Numerical simulation method for crack propagation on pitting corrosion pit of RPV pipe based on extended finite element

Abstract

The invention discloses a numerical simulation method for crack propagation on a pitting corrosion pit of an RPV pipe based on an extended finite element. The method comprises the following steps: determining the morphology and size parameters of the pitting corrosion pit generated by an RPV pipe material under an actual working condition through a test; establishing a pitting-pit-containing damage model suitable for the RPV pipeline material; defining load and boundary conditions; setting an XFEM unit enrichment area by calculating stress distribution; and simulating a crack cracking process on the pitting corrosion pit model. According to the method, the influence of the morphology and size of the pitting corrosion pit on the crack initiation position is considered, no prefabricated crack is added in simulation, damage accumulation-cracking whole-process simulation of cracks around the pitting corrosion pit from nothing to nothing under the approximate RPV pipeline working condition is achieved, and the service life of the RPV pipe can be effectively and accurately predicted.

Description

technical field [0001] The invention belongs to the technical field of pitting crack initiation prediction, and in particular relates to a numerical simulation method for crack propagation on pitting pits of RPV pipes based on extended finite elements. Background technique [0002] The reactor pressure vessel (RPV) is an important equipment in the main circuit coolant pressure boundary barrier. It is a nuclear safety first-level equipment and cannot be replaced during the service period of the nuclear power plant. Its life determines the service life of the entire nuclear power plant. Therefore, the sealing design and material selection of the reactor pressure vessel are very important for the safe operation of the equipment. RPV pipe joints generally use austenitic stainless steel as the corrosion-resistant material. Because austenitic stainless steel has good comprehensive properties, it is widely used in various pressure vessels and pipelines and other pressure-bearing eq...

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Problems solved by technology

[0005] Due to the large volume of RPV and the fact that RPV is in the environment of nuclear radiation in actual working conditions, it is difficult to study stress corrosion cracking through laboratory experiments. Therefore, it is urgent to develop a numerical simulation method for pitting crack growth of RPV pipes.

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