摘要：The effect of defects on the mechanical properties of joints of functionally gradient materials, which depends on their shape, operating conditions, and the nature of the load, is considered. The presence of defects in the welded joints significantly reduces the working ability of the structures and, under certain conditions, can lead to their destruction. The problem of the strength of structures that have welded joints is because of the installation of local stress concentrators, near defects of the cracks in which the stresses are well above average. To determine the strength of welded joints and to establish the requirements for their quality, a mathematical model is built that allows you to investigate the impact of the most likely defects on the strength of the joints. The defects taking place in the welding joints on the load-bearing capacity of the structures can be realized by the necessary criterion of local destruction of К1с and the action of operational loads. Based on the value of the stress intensity factor and the value of the heat flux acting on the structure found by the model, by which the stresses are formed in the joint, it is possible to determine the limiting values of the defect size, at which this defect will remain in equilibrium without forming the main crack. The adequacy of the research results obtained was theoretically verified by the strength of welded joints of aluminum alloys, taking into account hot cracks in them. The deformation strengthening of welded joints, which occurs in high-strength complex alloyed aluminum alloys, reduces their strength because of the appearance of intermetallic phases in them, and welds.
其他摘要：Розглядається вплив дефектів на механічні властивості з’єднань функціонально-градієнтних матеріалів, який залежить від їх форми, умов експлуатації, та характеру навантаження. Наявність дефектів у зварних з’єднаннях суттєво знижують робочу здатність констр
