F-02 — axial resistance

push or pull — every fiber feels the same.

σ = P ÷ A
axial capacity checker

push or pull. uniform stress everywhere.

Toggle tension vs compression, resize the section, and add bolt holes to see how net area changes the stress.

mode
bolt holes (tension only)
applied load
P (k)80
section
b (in)6.00
h (in)10.00
—
σ (ksi)
—
—
live equation
Ag = 6.00 × 10.00 = 60.00 in² σ = P / A = 80 / 60.00 = 1.33 ksi 2.7% of Fy = 50 ksi — well within capacity
σ = Uniform stress from axial load: σ = P/A
P = Tension or compression force along the axis
Ag = Full cross-sectional area without deductions
An = Area after deducting bolt holes
Fy = Stress at onset of permanent deformation
explained
Under pure axial load, every fiber of the cross-section carries the same stress. In tension, bolt holes reduce the effective area (net section). In compression, the full gross area works — but buckling may govern before the material yields.
key concepts
overview Axial stress σ = P/A is uniform; net area governs in tension

Axial stress σ = P/A is uniform across the section — every fiber carries the same load. In tension, the critical area is the net area (gross area minus bolt holes). In compression, the gross section is used — holes don't reduce compression capacity since the bolt fills the hole. Toggle tension/compression and add holes to see how each affects the design stress.

tension vs. compression Tension is uniform stress; limit is yielding or fracture

A member in pure tension is straightforward — stress is uniform across the section: σ = P / A. The limit is yielding (gross section) or fracture (net section through bolt holes). Tension members are efficient because every fiber of material works at the same stress. This is why cables, hangers, and brace rods are pure tension elements.

why compression is harder Buckling governs before material yields in slender columns

Compression is fundamentally different because of buckling. A short, stocky column fails by material yielding — just like tension, but pushing instead of pulling. A long, slender column buckles sideways before the material yields. The Euler buckling load Pcr = π²EI / L² depends on stiffness (EI) and length (L), not on material strength. This is why column design requires checking both yielding AND stability.