European FITNET Fitness-for-Service Procedure ... - Congrex

Conclusions
• Investigation has demonstrated the ability of the FITNET FFS
fracture module to predict the residual strength of complex thinwalled
structural components.
• Methodology presented for stiffened panels incorporating both
skin and stiffener failure criteria enables a prediction whether
skin or stringer will fail. However, stringer crack K-factor
solution is required.
• The „simplified approach“ by treating the stiffened panels as
simple M(T) panels with equivalent thickness has shown a
potential to predict the residual strength of such complex
structures with a reasonable accuracy.
• FITNET FFS analysis of 4-stringer panels yielded good
estimates of the max load justifying the approximation of
stiffened panels to simple base metal plate.
ESA/ESTEC Workshop on Fracture Control, Noordwijk, NL, 9-10 Feb. 2009 M. Kocak, V. Uz, GKSS 34