PSI - Issue 17

Salatiel Pérez Montejo et al. / Procedia Structural Integrity 17 (2019) 123–130 Salatiel Pérez Montejo et al/ Structural Integrity Procedia 00 (2019) 000 – 000

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pressure and temperature. The cool rate is 130°F /hr (Fig. 4). This process takes place in 2 hours 38 min.

Fig.4. Variation of the pressure and temperature during the shut-down of the reactor.

4.1. Evaluation of the structural integrity of the cracked area at the beltline zone with the Finite Element Method. The two transients mentioned above were analyzed with a complete model of the reactor (ANSYS, 2017). Then a submodel was created as it is illustrated in Fig. 5. The beltline zone was discretized with ANSYS Workbench 2019 R1. Several simulations were carried out with different mesh sizes. Convergence was observed with a mesh which has 670550 tetrahedral and hexahedral elements elements (SOLID 186). 1676375 nodes were required and the minimum quality of the elements is 0.188. Regarding the boundary conditions, the displacements along the borders of the submodel were imported from the complete model. Small elements were localized at the neighbourhood of the crack. It is illustrated as a spot on the internal surface of vessel in Fig. 5b. The internal surfaces are loaded with the pressure.

(b)

(a)