Nonlinear structural analysis uses a great number of terms to define exactly what is “nonlinear” in the model. Recently as part of code committee work for both AISC and AISI I developed a table summarizing terms in current use. This work is shared here so that others might take advantage of this effort and better understand the terms used for nonlinear analysis of civil (steel) structures – particularly buildings.
| “Eurocode” | MASTAN | General | AISC & AISC TC’s | Seismic (ASCE 7/41, Other) |
Abbreviation (Eurocode Style) |
| Linear Analysis | 1stOrder Elastic | (Linear) Static | First-order | Equivalent Lateral Force | LA |
| Dynamic, Time History, Response Spectrum | |||||
| Linear Buckling Analysis | Elastic Critical Load | Buckling, or Eigenbuckling | (Sidesway) (frame) (elastic) buckling analysis | LBA | |
| Natural Period or Vibration Mode | |||||
| Material Nonlinear Analysis | 1stOrder Inelastic | Plastic | Plastic Hinge Methods, Appendix 1 | Nonlinear Static, (Pushover) w/o P-D | MNA |
| Geometric Nonlinear Analysis | 2ndOrder Elastic | Path-following | Second-order, Direct Analysis (w/ Notional Loads) |
GNA | |
| Geometric Nonlinear Analysis on Imperfect Structure | P-D: Direct Analysis
P-D and P-d: DMMI |
GNIA | |||
| Geometric and Material Nonlinear Analysis | 2ndOrder Inelastic | Nonlinear Static, (Pushover) Analysis | GMNA | ||
| Nonlinear Dynamic (Response History) | |||||
| Geometric and Material Nonlinear Analysis with Imperfections(1) | Collapse analysis | Appendix 1 | GMNIA(1) |