TWI Industrial Member Report Summary 899/2008
By I Partridge
The European FITNET consortium was formed in 2002, with the aim of preparing the basis of a European fitness-for-service (FFS) procedure, covering assessment of flaws in welded and non-welded metallic structures. The procedure, which has now been submitted to CEN for publication as a CEN document, is intended for use by all industry sectors, and covers the principal failure/damage modes (fracture, fatigue, creep and corrosion). Further details of the project are given in the FITNET website (www.eurofitnet.org) and proceedings of the end-of-project conference.
The European FITNET consortium has produced the final draft version (MK7) of its European FFS procedure. As a member of all the technical working groups, TWI had access to this draft version of the proposed procedure. As part of the TWI contribution to the FITNET consortium, validation was carried out for the proposed assessment method for blunt locally thinned areas (LTA) in pressure equipment caused by corrosion, erosion, wear or grinding.
This document is one in a series of four TWI Core Research Reports covering various aspects of the validation of the FITNET procedure, namely:
- Application of the LTA assessment procedure (this document).
- Option 4 fracture assessment (direct finite element (FE) simulation of the cracked body).
- Use of the 'Route 4' fatigue assessment procedure (fatigue crack growth rate based).
- Incorporation of weld strength mismatch into fracture assessment.
Determine the validity and conservatism of the MK7 draft FITNET procedure for assessing the FFS of pressurised components containing LTAs.