The Ship Structure Committee (SCC) announced the publication of two new research reports: "In-Service Non-Destructive Estimation of the Remaining Fatigue Life of Welded Joints" and "Structural Survivability of Modern Liners". The Ship Structure Committee is an interagency committee that sponsors ship structure research projects. It's members include the American Bureau of Shipping, Defence Research Development Canada, Maritime Administration, Military Sealift Command, Naval Sea Systems Command, Transport Canada, U.S. Coast Guard and the Society of Naval Architects and Marine Engineers.
Project SSC-444/SR-1433 "In-Service Non-Destructive Estimation of the Remaining Fatigue Life of Welded Joints
" was performed to determine the feasibility of using non-destructive testing to predict the fatigue life of welded joints. Tests were conducted on large-scale specimens, which realistically modeled details found in ship hulls. Ultrasonic non-destructive testing, both the time of flight diffraction method and the linear phased array method, was performed to detect fatigue cracking in the specimens. The correlation between the crack depths found using ultrasonic testing to the remaining fatigue life of the welded joints was studied. Also investigated was the relationship between crack lengths found by visual observation and the remaining fatigue life of the welded joints. The limited results found through this project do not support any substantial conclusions regarding the use of ultrasonic testing methods used for the prediction of remaining fatigue life.
Project SSC-445/SR-1439 "Structural Survivability of Modern Liners" The analysis is comprised of the following parts:
- Definition of three typical loading conditions for the ship
- Determination of three different flooding scenarios that produce different levels of heel angles and structural loadings of the ship in calm water
- Determination of a realistic wave loading for the flooded scenario
- Evaluation of the ultimate or collapse strength of the ship in both the intact and damaged, heeled conditions
- Comparison of the resulting loading to the strength capabilities of the ship
- Comment on additional local factors that can affect the ultimate strength of the structure.