PSI - Issue 42

Ana Petrović et al. / Procedia Structural Integrity 42 (2022) 236 – 243 Ana Petrovi ć / Structural Integrity Procedia 00 (2022) 000 – 000

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Fig. 2. (a) Locations of interest, Von Mises Stresses, undercarriage, (b) Locations of interest, Von Mises Stresses, slewing platform, (c) Locations of interest, Von Mises Stresses, pylons, (d) Locations of interest, Von Mises Stresses horizontal plates of undercarriage

Table 1. Von Mises stress results at positions. Location σ VM [MPa] Location σ VM [MPa]

Location

σ VM [MPa]

Location

σ VM [MPa]

1 2 3 4 5 6 7 8 9

50.40 27.79 56.56 39.95 55.03 60.83 26.38 58.62 51.19 62.77

14 15 16 17 18 19 20 21 22 23 24 25 26

55.65 27.23 89.60 57.02 24.97 51.58 44.62 14.30 73.74 88.19 23.20

27 28 29 30 31 32 33 34 35 36 37 38 39

73.12 60.26 28.78 73.10 64.54 20.30 68.12 67.29 33.43 28.56 27.65 18.14 19.89

40 41 42 43 44 45 46 47 48 49 50

19.66 35.30 43.47 53.42 53.77

101.00 187.50 184.50 95.49 84.69

10 11 12 13

130.30 161.90 74.72

3.20

111.10 141.30

3. Probability models Probability and reliability theory used in this paper is thoroughly explained in reference by Melchers and Beck (2018), Wang (2021) and O’Connor and al. ( 2016). Somewhat the same principle used in this paper is also applied in case of reliability analysis of large steel hull, as presented by Motok and al. (2022). Here, the idea was to model the actual demand (D) and the capacity of the structure (C) in a form of probability density functions (pdf), so that the margin function (M) is the limit state function, defined in eq. (1): M C D = − (1) Here, a demand is loading, i.e., Von Mises stress of the structure, while the capacity of the structure is represented by yield limit of the material (criterion). So, in order for the structure to be safe, the capacity of the structure has to be larger than its demand in all conditions (M > 0). If the capacity is lower than the demand (M < 0), than the structure is considered as failed. Since the uncertainties of both capacity and demand are included in the analyses, the failure comes with a certain probability.