Study of fatigue fracture characteristics for duplex stainless steel STHE welded joint specimen

Thin Thin Htut

Tanaka Satoyuki

Ma Donghui

Okada Jun

Honnami Masahito

Shinoda Kaoru

Abe Masamitsu

Katayama Takeru

Engineering Failure Analysis

A shell and tube heat exchanger (STHE) welded joint is considered for fatigue fracture mechanism. The joint is made up of a protruding tube fabricated to a tubesheet by means of welding. A super duplex stainless steel (DSS) material is used for the tube and tubesheet. Fatigue test was newly conducted using the single tube test specimen. The initial cracking plane was moved from the minimum sectional-area plane that was perpendicular to the loading direction, and the crack growth was almost planar. Stress analysis is carried out using finite element method (FEM) and the stress distributions are carefully studied by comparing the simple perforated plate. In addition, three-dimensional crack propagation (CP) simulation is performed employing extended finite element method (X-FEM). Fracture phenomenon is verified using the experimental and numerical crack front geometries. The fracture mechanics parameter is evaluated and verified with empirical formulae. CP behaviors are carefully discussed based on the fracture mechanics parameter. The CP life is presented for three loading amplitudes. The FAT class of the STHE welded joint is studied based on the available design standards such as BS, IIW and JSSC. Finally, the fatigue fracture characteristics of the STHE welded joint specimen are shown through the experimental and numerical methods.

Fatigue fracture

Super DSS STHE welded joint

Fatigue test

CP simulation

Fracture mechanics parameter

CP behaviors

FAT class

英語

Elsevier

© 2023. This manuscript version is made available under the CC-BY-NC-ND 4.0 license https://creativecommons.org/licenses/by-nc-nd/4.0/

This is not the published version. Please cite only the published version.

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[DOI] https://doi.org/10.1016/j.engfailanal.2023.107763 ～の異版である