bolted joint.

[kotawsu]

what would happen if all the bolts are rigid in a joint. would all the bolt carry the same load? and what about deflection?

 

[SlideRuleEra]

In general terms, what you are describing is a slip-critical joint - the bolts are so tight that the members are kept from moving (under load) by friction. However assuming that each bolt carries the same load is probably not totally accurate. Here is a discussion of one aspect...

http://www.aisc.org/MSCTemplate.cfm...tomSource/Faq/SteelInterchange.cfm&FaqID=2069

Again in general terms, deflection of a beam could be less since the joint becomes more "fixed" than a traditional "simple" support. For reference, look in the AISC manual "Beam Diagrams and Formulas" and compare diagram 15 with diagram 1. This is just typical example, things could be very different depending on the exact conditions.

http://www.SlideRuleEra.net

 

[desertfox]

Hi kotawsu

The bolts may theoretically carry equal loads ie:- BY DESIGN but in practice this is not usually the case.
Load distribution in a pattern of bolts depends on how the bolts are loaded.
Take say a angled bracket fastened vetically to the wall by a vertical line of bolts, at the top of the bracket,lets say
theres a horizontal ledge with a vertical load trying to prise the bracket off the wall. The load distribution in the vertical line of bolts will not be equal ie:- the bolt near the top of the bracket will see the most load while that furthest away from the top of the bracket will see the least.
Can you elaborate more on the joint you have?

regards desertfox

 

[Qshake]

If you are concerned about the conditions of fixity vs. the beam or element displacements/rotations you can read this directly in the Steel Structures Design and Behavior by Salmon and Johnson.

Regards,
Qshake

Eng-Tips Forums:Real Solutions for Real Problems Really Quick.

 

[MotorCity]

It is theoretically IMPOSSIBLE for multiple bolts in a connection to share a load equally (except at plastic failure). From basic statics, it is also indeterminate.

If you anticipate movement and design for movement at a connection, it is a slip critical connection as SlideRuleEra described above. However, there are a limited number of cases that these connections are practical. Cases include structures with load reversals such as bridges or expansion joints in buildings.

Good luck.