Structural design knowledge: how steel in structural analysis?

     How steel in structural analysis?
     At present, the actual design of steel structures, structural analysis is usually linear elastic analysis, considering P-Δ, p-δ when conditions permit.
     Some recent finite element software can be considered part of the geometrically nonlinear elastic-plastic energy and steel. This provides the conditions for a more accurate analysis of the structure. Not all structures are required to use the software:
     The typical structure mechanics manual can check books like direct access to the internal force and deformation.
     Simple structure by hand calculations for analysis.
     Modeling complex structures only need to run the program and do the detailed structural analysis.