What is Hertzian contact theory?

Hertzian contact stress refers to the localized stresses that develop as two curved surfaces come in contact and deform slightly under the imposed loads. This amount of deformation is dependent on the modulus of elasticity of the material in contact.

What is the contact pressure between two bodies?

If the bodies are pressed with a force, say F, the contact, because of deformation, will not be in a single point but will be over a small area of the surface of each body. This surface is called the pressure surface. The curve that bounds the pressure surface is called the pressure contour.

What is Hertz equation?

where D is 3 4 { ( 1 − v 1 2 ) ( E 1 + ( 1 − v 2 2 ) / E 2 } and Wa is the load on the asperity. The subscripts refer to the two bodies. This is the Hertz equation and generally Ra may be written as a mutual radius of curvature where. (35) Ra1 and Ra2 are the radii of curvature in a particular plane.

What is contact stress analysis?

Contact stress analyses for spur and helical gears are performed between two gear teeth at different contact positions during rotation. Two examples of spur and helical gears are presented to investigate the respective variations of the contact stress in a pair of mating gears with the contact position.

What is the Hertzian contact theory?

The Hertzian Contact theory plays a major role in the fields of non-destructive-testing, mainly in the Impact Echo and the Local Acoustic Resonance Spectroscopy (LARS). 2,3 To compute the contact mechanics, Hertz made several assumptions: Firstly, the two interacting bodies are assumed to be of an elastic, isotropic and homogenous material.

What are the assumptions of Hertz contact mechanics?

To compute the contact mechanics, Hertz made several assumptions: Firstly, the two interacting bodies are assumed to be of an elastic, isotropic and homogenous material. Secondly, the surface is assumed to be perfectly smooth such that no shear stresses occur in the interacting surfaces.

Should the Hertzian contact stress be less than the yield stress?

ı think, the hertzian contact ( principal ) stresses should be less than the yield stress of material, otherwise some permanent damages will be occurred on the contact surface of two elastic bodies. Comments are closed.

What is the use of contact theory?

Hertz contact theory is a classical theory of contact mechanics and is a very useful tool for engineers and researchers. Even though the derivation of the theory is relatively difficult, the final solution is a set of simple analytical equations relating the properties of the system to the developed stress.