The installation load prediction method of interference fit between the submarine elliptical pipeline and mechanical connector

Abstract

For damaged submarine pipelines, interference fit is necessary for the repair technology by the mechanical connector. Due to manufacturing error and asymmetric load, the ovality occurs on pipeline and increases the difficulty to install the connector. For ensure safety, it is necessary to consider the interference and ovality of pipeline to predict the installation load. In this paper, the software ANSYS was used to establish the finite element model of the connector and pipeline, then the contact characteristics on the contact surface were analyzed. According to the static equilibrium equation, the installation load of interference fit is equivalent to the friction force and is proportional to the contact pressure, it could be predicted according to the contact pressure. The results indicate that, on the premise of the same equivalent interference, the contact force and contact area on the contact surface were independent of the ovality of pipeline. For the pipelines with different ovality, the installation load can be predicted based on contact force of the circular pipeline. Some cases are conducted to verify the accuracy of the established prediction formula. The load prediction formula effectively solves the problem of submarine pipeline repair connection and has high engineering application value.