PSI - Issue 62

Ettore De La Grennelais et al. / Procedia Structural Integrity 62 (2024) 763–772 Author name / Structural Integrity Procedia 00 (2019) 000 – 000

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f) Uncertainties about local deteriorations of elements (e.g., corroded or deformed elements) that may disturb the theoretical distribution of mass and stiffness characteristics of the elements. The sum of the uncertainties leads to estimating a possible error of the calculated values around ±10% compared to the observed actual value. Given the above, the maximum allowable error for passing the test, i.e., the maximum sum of possible errors in the comparison between observed and calculated values, is defined as: For the above, it is defined as follows: err TOT,i =err FEM,i +err stat,i +err var,i the maximum allowable error for passing the test, i.e., the maximum sum of possible errors in the comparison between observed and calculated values. Therefore, the test is considered passed if the ratio between any frequency calculated via finite element model (FEM) and the observed frequency remains below the maximum allowable total error; in other words, when the following inequality is verified: f FEM f av