Open Access

ARTICLE

A New Damage Mechanics Based Approach for Integrity Assessment of Plant Components

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1 Reactor Safety Division, Bhabha Atomic Research Centre, Trombay, Mumbai. E-mail: mksamal@barc.gov.in. Current address: Department of Mechanical Engineering, Ohio State University, Columbus, Ohio. E-mail: samal.3@osu.edu, Tel: +1-614-6883288

Structural Longevity 2010, 3(2), 127-153. https://doi.org/10.3970/sl.2010.003.127

Abstract

Safety analysis of critical components and the overall plant is a major and important task in the field of mechanical engineering. Therefore, it is essential to know the allowable loads and the corresponding failure behaviour (e.g., crack initiation, growth and instability) of the component. The damage mechanics approaches which incorporate the microscopic processes of ductile fracture (i.e., void nucleation, growth and coalescence) into the material constitutive behaviour has been very successful in predicting the ductile crack propagation in specimens and components irrespective of their geometry, loading types etc. The major drawback of these models is the requirement of a pre-defined size of discretization for the numerical treatment. Hence, these models are not capable of simulation of fracture behaviour in several situations such as miniature specimens, thin films, ductileto-brittle transition regime (where the stable crack growth is of the order of few microns before cleavage initiation), bi-material interface (requirement of different discretization sizes across the interface), zones with steep stress gradients etc. In this work, a new damage mechanics approach based on a nonlocal regularization scheme has been developed and its advantages in tackling the above-mentioned problems has been demonstrated through various examples.

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