Embedment pressure

Embedment, pressure
profile proj. Area A = d · s
ρ _max  = maximum surface pressure
ρ _min  = minimum surface pressure

Multi-level connection
proj. Area A = d * 2 * s ₁ ; if s ₂   > 2 s ₁

As bearing pressure , Lochleibungspressung or Leibungsspannung occurring is surface pressure between the periphery of the shank of screws , bolts and rivets and the bearing stress , respectively. The symbol for the bearing pressure is . The historical spelling of the reveal is less common today. ${\displaystyle \sigma _{l}}$

The embedment is an important static parameter for the calculation of material thicknesses depending on the load.

calculation

The bearing pressure results from the force  F that the rivet or screw is supposed to transmit and the contact area between the rivet or screw shaft and the reveal. Since the transferring cylinder surface is semicircular and the distribution of forces on the semicircle is irregular, an averaged value for σ _{l is} assumed for the calculation and the cylinder surface is projected into the plane to simplify matters.

This results in the rough formula:

${\displaystyle \sigma _{l}={\frac {F}{d\cdot s\cdot n}}}$

F = force to be transmitted d = diameter of the rivet or bolt struck = hole diameter s = smallest sum of all sheet metal thicknesses in one direction of force n = number of rivets or bolts

Around 1900 it was recommended in the specialist literature to limit the compressive stress in the reveal of riveted iron structures to 140 N / mm² in order to avoid exceeding the yield point of the material.

Footnotes

1. ^ A. Kröner: Handbuch der Architektur, Volume 3, Part 1 , S. 144ff, 1891
2. ↑ A. Kröner: Handbuch der Architektur, Volume 3, Part 1 , P. 148, 1891