PSI - Issue 42

Diego F. Mora et al. / Procedia Structural Integrity 42 (2022) 224–235

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Diego F. Mora et. al./ Structural Integrity Procedia 00 (2019) 000 – 000

adiabatic condition was assumed. In the presented analysis, it is assumed that heat transfer does not take place through the crack surfaces.

(a)

(b)

(c)

Fig. 3. Cyclic FE model for the cylinder with circumferential crack in red (a) Gray indicates full cylinder, black indicates the slice considered in the FE-model; (b) Slice of the cylinder with finite element mesh with refinement in the middle section (c) Refined region in the middle height where the initial flaw is located.

Table 3. Thermal shock description. Fluid temperatures and HTCs. Time [s] Fluid temperature [°C] Time [°C]

HTC [kW/m 2 °C]

0

250 250 200

0

0

10.5 19.5 33.0 46.5 78.0 2700

67.5

13.5

84

15

90 45 23 23

127.5

16.6 16.6 14.8 14.8

720

1620 2700

Fig. 4(b) illustrates the boundary conditions imposed for the mechanical analysis. The internal pressure is applied on the same internal surface on which thermal shock takes place. In addition, the cylinder is axially preloaded at the top and bottom surfaces. The mechanical analysis does not consider the crack face pressure since in the current implementation of XFEM in ABAQUS, boundary conditions cannot be applied directly to the crack surfaces.