Hertzian Contact Stresses Essay Example | Topics and Well Written Essays - 1750 words

Hertzian Contact Stresses - Essay Example Hertz identifies that the abutment of non-conforming forms was an example of stress accumulation that could be explicated liberated of the geometry and physics of stress field generated in the bodies. According to Heinrich Hertz," we can confine our attention to that part of each body which is very close to the point of contact, since here the stresses are extremely great compared with those occurring elsewhere, and consequently depends only to the smallest extent on the forces applied to other parts of the bodies." By circumscribing concentration to that fragment of the garb padlocked to the areas in contact with each other, the forces and wrench can be observed by evasion the slender cal arch of the surfaces of the two contacted bodies. The hertz theory is stimulated by two factors namely quadratic terms are used to delineate the geometry of general curved surface areas and the area of the body that have a curved surface mutilate as though they have elastic half spaces. From time t o time efforts are made to enhance hertz theory by considering higher order terms in the geometric elaboration of cylindrical or spherical profiles and by calculating the deformations of truly cylinder or spherical solids. Considering the hertz theory with respect to Marine engineering components, it has been observed that these components are designed to accommodate a defined life. Considering the case of Roll Bearings, which are used in ships, has approximately life of 65,000 hours and so accordingly this requires its replacement quite frequently during the tenure of the ship. The failure of these bearings is consorted with the inner raceway. The failures, which include the center radial, bearing of thrust bearing pair and radial drive end bearing, are also experienced. A very close examination depicts that the failure is the result of sub-surface fatigue. Once the cracks are instigated then it lead to grows and promulgate sub-surfaces. Following figure shows typical failure morphology of bearings This figure shows that Hertizan stresses plays important role in this failure process. On canvassing and implicating the Hertz theory in above scenario it is serene that shear forces are effectuated sub-surface and repose on plane close to