| Course contents :
| One distinguishes in mechanics the contacts from the type conforms intervening mainly in the traditional bearings and the contacts of the type non conforms with null surface of nominal contact. These last contacts either specific or linear occure in machine parts of first importance and great diffusion. They are the roller and ball bearings, gears, cam and roller which are used in fields as various as the heavy engineering, the car and the aerospace one. The theory of Hertz and its extension to the linear contact will be initially the object of a thorough talk (calculation of the deformations, contact pressures, stress field). Application of photoelasticity to the determination of the constraints of Hertz; Analyze modes of degradation of the hertzian contacts (chipping, pitting); False brinelling; Modification of the hertzian stress field by interposition of an oil film (EHD theory) - lubrication of ball bearings - lubrication of gears; Modification of the stress field by interposition of a foreign particle; Application of the theory of Hertz to the contact asperity/asperity of a surface of given characteristics; Comparison between mechanisms with contact in conformity and contact in non conformity. | |