PSI - Issue 60

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

80 6

Static, general step with geometric non-linearity has been used, and the time period is set based on the time period of the loading cycles. C3D8I (8-node linear brick, incompatible modes) elements have been used for the pipe bend region and C3D10 (A 10-node quadratic tetrahedron) elements for the flanges. The mesh is shown in Figure 5.

Figure 5 Mesh of the pipe bend

Finite Element (FE) analysis has been carried out at room temperature and a high temperature of 600 ℃ . The maximum temperature in SGDHR piping system is 550 ℃ . However, a higher temperature is considered for the experiment for acceleration. The material properties considered for the analysis are given in Table 1 [RCC MR (2012)].

Table 1 Material properties considered for the analysis [RCC MR (2012)]

Temperature ( ℃ )

Youngs modulus (MPa)

Poisson’s ratio

Average yield strength (MPa)

Flow stress (MPa)

Room temperature

200000 155000

0.3 0.3

282 135

433 263

600

4. Results and Discussions

4.1 Elastic Analysis

4.1.1 Identification of the critical locations

Elastic analysis has been carried out for the model, as discussed in section 3, at various combinations of pressure and displacements. The hoop stress distribution along the circumference of the pipe bend at 7 bars pressure and 0 mm displacement are shown in Figure 6 and plotted in Figure 7. It is observed that the maximum stress location is slightly above the crown on the outer surface, and the value is 25 MPa.