Structural Engineering & Statics
where the load goes
Concept

Slip — where it appears

Relative movement along an interface that was supposed to hold two parts together. A small amount of it turns full composite action into partial, and how much appears depends on the connection's stiffness rather than on its strength.

Named by 2 essays across one field — each of them below, with the objects they name alongside it.

36shearthe bars clamp, and do not carryasperity slope 54° · tan = 1.40clamping stress 2.50 N/mm² · resistance 3.50 N/mm²sliding without separating is not available to a rough crack

Shear across a crack that is already there

Every shear calculation in this collection starts from an uncracked solid — a principal stress, a shear flow, a diagonal tension. This one starts after the crack, on a plane with no tensile strength at all, and the coefficient it uses is not a coefficient of friction. It is the slope of the roughness.

internal-forces · shear friction 051015202530354000.20.40.60.81αLdegree of interaction96% at αL = 15.8one beamtwo beamsEI∞/EI₀ = 3.24 · the whole range is a factor of 3.24 in deflection

Half the studs, and most of the beam

Bonding two layers together quadruples the stiffness of the pair. A real connection is a row of studs that deform, so the layers slide a little and the beam sits between the two answers — but not halfway between, and the number that decides where is a single dimensionless group.

internal-forces · partial interaction

Named alongside it

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

Aggregate interlockAnchorageClamping forceCompatibilityComposite actionConstruction jointCorbelCrackDeflectionDilatancyDuctilityEquilibrium

All concepts