building up a structure around the LG pintle so that the load is distributed into the spar (RH fig).

you have to remember the class of plane being worked on (kit built, 1200 lbs) ... so simple crude structures can work, and expensive, complex structures may cost the plane out of business.

If you do go the simple concentrated load path, build a heavy fitting to take the load. Remember all the "odd" direction loads, so that your single point cantilever can react all the loads from the LG. I suspect your fitting will need a sizeable socket to pick up the pintle well.

remember too sometimes you have stiffness constraints ... something may be statically adequate, but too flexible.

another day in paradise, or is paradise one day closer ?

RE: Landing gear attach point composite load

(OP)
Hi
Thanks for reply rb1957. So by going with an heavy plate just like this one :


That could spread the load accordingly. .?

As I plan for an I beam, I might be in need for an extra bracket. But in both case, if a dual mount point is used, with an hard landing, is the spar will might get delamination... If that's the case, a single point will be ok, as I will have to scrap the whole wing anyway.

RE: Landing gear attach point composite load

looks ok for a concept ...

another day in paradise, or is paradise one day closer ?

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members!


Resources


Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close