PSI - Issue 60

R.P. Pandey et al. / Procedia Structural Integrity 60 (2024) 324–334 R.P. Pandey/ StructuralIntegrity Procedia 00 (2023) 000 – 000

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motion to cylindrical rollers [Fig. 2(b)]. Due to significantly higher toughness and hardness of rollers compared to pressure tube, the rollers were modelled as rigid bodies. These modelling techniques resulted in significant lower computation cost without compromising the desired output. The geometrical dimensions of pressure tube, end-fitting and roller are provided in Table-1.

Fig. 2: (a) 3D view of the roller assembly before the rolling process and (b) typical spiral motion of the rollers in inner surface of pressure tube

Table 1: Geometrical dimensions of different components of a rolled joint used in FE simulation

S.N.

Part Detail End fitting

OD (mm)

ID (mm)

Model Description

1 2 2 3 4

143

90

3D Solid Continuum Element

End fitting Length

90 mm

Pressure Tube

90

83

3D Solid Continuum Element

Pressure Tube Length

82 mm

Roller diameter

26.72 mm

Analytical Rigid Surface

3.2. Material properties input to the model

For finite element simulation of the rolling and subsequent pull-out process at different temperatures, the thermo physical and mechanical properties of Zr2.5Nb pressure tube are required. These data have been taken from literature (Christodoulo 2000; Cheadle 2010; Fong 2015; Samal et al. 2020, 2022). The important materials properties of Zr2.5Nb pressure tube and their variation with temperature are provided in Figs. 3 to 6 respectively.

15.5 16 16.5 17 17.5 18 18.5 19

(W/mK)

Thermal Conductivity

0

200

400

600

800

1000

1200

Temperature (K)

Fig. 3: Variation of thermal conductivity of Zr2.5Nb pressure tube with temperature as used in FE analysis