Measure load-bearing capacity in SU

[endlessfix]

To answer the original question:

Bending a beam like having a force at some point

If you are just trying to model an approximate example of beam behavior under load the extension FredoScale does bending and twisting. If you are looking for accurate stress analysis or bending moment calcs of a given object or material I am not aware of any plugins for SU that do true FEA, I wish there were.