G0301302 改良9Cr-1Mo鋼薄肉大口径配管の貫通き裂に対するJ積分評価法  [in Japanese] G0301302 J-integral Evaluation Method for a Through Wall Crack in Thin-walled Large Diameter Pipes Made of Mod.9Cr-1Mo Steel  [in Japanese]

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Abstract

This paper describes a J-integral evaluation procedure applicable to unstable failure analysis for a circumferential through wall crack in a pipe. Japan Sodium cooled Fast Reactor (JSFR) pipes are made of Mod.9Cr-1Mo steel. The fracture toughness of the material is inferior to that of conventional austenitic stainless steels. In addition, JSFR pipe has small thickness and large diameter and displacement controlled load is predominant. Therefore, the load balance in such piping system changes by crack extension and 2 parameter method using J-integral is applicable to unstable failure analysis for the pipes under such conditions. As a J-integral evaluation method for circumferential through wall crack in a cylinder, EPRI has proposed a fully plastic solution method. However, the geometry of JSFR pipe and material characteristics of Mod.9Cr-1Mo steel exceed the applicable range of EPRI's method. Therefore, a series of elastic, elastoplastic and plastic finite element analyses (FEA) were performed for a pipe with a circumferential through-wall crack to establish a J-integral evaluation method applicable to such conditions. J-integrals obtained from the FEA were resolved into elastic, local plastic and fully plastic components. Each component was expressed as a function of analytical parameter, such as pipe geometries, crack size, material characteristics and so on. As a result, a simplified J-integral evaluation method was proposed.

Journal

  • The Proceedings of Mechanical Engineering Congress, Japan

    The Proceedings of Mechanical Engineering Congress, Japan 2015(0), _G0301302--_G0301302-, 2015

    The Japan Society of Mechanical Engineers

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