Prying action in welded connections

[Ipetu]

p9-10 of AISC Steel Construction Manual 13Ed. covers determination of angle thickness to eliminate prying action when angle is bolted down. How does one determine corresponding thickness when angle is welded down? Any references out there?

 

[ishvaaag]

You can see in Pilkey's way of solving for the required throat of welds that you determine first the stresses fx fy and fz in 3 orhogonal directions, then make a square root of the sum of their squares to compare to some fa allowable design criteria. Hence there the usual determination of the stresses is elastic when using this method that akcnowledges the actual geometry and assume the usual variations of stresses along the weld lines. You have then acknowledge the moment effect but if you want, not any nonlinear stress effect due to closer proximity to one tip than another; it must be surmised that such method being for in the end a limit strength check (be it that we may formulate in allowable stresses terms) acknowledges the fact of the procedure involving the implied redistribution of stresses to a linear statement of the same is safe.

Prying action in bolts can be thought as well be linear, merely an acknowledgement of lever action between bolts and tips when the pull is applied to the end of the lever arm. You can have the same evaluation of the total forces in prying action for a pot weld substituting some lost bolt that had prying action. Yet it wouldn't differ of Pilkey's method, you would be determining just the fx fy fz in the line pot weld.

 

[desertfox]

Hi Ipetu

Have a look at this site:-

http://www.roymech.co.uk/Useful_Tables/Form/Weld_strength.html

desertfox

 

[ash060]

You don't get prying action if you are welding. The first line under Prying Action in the Steel Manual says in bolted construction only.

 

[slickdeals]

You will have to determine the angle thickness assuming that the load is applied at the centerline and the resistance is offered by welding along the leg (if that's the case).
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Prying action only increases bolt tension loads on a flexible angle. But your angle thickness will need to be sized regardless of welding or bolting.