ВПЛИВ ХАРАКТЕРУ НАВАНТАЖЕННЯ НА НАПРУЖЕНИЙ СТАН З'ЄДНАНЬ З М'ЯКИМ ПРОШАРКОМ

Abstract

In the work, the stress state (SS) was simulated by the finite element method using the ANSYS software package in cylindrical nodes with a soft interlayer having an elastic moduluslower than that of the base metal under conditions of power and thermal loading. The influence of the relative thickness of the interlayer on the formation of SS is studied. The fields and diagrams of the distribution of normal (radial, axial, circumferential), tangential and equivalent stresses, as well as the level of maximum and minimum stresses in various sections of the joint are analyzed. It was found that under joint loading by compression and lowering the temperature (during cooling), the level of equivalent stresses is higher in a material with a high temperature coefficient of linear expansion (TCLE), with increasing temperature - with a lower TCLE. In a small area of the base metal near the outer surface at the junction with the interlayer and in the interlayer itself, a complex SS with radial, axial, circumferential and tangential stresses arises. The radial stresses at the junction of the interlayer-material with a large TCLE are compressive, and at the junction of the interlayer-material with a lower TCLE, they are tensile. Axial stresses increase sharply in a material with a larger TCLE and a decrease in a material with a lower TCLE, which causes them to become tensile stresses. Circumferential and tangential stresses increase linearly from zero at the center of the joint to a maximum at the periphery. Equivalent stresses are distributed fairly evenly along almost the entire joint. The nature of the distribution depends little on the thickness of the interlayer, however, the level of stress changes with a decrease in the relative thickness of the interlayer. In the case of an increase in the relative thickness of the interlayer, the equivalent stresses in it increase, which contributes to the activation of the formation of a joint between materials with different thermal expansion rods during diffusion welding with a soft interlayer.