Stability

4 tools in the Structures area.

Column Stability

Compression strengths of columns can be predicted using theoretical elastic solutions for slender, symmetrical and centroidally-loaded columns. For short or eccentrically loaded columns, corrections need to be made using one of several methods:

Column Buckling Tables

Critical stress and load of a centrally loaded column about both axes for the six classical end conditions, with the theoretical effective-length factor K of Timoshenko and Gere and the recommended design value of AISC 360-16 Table C-A-7.1 side by side, or an entered K. The Euler stress, the Johnson parabola (transition at F_y/2), the AISC 360-16 Section E3 column curve (0.658^(F_y/F_e) F_y and 0.877 F_e with φ_c = 0.90 and Ω_c = 1.67) and the tangent-modulus (Engesser) stress with a Ramberg–Osgood E_t are evaluated at the governing slenderness KL/r, tabulated against KL/r or length in ten steps and drawn with the applied point; an entered load gives the LRFD and ASD demand-to-capacity ratios. The section is typed (A with I_x, I_y or r_x, r_y) or filled from a saved section, the material from a saved MIL-HDBK-5J material. The default case is Example 13.1 of Hibbeler's Mechanics of Materials (a pinned 12-ft A-36 W8x31: Euler 512 kip, 56.1 ksi above yield, so 329 kip governs).

1 worked example reproduced, listed on the tool page.

Beam Column Strength

Analyzes beam-columns subjected to combined axial compression and lateral loading using the Gittleman Method. This tool handles columns composed of multiple segments, where each segment has constant properties (E, I) but different segments may have different properties. The analysis includes multiple concentrated and distributed lateral loads, applied end moments, and initial eccentricity, accounting for axial load magnification effects on bending moments through second-order P-delta analysis.

Plate Buckling

Analyses a web buckling capability of an orthotropic or isotropic plate given a general loading N_xx, N_yy, N_xy. Uses both buckling coefficients with interaction equations and the Rayleigh-Ritz method.

3 worked examples reproduced, listed on the tool page.

Other Structures sections

Materials · Composites · Frames and Trusses · Beams · Loads and Dynamics · Joints · Stress and Strain · Plates and Shells · Thin-Walled Structures · Contact · Stress Concentrations · Fatigue · Damage Tolerance