Load distribution in multiple rows & multiple column fasteners 1

[Mano1689]

I was working on the metallic plate with single shear lap joint of 9 fasteners(3rows x 3columns)and axial of P.
Anybody can suggest me how to calculate the load distribution for all 9 fasteners using classical approach and if possible kindly share the calculation manuals?

Thanks in advance..

 

[rb1957]

1/9 sounds pretty direct, yes?

you can easily set up a compliance model (Niu has an outline); you could put 1/3 of the load on each column, or use compliance to distribute, maybe 30:40:30, maybe 25:50:25.

whatever, the ultimate load capability will be with fasteners yielding, redistributing load, and ultimate load = 9*single fastener

Quando Omni Flunkus Moritati

 

[Mano1689]

rb1957..Thanks for your immediate response ..

Also i want to know among these 9 fasteners which will fail first under axial loading ? and Why?

Anybody can suggest to get these calculations in any books?

 

[rb1957]

"axial" = shear on the rivets ...

i'd suggest that compliance analysis would show that the middle fastener on the outer rows would fail first, assuming a point load applied in line with the middle fastener.

If a distributed load is applied then compliance analysis will show all of the outer fasteners (ie 6) are equally critical.

i'd suggest that in reality the joint allowable is 9*an individual fastener, and that the first one to fial might be any of them ... more likely to be an outer row by there could be issues with the middle row.

is this a student post ?

Quando Omni Flunkus Moritati

 

[Mano1689]

rb1957...Thanks for your response..I got it now..

Also suggest me some books for the fastener load distribution calculations..

 

[rb1957]

Niu (as I posted before)

Quando Omni Flunkus Moritati

 

[Sparweb]

How about Swift's papers on damage tolerance in pressurized aircraft?

How quickly the internet can forget things: where it once took seconds to find a PDF of that paper on the first page of Google hits, it's now buried.

Here's a link:

http://www.dtic.mil/dtic/tr/fulltext/u2/a225742.pdf

Various OEM manuals have joint efficiency calculations to shed some light on the stress in the fastened plates, too (probably all copied from an original work, like Lockheed stress memo's).


STF