Distance of the bolt axis

Symbol ssym
Unit mm
Attribute-ID vdi_2230_distance_of_the_bolt_axis
Numeric ID 12120
Value Type PMTechValue

The distance of the bolt axis ssym  from the axis of the imaginary laterally symmetrical deformation body 0 defines the eccentric clamping of the bolted joint.

0 Axis of the imaginary laterally symmetrical deformation body
S Bolt axis
FS Bolt load
FA Axial load
a Distance of the axial force from the axis of the imaginary laterally symmetrical deformation body
ssym Distance of the bolt axis from the axis of the imaginary laterally symmetrical deformation body
u Edge distance of the opening point U from 0
U Opening point
v Distance of the edge bearing point V from 0
V Edge bearing point
Loading case/ variant Tensile working load Compressive working load
I II III IV V VI
Dimensional ratios position of a and ssym at 0 position of a and ssym at 0
on same side different sides on same side different sides
a≥​ssym a<ssym a≥​ssym a<ssym
Sign ssym + + - + + -
u + - + - - -
Explanations
  • The distance a of the substitutional line of action of the axial working load is always positive.
  • Point U always lies at the outermost location of that side of the interface which is at risk of opening, and consequently point V lies at the outermost location of the other side.
  • The distance v is always positive.

Note: Cases V and VI can only lead to opening in exceptional instances. Case IV is only illustrated for the sake of completeness; opening cannot be expected.

Table from: VDI 2230 Part 1, VDI Verlag Düsseldorf, 2015, p. 69, "Table 4. Sign rules."