Analyze an isolated steel column under axial and in-plane lateral loading using ASD or LRFD. Choose Wide Flange, Channel, MC Channel, or square, rectangular, or round HSS. The module provides finite-element analysis, member strength checks, and calculation reports.
Quick start
- Select the section, review material properties, and enter the column height in feet.
- Select ASD or LRFD and the Strong (X–X) or Weak (Y–Y) loading direction.
- Set top and bottom bending fixity to represent the actual supports.
- Choose Direct Analysis or Effective Length. Define bracing in both directions and assign K values where required.
- Specify top and bottom twist and warping restraints on the Torsion tab.
- Open Loads and Combinations, enter vertical and lateral loads, and review the enabled combinations.
- Choose Run Model. Review the Summary, Design Calculations, reactions, and diagrams before printing.
Supports, bracing, and torsion
Bending end fixity, intermediate lateral braces, and torsional restraints are separate inputs. The top support choices include translating supports and a free end; the bottom support can be pinned or fixed.
Use the X-X and Y-Y Bracing tabs to describe the actual restraint layout. Follow the explanatory labels: X-X bracing supports weak-axis buckling (Lcy), and Y-Y bracing supports strong-axis buckling (Lcx). Custom layouts define individual unbraced segments. Use K Values and K Overrides to review effective-length assumptions.
Check Braces provide torsional support only where the braces restrain twist. Select Free or Restrained separately for twist and warping at each end. Bending fixity does not automatically establish torsional restraint.
Analysis options
Direct Analysis uses second-order member analysis with notional loads and stiffness reductions. Effective Length uses the specified segment K factors and unreduced elastic stiffness. The program rejects Effective Length results when its checked second-order/first-order drift ratio exceeds 1.50.
First-order comparison, where available, disables geometric stiffness and P-Delta effects for comparison. Review the analysis method identified in the results. The Cb = 1 option sets the moment-gradient factor to unity; otherwise the applicable factor is calculated from the moment diagram. Shear deformation can be included with its checkbox.
This is an isolated, two-dimensional member model. A 3D view helps explain the section and restraints; it does not turn the analysis into a complete three-dimensional building-frame model.
Loads and combinations
Enter vertical loads as point loads at the top of the column. Enter lateral loads on the lateral-load tab at their actual locations. Follow the positive-load direction diagrams and the units shown in the editor; signed loads are retained. Review load categories, self-weight, and enabled combinations before running.
Results and reports
Review the governing combination and member checks in Summary and Design Calculations. Loading, V Diagram, M Diagram, Δ Diagram, and Reactions show the calculated response. Element Results and Element Forces provide the finite-element details; elements are numbered from bottom to top.
Review stability, compression, flexure, interaction, and shear results as applicable to the selected section. Correct invalid restraints, instability, or convergence errors before relying on the output. Use Report Options to select report details and rerun after changing engineering inputs.