Do STM struts need to be symmetric about strut axis???

[KootK]

When you're looking at a strut in a strut & tie model, does the strut need to be geometrically symmetric about the axis of the strut? Here's how I've come to wonder about this:

1) To solve a 2-D strut and tie problem, I developed a suitable truss model. The nodes in this truss model obviously define the axes of my struts & ties.

2) Tie layouts and bearing plates etc. define the geometries of my nodes.

3) When I connect all the dots from one node to the next, I end up with tapered struts with cross sections NOT quite symmetric about the axes that I defined in step #1.

Is this okay? In virtually all of the examples that I've reviewed, the struts end up looking pretty close to symmetrical -- at least graphically. That being said, it seems as though it would be a pretty big fluke for them to truly be symmetrical about the truss model axes.

I worry that, if the centroids of my struts are not coincident with the member axes of my truss model, there will be moments in the struts that haven't been accounted for.

Anybody know the answer to this? So far, I can't find anything that says a strut HAS to be concentric about it's longitudinal axes...

 

[petertor]

Good links and back to the original question, AHaddad1 had it right, don't over-think it: average stress, average section, and ignore imaginary del-P effects, S&T is just a conceptual.