Beam/Truss analysis

Hi there,

I'm doing a project about transmission lines and I need a little help about the analysis...how I know which section is the best for this structure ? Does the Creo has any tool about it ? I was considering using shape factors...
And how I know if the beams will resist ? I thought about Von Mises tension but I see no connection there...

You can see the model below...

Thanks,
Best regards..