TablesC-C design for stability
General stability requirements
PDF page 402 · AISC 360-22
| Basic Requirement in Section C1 | Provision in Direct Analysis Method (DM) | Provision in Effective Length Method (ELM) | |
|---|---|---|---|
| (1) Consider all deformations | C2.1(a). Consider all deformations | Same as DM (by reference to C2.1) | |
| (2) Consider second-order effects (both P-∆ and P-δ) | C2.1(b). Consider second-order effects (P-∆ and P-δ)[b] | Same as DM (by reference to C2.1) | |
| (3) Consider geometric imperfections This includes joint- position imperfections[a] (which affect structure response) and member imperfections (which affect structure response and member strength). | Effect of system imperfections on structure response | C2.2a. Direct modeling or C2.2b. Notional loads | Same as DM, second option only (by reference to C2.2b) |
| Effect of member imperfections on structure response | Included in the stiffness reduction specified in C2.3 | All these effects are considered by using Lc = KL from a sidesway buckling analysis in the member strength check. Note that the differences between DM and ELM are as follows: • DM uses reduced stiffness in the analysis and Lc = L in the member strength check. • ELM uses full stiffness in the analysis and Lc = KL from sidesway buckling analysis in the member strength check. | |
| Effect of member imperfections on member strength | Included in member strength formulas, with Lc = L | ||
| (4) Consider stiffness reduction due to inelasticity This affects structure response and member strength. | Effect of stiffness reduction on structure response | Included in the stiffness reduction specified in C2.3 | |
| Effect of stiffness reduction on member strength | Included in member strength formulas, with Lc = L | ||
| (5) Consider uncertainty in strength and stiffness This affects structure response and member strength. | Effect of stiffness/ strength uncertainty on structure response | Included in the stiffness reduction specified in C2.3 | |
| Effect of stiffness/ strength uncertainty on member strength | Included in member strength formulas, with Lc = L | ||