Turnbull, A; Crocker, L E (2013) Finite element analysis of the effect of residual stress on the distribution of stress and strain associated with a single pit. NPL Report. MAT 60

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Abstract

Previously, finite element analysis had been carried out to determine the stress and strain distribution associated with a single corrosion pit of varying geometry in a cylindrical specimen of steel stressed remotely in tension. In service, residual stresses are often present at the surface as a consequence of the surface finishing process and are known to impact on the likelihood of cracking. Relaxation of that stress can occur when new free surface is created. The question then posed is the extent to which the residual stress and strain are redistributed in the presence of a pit. Assuming an axial tensile stress at the surface, it is shown that the corrosion pit concentrates the stress in such a way that it becomes compressive local to the pit in the longitudinal direction and exceeds the tensile proof stress in the transverse direction. Despite local plasticity, the stress is a maximum near the mouth of the pit. This reflects the gradient in tensile stress since previous analysis assuming only applied stress indicated that the local plasticity would shift the maximum in stress away form the pit mouth. Indeed when applied and residual stress are combined the maximum in stress is shifted away from the pit mouth to the pit base.

Item Type:	Report/Guide (NPL Report)
NPL Report No.:	MAT 60
Keywords:	residual stress, corrosion pit, finite element analysis
Subjects:	Advanced Materials Advanced Materials > Corrosion
Last Modified:	02 Feb 2018 13:14
URI:	http://eprintspublications.npl.co.uk/id/eprint/6098

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