PSI - Issue 7

E. Vacchieri et al. / Procedia Structural Integrity 7 (2017) 182–189

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E. Vacchieri et al. / Structural Integrity Procedia 00 (2017) 000–000

Fig. 1. Flow diagram representing the analysis in the present study (adapted from Holdsworth (2010, 2011)).

The procedure is composed of four steps:

step 1 is made up of constitutive model definitions based on a comprehensive material characterisation campaign and FE simulation strategy; step 2 allows the identification of critical location conditions in the studied component and the definition of the testing condition of step 3; step 3 comprises the fatigue, creep rupture and creep-fatigue experimental tests and the definition of the damage summation diagram; step 4 corresponds to the assessment and validation of the whole procedure by service-like TMF tests that simulate the critical location conditions.

Further details about the developed procedure can be found in Vacchieri (2014); Vacchieri et al. (2016); Vacchieri (2016, 2017).

3.2. First Stage Blade Lifing Results and comparison with Field Feedback

The assessed and validated lifing procedure has been applied to the whole component model. The multi-iteration FE simulation output of the start-up / shut-down transient is post-processed by a developed Ansys macro that analyses the last simulated cycle data for all the part nodes. These data are used to calculate for each node the damage fractions by using the developed strategy and they are summed up upon the chosen summation locus. The final outcome are blade maps for the estimated life that highlight the critical locations. The followed procedure is described in the flow chart of Fig.2. The critical locations identified through this procedure have been compared with available field feedback and the agreement is very good and satisfactory, as shown in Fig. 3.