Cantilevered Truss, Whats The Best Assembly 1

[YuleMsee]

Analysed the 4, deflections vary slightly, is there a better arrangement specifically for cantilevers?

 

[LittleWheels]

It mostly depends on the material. Connections for timber braces are generally better in compression. Steel bracing is generally better in tension to prevent buckling.

 

[BAretired]

What a question! Can't read the output, don't know the dimensions, don't know the loading, don't understand the pink tapering of members, don't know why the truss gets deeper, away from the two pinned supports at the left.

Altogether, a very bad presentation!

 

[YuleMsee]

@Littlewheels,
Going by that then my go to assembly is no. 3, to ensure biggest axial force is tensile. Element material is steel hollow sections as below

@BAretired
Well, I thought the photos would be clearer. First photo is moment (green) and axial (beige) element forces, second in pink is deflection
Its a 4m cantilever, steel R.H.S 60x40x3mm external elements and 40x40x3mm internal elements. Sloped top chord, roof pitch angle, gutter on the left. Assume the loading is 1 unit per node
The question is really on whether there are better truss types / element assembly methods that the ones tried above. I should remove those tables as they are just distracting from my question

 

[BAretired]

Thanks for the clarification, TuleMsee.

I don't see much difference between #2 and #3. The criteria for best assembly should be...which assembly results in the lowest aggregate cost. If chord members, RHS 60x40x3 have excess capacity, but Diagonal #2 needs something more than 40x40x3mm when in compression, then it should be rotated to put it in tension.

In any case, the difference in cost is minor, regardless of the choice.

 

[BAretired]

Maybe a more economical assembly could be found by varying the truss configuration (see below). Note that the bottom chord gets shorter as the force gets larger.