1. Reference problem#

1.1. Geometry#

The geometry studied is that of a bi-metal tank slice, limited to 45 degrees in azimuth.

_images/Cadre1.gif

1.1.1. Defect considered#

In method \(K\beta\), the defect is not modeled in the mesh. The mesh makes it possible to calculate the stresses at the nodes. A post-processing is then applied to calculate the stress intensity factor by the \(\beta\) method from the stresses at the nodes (the method is detailed in [R7.02.10]).

For this test, the defect in question is elliptical and has a longitudinal orientation. Its dimensions are as follows (see figure below):

  • depth: \({\mathit{prof}}_{\text{def}}\mathrm{=}\mathrm{6mm}\)

  • width: \(\mathrm{2b}\mathrm{=}\mathrm{60mm}\)

  • offset in the coating: \(\mathit{deca}\mathrm{=}–\mathrm{0,2}\mathit{mm}\)

_images/10011412000069D500004A6A140E8084EC343E1E.svg

1.2. Material properties#

For thermal calculation:

Two properties are specified, they are:

  • LAMBDA: isotropic thermal conductivity as a function of temperature, expressed in \({\mathit{W.m}}^{\mathrm{-}1}\mathrm{.}{K}^{\mathrm{-}1}\),

  • BETA: volume enthalpy as a function of temperature, expressed in \({\mathit{J.m}}^{\mathrm{-}3}\).

For coating:

Temperature ( \(°C\) )

LAMBDA

0

14.7

20

14.7

50

15.2

100

15.8

150

16.7

200

17.2

250

18

300

18.6

350

19.3

Temperature ( \(°C\) )

BETA

0

0.000000.E+00

50

1.102100.E+08

100

3.013300.E+08

150

5.014300.E+08

200

7.081300.E+08

250

9.188800.E+08

300

1.132910.E+09

350

1.348980.E+09

For the base metal:

Temperature ( \(°C\) )

LAMBDA

0

37.7

20

37.7

50

38.6

100

39.9

150

40.5

200

40.5

250

40.2

300

39.5

350

38.7

Temperature ( \(°C\) )

BETA

0

0.000000.E+00

50

1.061900.E+08

100

2.903300.E+08

150

4.829100.E+08

200

6.832800.E+08

250

8.921600.E+08

300

1.109440.E+09

350

1.335060.E+09

For mechanical calculation:

Four parameters are filled in, they are:

  • \(E\):

Young’s modulus, expressed in \(\mathit{Pa}\),

  • \(\mathit{nu}\mathrm{=}0.3\)

Poisson’s ratio,

  • ALPHA:

isotropic thermal expansion coefficient, expressed in \(°C\),

  • TEMP_DEF_ALPHA = 20:

value of the temperature at which the values of the thermal expansion coefficient ALPHAont were determined, expressed in \(°C\).

For coating:

Temperature ( \(°C\) )

\(E\)

0

1.985E+11

20

1.97E+11

50

1.95E+11

100

1.915E+11

150

1.875E+11

200

1.84E+11

250

1.8E+11

300

1.765E+11

350

1.72E+11

Modeling a

Modeling b

Temperature ( \(°C\) )

ALPHA

Temperature ( \(°C\) )

ALPHA

0

1.756E-05

20

1.764E-05

20

1.64E-05

50

1.7787E-05

50

1.654E-05

100

1.8019E-05

100

1.68E-05

150

1.8225E-05

150

1.704E-05

200

1.8575E-05

200

1.72E-05

250

1.8568E-05

250

1.75E-05

300

1.8768E-05

300

1.777E-05

For the base metal:

Temperature ( \(°C\) )

\(E\)

0

2.05E+11

20

2.04E+11

50

2.03E+11

100

2E+11

150

1.97E+11

200

1.93E+11

250

1.89E+11

300

1.85E+11

350

1.8E+11

Modeling A

B Modeling

Temperature ( \(°C\) )

ALPHA

Temperature ( \(°C\) )

ALPHA

0

1.2878E-05

20

1.3002E-05

20

1.122E-05

50

1.3198E-05

50

1.145E-05

100

1.3521E-05

100

1.179E-05

150

1.382E-05

150

1.214E-05

200

1.4102E-05

200

1.247E-05

250

1.4382E-05

250

1.278E-05

300

1.4682E-05

300

1.308E-05

1.3. Boundary conditions and loads#

The boundary conditions imposed are those of an axisymmetric system.

Two types of loads are applied:

  • heat exchange in the inner skin,

  • fluid pressure in the inner skin.