PSI - Issue 60

Rosy Sarkar et al. / Procedia Structural Integrity 60 (2024) 75–92 Rosy Sarkar/ StructuralIntegrity Procedia 00 (2019) 000 – 000

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Figure 8 Hoop stress distribution at 7 bars pressure and 20 mm displacement a) outer surface and b) inner surface

Figure 9 Plot of hoop stress distribution at 7 bars pressure and 20 mm displacement

4.1.2 Ratcheting check using Odonnel Porowski Diagram (ASME code) As per ASME NH, prediction of ratcheting is done using Odonnel Porowski Diagram (OPD), shown with thick lines in Figure 10 and Figure 11 [ASME (2013)]. The primary stress parameter (X) is calculated as per equation (1). = ( + )max ÷ (1) Where, (P L + P b /K t ) max is the maximum value of the primary stress intensity, adjusted for bending via K t , during the cycle being evaluated, and S y is the average of the S y values at the maximum and minimum wall averaged temperatures during the cycle being evaluated.