How to Create a Flow-Only Part Assembly Sketch

Hello

I'm trying to figure out how to create a sketch of assembling a piece in a single flow.

I have studs connected to a joist that is flow only (studs put in place by the bolt utility). 

Except that in the flow sheets of these bars, the studs are not displayed.

When I try to create an assembly sheet, tekla rejects me...  

I know that I can go through other methods, using macro studs or fused parts that will allow to have the studs as a part and not bolts. But it would make my model considerably heavier.

If anyone has a solution? 

Thank you 

Valentine