Fig. 1. Continuous ship unloader(capacity : 2000 ton/hour).
Fig. 2. Superstructure of continuous ship unloader.
Fig. 3. Strain gage attached to tension bar member.
Fig. 4. Dimensions of tensile test specimen.
Fig. 5. The scene of tensile test.
Fig. 6. Dimensions of CT specimen.
Fig. 7. Fatigue crack propagation test and measuring of crack.
Fig. 8. The relationship of crack length-cycle.
Fig. 9. The relationship of da/dN-ΔK.
Fig. 10. The relationship of allowable crack length-detection crack length.
Fig. 11. The relationship of Remaining unloading life-detection crack length.
Table 1. Stress measurement results of tension bar when unloading one cargo ship
Table 2. Chemical composition of materials
Table 3. The results of tensile test
Table 4. Conversion life time according to various detection crack length
Table 5. Classification according to dection crack length
Table 6. Inspection cycle according to grade
References
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- NI 611 SEC 12, "Guidelines for Fatigue Assessment of Steel Ship and Offshore Units", Bureau Veritas, 2016.