PSI - Issue 5

Martin Krejsa et al. / Procedia Structural Integrity 5 (2017) 1283–1290 Martin Krejsa et al./ Structural Integrity Procedia 00 (2017) 000 – 000

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(a)

(b)

Fig. 3. Resulting histograms of the calculation for t = 35 years of structural operation: (a) load effect E ( N ) ; (b) reliability function G fail .

Fig. 4. Resulting probabilities of random events U, D and F for first 60 years of structural operation under various load.

When the probability of failure P f according (7) and (10) exceeds the specified designed probability, P d , the inspection should be performed. The Tab. 3 include a table with numerical values for the final inspection times - for the first inspection and subsequent inspections resulting from the conditional probability pursuant to (11) and Fig. 1.

Table 3. Calculated times for the first five inspection of the structural element. Inspection No. Time of inspection [years] 1 35 2 46 3 48 4 50 5 51

5. Conclusions

The article demonstrates probability calculation of the fatigue damage prediction of short edge crack under various load using the newly developed Direct Optimized Probabilistic Calculation (“DOProC”), which appears to be a very efficient tool to make probabilistic assessment of the structural reliability on the basis of the exact definition of the acceptable size of the fatigue crack. The theoretical model of fatigue crack progression is based on a linear fracture mechanics and Paris-Erdogan law. The computational procedure is capable to make probabilistic assessment of the structural reliability on the basis of the exact definition of the acceptable size of the fatigue crack. The probabilities