Moment Connection at Splice??

[Wbruseski]

I would some opinions on whether or not a splice at a gable or mansard style roof should be considered a moment connection. This is for aluminum design of hollow self-mating sections (two C shaped stitched together) usually spiced with a gusset plate. Obviously at, say, the center of a flat span the splice is designed for the moment and shear at that point, but when the roof is gable or mansard (/\ or /--------\) is appropriate to assume that connection as a moment connection or hinge? Both work out in the model but of course with large differences of design forces. Is anything like this done in steel (more data)? Thanks for any input or reference.

 

[DaveAtkins]

I would draw a free body diagram of the gusset plate, with an equal and opposite moment on each side of the plate, where the members frame in. If you can use the fasteners (screws, I assume) on half of the gusset plate to get the moment into the gusset plate, and the fasteners on the other half of the gusset plate to get the moment back out of the gusset plate, then you have a moment splice. Don't forget to design the screws for any axial and shear forces that are present, also.