EHL line contact — film thickness

Central film thickness of an elastohydrodynamic line contact from the Moes dimensionless load/lubrication groups, with contact half-width and Hertzian pressures.

✓ validated against legacyoriginal: /calculators/e12_4.htm
Central film thickness, h_c1.25 µm
Contact half-width, b0.41 mm
Mean pressure, pₘ1.23 GPa
Max pressure, p₀1.56 GPa

Dimensionless groups

Dimensionless film, H6.92
Moes L16.82
Moes M23.98
Reduced modulus, E*230.8 GPa
Reduced radius, R*15 mm

Method & references

  • Moes / Dowson–Higginson dimensionless film-thickness relations for EHL line contacts.
  • A radius of 0 represents a flat surface.

The computation is a literal port of the original client-side JavaScript from /calculators/e12_4.htm. Results are verified equal to the original by an automated golden-master test. No formula has been re-derived or “improved”.