Modeling of the stress-deformed state of a fitting branch pipe with a linear defect

• Main Authors: Rubtsov, Aleksey, Kulakov, Petr, Mukhametzyanov, Zinur, Afanasenko, Vitaliy, Yakubova, Polina
• Format: Conference Proceeding
• Language: English
• Subjects: Defects; Deformation; Fittings; Fracture mechanics; Norms; Pipe fittings; Raw materials; Repair; Stress concentration
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0071836

The connection pipes of technological apparatuses are an integral constructural element, as they serve for the input, output of raw materials and products through the pipelines connected to them. In the process of repair and operation, the formation of extended linear, most dangerous, defects are possible on the surface of the nozzles. Technical standards have established norms for the size of such defects, according to which the defect is considered acceptable or unacceptable, depending on the operating conditions of the device. In case of exceeding the permissible dimensions of the detected defect, the device is subject to decommissioning and repair. In exceptional cases, temporary operation with defects exceeding the permissible norms is allowed when calculating and justifying from the point of view of fracture mechanics by a specialized scientific and technical organization specializing in such calculations. Linear defects are the most unfavourable from the point of stress concentration and can be places of premature failure under certain conditions. The presence of such defects on the branch pipes of the fittings, especially on their inner side under the influence of aggressive working media, can accelerate the transition of the apparatus to the limiting state. Also, the form of a linear defect and its location on the surface of the branch pipe can have a significant impact on the resource and safe operation of the apparatus. At present, research on numerical modelling and assessment of the stress-deformed state of objects and elements under various conditions is relevant and effective. This paper investigates the relationship between the shape and location of a longitudinal extended linear defect on the inner.