Shear connectors - full composite action

[slickdeals]

How do you determine the number of connectors or size of weld to ensure full composite action between 2 connected members?

Say.... 2 nested decks or WT + Wide flange etc. How would the number of connectors affect the deflection?

 

[WillisV]

VQ/I. With full VQ/I attachment two members act as a composite section (assuming the two members are the same length). By definition of full composite action the deflection is calculated based on the moment of inertia of the total built up section.

 

[slickdeals]

@Willis:
What do you mean by full VQ/I? Isn't it still based on the actual loads or is this a higher V based on member capacity?

 

[msquared48]

The number, size and spacing of connectors provided is directly related to the level of the composite S and I developed, hence the variable VQ/I based on the number of connectors.

Mike McCann
MMC Engineering
Motto: KISS
Motivation: Don't ask

 

[WillisV]

@slick - you can back-out the "V" corresponding to the number and strength of connectors to see at what point your connection no longer provides the required composite action; alternately, you could determine the number of connectors based on a "V" corresponding to the failure load of the composite system if you want to make sure it stays composite to failure (e.g. the V corresponding to flexural failure of the combined system). Generally though, you know the max load, so just use that to determine V and determine anchors from there.

 

[ash060]

If I was going to nest decks I would just use double the I. The metal deck is so thin that you probably won't get a huge bang for your buck by making them composite. It would certainly be cheaper to use a deeper deck.