IFMASS10

Figure 27: Procedure for determination of safety margins

6. END REMARKS

When the nominal stresses significantly exceed half of yield strength, pure LEFM-

analysis does not consider the risk of underestimation of the crack driving force and the

results could be unsafe. When the plasticity correction is not considered, the results of

LEFM do not give any warning and results validity is questionable. In most complex

cases is better to carry out a robust EPFM analysis, giving valid results from LEFM to

EPFM. In case of corresponding conditions elastic-plastic analysis passes in linear elastic

one and in this way not only become simpler, but gives the results without ambiguity.

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