# Calculation of contact stress

Hertzian stress and subsurface stresses are calculated for point or line contact. The radii of curvature for two bodies can be given in two planes. An angle between the planes for body 1 and body 2 can be defined. The stresses for both bodies are the same for equal materials, for different materials they can differ. A demo version for windows is available here, it has the same inputs but provides additional graphics.
These online calculations are provided free of charge by MESYS AG. The software is tested and no errors are known, but there is no warranty for the correctness of the results and for the availability of the calculations. The usage is at own risk.

 Body 1 BallCylinderEllipsoid First radius body 1 r11 mm Body 2 BallCylinderEllipsoidPlane First radius body 2 r21 mm Normal force Fn N Youngs modulus body 1 E1 MPa Youngs modulus body 2 E2 MPa Poisson number body 1 ν1 Poisson number body 2 ν2 Angle between axes α °
 First radius body 1 r₁₁ 5 mm Second radius body 1 r₁₂ 5 mm First radius body 2 r₂₁ 5 mm Second radius body 2 r₂₂ 5 mm Angle between planes for radii α 0 ° Youngs modulus body 1 E₁ 210000 MPa Poisson number body 1 υ₁ 0.3 Youngs modulus body 2 E₂ 210000 MPa Poisson number body 2 υ₂ 0.3 Normal force Fn 100 N Hertzian stress pH 3454.4 MPa Major half axis of contact ellipse a 0.1176 mm Minor half axis of contact ellipse b 0.1176 mm Approach of both bodies δ 0.0055 mm Maximal shear stress body 1 τMax₁ 1070.93 MPa Depth for max. shear stress body 1 z(τMax₁) 0.0565 mm Maximal octahedral shear stress body 1 τOctMax₁ 1009.69 MPa Maximal shear stress body 2 τMax₂ 1070.93 MPa Depth for max. shear stress body 2 z(τMax₂) 0.0565 mm Maximal octahedral shear stress body 2 τOctMax₂ 1009.69 MPa Maximal orthogonal shear stress τyz 738.86 MPa Depth for max. orthogonal shear stress z(τyz) 0.0413 mm