Simulation of Strain Relaxation in Threaded Joints of Pipelines of Hydraulic and Pneumatic Systems using the Finite Element Method

Abstract

The paper proposes a computational and experimental technique to determine stress relaxation in the critical threaded connections of the hydraulic and pneumatic systems pipelines using the finite element method to ensure their long service life (25 years) at the normal temperature. The technique is based on using the elastic material constants and the residual strain (creep strain) parameters characterizing alteration in the threaded joint parts rigidity over time. Parameters characterizing the residual strain were determined from calculation models developed using experimental data obtained from studying stress relaxation of the 25Kh17N2B-Sh (25Х17Н2Б-Ш) corrosion-resistant steel and the M1 grade copper. Force distribution along the thread turns of one of the threaded connections under consideration was comparatively analyzed in a tightened state obtained by the finite element method and by the force distribution diagram according to N.E. Zhukovsky. Satisfactory coincidence of the force distribution along the thread turns confirmed correctness of the calculated finite element model for the connection under consideration and adequacy of the accepted assumptions. The paper describes algorithm and presents results of simulating stress relaxation for four standard sizes of the threaded connections if operating for 25 years

Please cite this article in English as:

Proskurin А.V., Sayun S.P. Simulation of strain relaxation in threaded joints of pipelines of hydraulic and pneumatic systems using the finite element method. Herald of the Bauman Moscow State Technical University, Series Mechanical Engineering, 2024, no. 1 (148), pp. 69--85 (in Russ.). EDN: EMVIIS

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