Numerical Fatigue Test Method of Welded Structures Based on Continuum Damage Mechanics

Lee, Chi-Seung; Kim, Young-Hwan; Kim, Tae-Woo; Yoo, Byung-Moon; Lee, Jae-Myung

Journal of KWJS 2008;26(3):67-73.
Published online July 31, 2008.

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Numerical Fatigue Test Method of Welded Structures Based on Continuum Damage Mechanics

Chi-Seung Lee, Young-Hwan Kim, Tae-Woo Kim, Byung-Moon Yoo, Jae-Myung Lee

Abstract

Fatigue life evaluation of welded structures in a range of high cycles is one of the most difficult problems since extremely small plastic deformation and damage occur during the loading cycles. Moreover, it is very difficult to identify the strong non-linearities of welding, inducing residual stress. In this paper, numerical fatigue test method for welded structures was developed using continuum damage mechanics with inherent strain. Recently, continuum damage mechanics, which can simulate both crack initiation at the micro-scale level and crack propagation at the meso-scale level, has been adopted in the fracture related problem. In order to consider the residual stresses in the welded strictures, damage calculation in conjunction with welding, inducing inherent strain, was proposed. The numerical results obtained from the damage calculation were compared to experimental results.

Key Words: Welded structures, Continuum damage mechanics, High cycle fatigue, Inherent strain method, Residual stress