Structural Engineering & Statics
where the load goes
Concept

Bearing stress — where it appears

The compressive stress where one component presses on another over a contact area, rather than through a section. It is checked on an assumed area whenever the load spreads — under a base plate, at a bolt hole, at the toe of a masonry wall — and the area is usually the assumed part.

Named by 3 essays across 3 fields — each of them below, with the objects they name alongside it.

1200 kN214 kN of tiestruts at 20°0.5 huniform from here onGuyon: 0.25 P (1 − a/h) = 214 kN — the same number, from the same lever armbearing 20.0 N/mm² · once spread 5.7 N/mm²

The force that splits what it pushes on

A prestressing tendon delivers its whole force through a plate a fraction of the section deep. One depth further along the stress is uniform, and the spreading in between requires a transverse tension nobody applied — the force that splits end blocks, and the only number in the design that no equilibrium equation on the member can see.

internal-forces · anchorage zone T = 40 kN at 25°no pinnaclee = 0.503 moutside the middle thirdthe line stays in the stone · σ = 351 kPa at the toe

The weight that makes it safer

Every load in this collection makes a structure worse. A pinnacle does not. A masonry pier fails when the line of compression leaves the stonework, and adding weight at the top rotates that line back towards the vertical without adding anything the pier cannot carry — so the stone is not being strengthened, it is being aimed.

structures · buttress 00.10.20.30.40.500.20.40.60.81eccentricity ÷ thicknesscapacity ÷ squash loadthe kern66.7% at the kernno tension only1 − 2e/tslenderness 14.0adds e_a = 17.4 mmEuler is 10×above all of this

It does not buckle, it runs out of width

Every stability failure in this collection is a member that could have carried tension deciding to go sideways instead. Masonry cannot carry tension, and its failure under an eccentric load is not a bifurcation at all — the bearing area simply shrinks until it runs out. The capacity is exactly linear in the eccentricity, Euler's load is ten times anything allowed, and no material property appears until the very end.

stability · wall slenderness

Named alongside it

The objects these essays reach for when they reach for this one.

EquilibriumEccentricityFree bodyKernMasonryNo tensionSelf weightStabilityAnchorage zoneArchBucklingBursting

All concepts