Back to back double angles - EC3

[LYO]

Hi there,

Good day.

Need your help for this back to back double angle, gapped at 8mm.

BS EN 1993-1 : 6.4.4 .....the maximum spacing between interconnections for back to back angle shall be 15xminimum radius of gyration.

If this requirement is not there (spacing of connector > 15 x Imin), can we design these double angles as individual angle by assuming equal load distribution? The capacity of this element will be a total of 2 individual angle?

Many many thanks

 

[KootK]

can we design these double angles as individual angle by assuming equal load distribution? The capacity of this element will be a total of 2 individual angle?

You mean to do this by assuming the angle lengths to be the full length of the member, right? If so, you can do that but it may be unnecessarily conservative. Here's another approach:

1) Find the capacity of both angles combined and assumed to be behaving compositely.

2) Find the capacity of one angle of a length equal to the connector spacing and double it.

Use the smaller of #1 and #2 as your capacity. Since your connectors facilitate the composite behavior of #1, I'd want to have connectors at 0.25 x L at minimum.

I like to debate structural engineering theory -- a lot. If I challenge you on something, know that I'm doing so because I respect your opinion enough to either change it or adopt it.