Fracture mechanics based integrity assessment of structural components

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					Fracture mechanics based integrity assessment of structural components requires knowledge
of the crack tip driving force. The estimation of elastic-plastic fracture mechanics parameters
of semi-elliptical surface cracks is practically important in structural integrity assessment of
defective components. However, the estimation of crack tip driving forces for semi-elliptical
surface cracks poses difficulties due to its three dimensional nature. Although the
standardised procedure BS7910 for instance does provide a closed form solution for a single
surface flaw, it is based on 20 year old finite element analyses. Closed form solutions for
multiple flaws are not available at all.
Due to the complexity of the problem, only a limited number of papers exist in the literature
on the structural integrity assessment of structural components containing multiple flaws.
There is considerable disagreement between the flaw interaction and combination rules
provided in different standardised fracture assessment procedures. Some of the codes
considered are based either on flaw depth or flaw length only, while others take into account
both flaw depth and length. The accuracy and justification of the methods included in the
standardised documents are often unknown and unjustifiable
This report will provide a generic insight in the basics of fracture mechanics based critical
assessments for multiple flaws. The main objective of the project can thereby be described
as:
‘An experimental investigation and computational analysis of twin coplanar surface flaws in
wide plates.’