1. Reference problem#

1.1. Material properties#

The material properties are as follows:

  1. Young’s modulus: \(E\mathrm{=}2.E+05\mathit{MPa}\);

  2. Poisson’s ratio: \(\nu =0.3\);

  3. Thermal expansion coefficient: \(\alpha =1.E–05\mathrm{m.}°{C}^{-1}\).

The characteristics specific to the calculation RCC -M are:

  1. material constants for calculating \(\mathrm{Ke}\): \(n=0.2\), \(m=\mathrm{2 }\);

  2. Young’s modulus of reference: \({E}_{\mathit{REFE}}\mathrm{=}2.E+05\mathit{MPa}\);

  3. allowable stress: \(\mathrm{Sm}=200\mathrm{MPa}\).

The Wöhler curve is defined analytically: \({N}_{\mathrm{adm}}=\frac{{5.10}^{5}}{{S}_{\mathrm{alt}}}\)

Note:

To validate the consideration of the elastoplastic concentration factor \(\mathrm{Ke}\) , some calculations are carried out with a lower or higher allowable stress: \(\mathit{Sm}=50\mathit{MPa}\) (C modeling) and \(\mathit{Sm}=2000\mathit{MPa}\) (D and E modeling) .

1.2. Evolution of constraints#

The constraints on the analysis segment are not calculated but read directly from a table. The only non-zero component of the stress tensor is \({\sigma }_{\mathrm{yy}}\). Two transients are considered:

Instant

Thermal constraints

Stress due to pressure

Mechanical stress (moments and efforts)

Constraints total es

Abscissor

Abscissor

Abscissor

Abscissor

0

1

2

0

1

2

0

1

2

0

1

2

1

50

100

150

40

0

40

0

0

-80

90

100

110

2

0

50

-100

0

50

0

0

0

10

0

100

-90

3

0

0

50

10

-10

-200

90

-40

50

100

-50

-100

4

0

0

0

0

0

0

0

0

0

0

0

0

Table 1.2-1 : Definition of constraints \({\mathrm{\sigma }}_{\mathit{yy}}\) (in \(\mathit{MPa}\)) for the moments of situation 1 as a function of the curvilinear abscissa

Instant

Thermal constraints

Stress due to pressure

Mechanical stress (moments and efforts)

Constraints total es

Abscissor

Abscissor

Abscissor

Abscissor

0

1

2

0

1

2

0

1

2

0

1

2

1, 5

50

100

150

40

0

2**0**

0

0

-80

90

100

9**0**

2, 5

0

50

-100

0

50

0

0

0

10

0

100

-90

3, 5

0

0

50

10

-10

-200

90

-40

50

100

-50

-100

Table 1.2-2: Definition of the constraints \({\sigma }_{\mathit{yy}}\) (in \(\mathit{MPa}\)) for the moments of situation 2 as a function of the curvilinear abscissa

These transients do not aim to represent a specific real transient, but to cover all possible constraints (constant, linear or non-linear evolution of the stress in thickness).

Two other situations are taken into account in this test case. They are provided in the form of two torsors and a unit stress tensor.

Situation 3 is composed of a state A that corresponds to instant 3 of situation 1 and of a state B that corresponds to instant 2 of situation 1. It also consists of a thermal transient which is that of situation 1.

Situation 4 is composed of a state A that corresponds to the instant 1.5 of the situation 2 and of a state B that corresponds to the instant 3.5 of the situation 2. It also consists of a thermal transient which is that of situation 2.

State

Stress due to pressure

Mechanical stress (moments and efforts)

Restraints total mechanical constraints**

Abscissor

Abscissor

Abscissor

0

1

2

0

1

2

0

1

2

A

10

-10

-200

90

-40

50

100

-50

-100

B

0

50

0

0

0

10

0

100

-90

Table 1.2-3: Definition of the constraints \({\mathrm{\sigma }}_{\mathit{yy}}\) (in \(\mathit{MPa}\)) of situation 3 as a function of the curvilinear abscissa

State

Stress due to pressure

Mechanical stress (moments and efforts)

Restraints total mechanical constraints**

Abscissor

Abscissor

Abscissor

0

1

2

0

1

2

0

1

2

A

40

0

2**0**

0

0

-80

90

100

9**0**

B

10

-10

-200

90

-40

50

100

-50

-100

Table 1.2-4: Definition of constraints \({\sigma }_{\mathit{yy}}\) (in \(\mathit{MPa}\)) of situation 4 as a function of the curvilinear abscissa