Resolving Forces and Sizing Profiles in Structural Engineering

[Gunter1977]

TL;DR

Frame members

I'm with a home study structural engineering as an electrical engineer. The assignment that I am trying to do is calculating a frame to support a large pipe with a weight of 32,000 kN distributed across eight legs. ( so it on a job site) I've performed a detailed analysis of the forces using free-body diagrams and resolved the components for each member, as shown in the attached PDF. However,

I have encountered challenges in achieving consistent results across all members, particularly in balancing the sum of forces and moments. For instance, while I've determined the axial force in member M20 to be 5072 kN,

I'm struggling to achieve the same consistency for member M10.

Questions:
1. Method for Resolving Forces: How should I approach ensuring consistent results across all members? Are there specific methods or techniques I should consider to balance the forces and moments effectively?

2. Determining Profile Sizes: What factors should I consider when determining the sizes of profiles (beams)? Is it primarily based on considerations of tension, compression, or potential for buckling under load? I appreciate any insights or guidance on these issues. Thank you!

Thank you in advance,

 

[Baluncore]

1. Consider solving the loads as a matrix inversion, rather than sequentially, individually. Use space frame software.

2. Refine the design by changing, (preferably reducing), the sections based on tension, compression, and column stability (buckling).

What gives? Plastic design of steel structures, allows the material to bend when first installed. Do you want the pipe or the supporting frames to deform first? By designing the frames to deform, until the load is cradled in the structure, there will be significant savings in weight and cost.

 

[Lnewqban]

I believe that the free body diagram is very far from reality, as the lateral forces are non-existing, unless an external horizontal force is acting on the tank.

The only external forces acting on the support are the equally divided weight, acting solely in a vertical direction.
How the different members transfer those loads to the ground is a different matter.

Therefore, the represented four blue vectors seem to be incorrect.