Contact

1 tool in the Structures area.

Contact Stress

Hertz contact stresses for the contacts engineers meet in practice: sphere on sphere or flat, ball in a seat, cylinder on cylinder or flat, pin in a groove or bore, crossed cylinders, ball or roller on a bearing raceway, spur gear teeth at the pitch point, and any two bodies given by their principal radii and the angle between them. From the relative curvatures A and B the tool solves Hertz's elliptic-integral relations exactly (no chart interpolation) for the contact ellipse or strip, the maximum and mean pressure and the approach of the bodies, then evaluates the complete stress field below the surface, with optional sliding friction, by superposing the Boussinesq and Cerruti point-load solutions over the pressure: the maximum shear and octahedral shear stresses and their depths, the orthogonal shear that drives rolling-contact fatigue, the surface stresses and the tensile stress at the edge. Allowables from the compressive yield strength, the Brinell hardness, the ISO 76 permanent-set pressure and the AGMA contact stress numbers give margins of safety against first yield, brinelling, gross indentation, pitting and ring cracking. Saved materials fill the elastic constants and strengths.

2 worked examples reproduced, listed on the tool page.

Other Structures sections

Materials · Composites · Frames and Trusses · Beams · Loads and Dynamics · Joints · Stress and Strain · Stability · Plates and Shells · Thin-Walled Structures · Stress Concentrations · Fatigue · Damage Tolerance