Кваліфікаційні роботи здобувачів вищої освіти кафедри кафедри авіаційного транспорту

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Browsing Кваліфікаційні роботи здобувачів вищої освіти кафедри кафедри авіаційного транспорту by Author "Kyryk, Liliia"

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    Methods of testing on wear at high contact pressure
    (National Aviation University, 2022-11) Kyryk, Liliia; Кирик, Лілія
    As our technological civilization expands, material and energy conservation is becoming increasingly important. Wear is a major cause of material wastage, so any reduction of wear can result considerable savings. Friction is a principal cause of energy dissipation and considerable savings are possible by improved friction control. It is universally recognized that friction and wear are common phenomena, which occur at machinery components which run together. At present, research in the field of tribology and mechanics of contact fracture of elements and units at variable load modes represents current direction. It causes significant amount of operational failures of technical objects of various purposes. The researchers investigate friction and wear behavior of materials because of adverse effect observed in the performance and life of machinery components. Fretting, being a special kind of material wear, considered in this degree work, takes up to 50% of wear of aircraft parts. All materials in almost all kinds of environment and conditions are subjected to the influence of fretting. For example, according to [2], among the main operational defects in domestic and foreign aircraft gas turbine engines, fretting type of wear constitutes 60% of all types of wear. Flexible couplings and splines, particularly where they form a connection between two shafts and are designed to accommodate some slight misalignment, can suffer severe fretting wear. Jointed structures are another source of fretting problems. Eventually, there is no such thing as a static joint on an aircraft. In turbines, where the turbine disk is either shrink-fitted onto the driving shaft or attached to the shaft by means of a bolted flange and where the blades are fixed into the disk by either a dovetail or fir-tree type fixture – here and not only fretting can take place.