A method for model sealing performance degradation stochastic model of underwater connector

Abstract

A method for model sealing performance degradation stochastic model of underwater connector features that that sealing contact strength is taken as the characterize quantity of sealing performance, and a connector sealing performance heat-solid finite element analysis parameterized model is established, the connector sealing performance is analyzed, the initial time t1 connector sealing performance quantification index is acquired; Secondly, according to the actual condition of the connector, the corrosion rate prediction model is used to predict the corrosion rate of the upper hub, the seal and the lower hub of the connector, so as to obtain the corrosion amount of the above-mentioned structure and the specific size of each structure after corrosion, structural parameter updating is performed on the connector sealing performance heat-solid finite element analysis parameterized model, and the sealing performance index fs2 of the connector at time t2 is calculated again. Thirdly, by using the same method, the connector sealing performance indexes corresponding at any time t3 and t4 are obtained as fs3 and fs4, respectively. At last, consider that randomness and irreversibility of the deterioration of the sealing performance of the connector, Gamma stochastic process is selected to describe the mechanism of seal performance degradation. The characteristic parameters of Gamma stochastic process are estimated by using the connector seal performance indexes fs1, fs2, fs3 and fs4 at different times, and the connector seal performance degradation stochastic model based on Gamma process is obtained.

Description

technical field [0001] The invention belongs to the technical field of mechanical engineering, and in particular relates to a modeling method for a performance degradation model of an underwater connector sealing structure. Background technique [0002] The underwater connector is the key equipment of the offshore oil and gas underwater production system. It is mainly used for the connection between the underwater production pipelines. The sealing ability is its most important performance index. Since the connector is corroded by production fluid and seawater for a long time during service, and is also subjected to random loads such as ocean currents, the performance degradation of the connector exists objectively. It is necessary to establish a performance degradation model of the connector to obtain the change law of the sealing performance index during the service period. It is convenient for subsequent reliability analysis of connectors. [0003] At present, the contact...

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Problems solved by technology

In fact, the sealing performance is not only affected by the contact stress of the sealing surface, but also by the distribution of the contact stress on the entire effective contact length (Brown M W.Seals and sealing handbook[M].Elsevier SciencePublishers,2007.) , only the size of the contact stress value is used as the characterization of the sealing performance, which affects the accuracy of the sealing performance analysis to a certain extent, and leads to the inaccuracy of the established sealing structure performance degradation model

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