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Version

4.0

Titrate:

SZLZ101 Calculation of the damage/Method RAINFLOW

Date:

19/01/98

Author (S):

A. Mr. DONORE

Key:

V9.01.101-A

Page:

1/6

Manual of Validation

V9.01 booklet: Tire

HI-75/96/038 - Ind A

Organization (S):

EDF/IMA/MN

Manual of Validation
V9.01 booklet: Tire
Document: V9.01.101

SZLZ101 - Calculation of the damage/Method RAINFLOW

Summary:

The purpose of this test is calculation of the damage starting from a history of loading in stresses.

Starting from a simple history of loading defined by

DEFI_FONCTION

[U4.21.02], the cycles are extracted

elementary by the method of counting of cycles of the RAINFLOW [R7.04.01], then one calculates the damage
elementary associated each cycle, by interpolation on the curve of Wöhler of material.

One tests various possibilities of introducing the curve of Wöhler, as well as the taking into account of the coefficient of
elastoplastic concentration.

To finish, one determines the total damage undergone by the part by cumulating all the elementary damage by
linear rule To mine.

This example is a test of validation of software POSTDAM developed by Department REME, provided in
the manual of validation of version 1.0 of this software.

Results provided by the operator

POST_FATIGUE

[U4.67.01] are completely identical to those provided by

software POSTDAM.

Code_Aster

Version

4.0

Titrate:

SZLZ101 Calculation of the damage/Method RAINFLOW

Date:

19/01/98

Author (S):

A. Mr. DONORE

Key:

V9.01.101-A

Page:

2/6

Manual of Validation

V9.01 booklet: Tire

HI-75/96/038 - Ind A

Problem of reference

1.1 Geometry

The analysis consists in determining the damage undergone by a part in a point to which one provides the history
of loading in stresses.

Starting from a simple history of loading defined by

DEFI_FONCTION

[U4.21.02], they are extracted

elementary cycles by the method of counting of cycles of RAINFLOW [R7.04.01], then one calculates
elementary damage associated each cycle, by interpolation on the curve of Wöhler of
material.
One tests various possibilities of introducing the curve of Wöhler and the taking into account or not of one
elastoplastic coefficient of concentration:

The curve of Wöhler is defined in the form:

(

)

()

LOG

alt

has

alt

> =

alternate stress

1/2

if not

with:

= Young Modulus associated with the curve with fatigue with material,

= Young Modulus used to determine the stresses,

constants of the material a0, a1, a2 and a3,
and

limit of endurance of material.

The curve of Wöhler is defined in the same form and moreover one takes account of a coefficient of
elastoplastic concentration defined by:

(

)

(

)

(

)

(

)

N m

m S

= + -

where

is the acceptable maximum stress,

and

two constants depending on material.

The curve of Wöhler is defined in the analytical form of Basquin:

WITH S

alt

To finish, one determines the total damage undergone by the part by cumulating all the damage
elementary by the linear rule To mine.

1.2

Material properties

Parameters of definition of the curve of Wöhler:

EC.

SSL

55.81

43.06

11.91

1.16

200000.

180.

Parameters of definition of the elastoplastic coefficient of concentration Ke:

126.

0.3

1.7

Parameters of definition of the curve of Wöhler in the form analytical of Basquin:

With

1.001730939 E-14

4.065

History of the loading

(T)

1000.

Code_Aster

Version

4.0

Titrate:

SZLZ101 Calculation of the damage/Method RAINFLOW

Date:

19/01/98

Author (S):

A. Mr. DONORE

Key:

V9.01.101-A

Page:

3/6

Manual of Validation

V9.01 booklet: Tire

HI-75/96/038 - Ind A

Reference solution

2.1

Method of calculation used for the reference solution

This test results from the manual of validation of software POSTDAM version 1.0. Reference solutions
are given in this document.

2.2

Results of reference

The counting of the elementary cycles by method RAINFLOW leads to:

Nb_Cycl = 1

Cycle 1

Vale_Min:

Vale_Max:

1000.

First call to

POST_FATIGUE

Cycle 1

Too bad:

2.858503E4

The calculation of the total damage by linear office plurality To mine:

Too bad: 2.858503E4

Second call to

POST_FATIGUE

Cycle 1

Too bad:

1.224941E2

The calculation of the total damage by linear office plurality To mine:

Too bad: 1.224941E2

Third call to

POST_FATIGUE

Cycle 1

Too bad:

9.377005E4

The calculation of the total damage by linear office plurality To mine:

Too bad: 9.377005E4

2.3

Uncertainty on the solution

Analytical solution.

2.4 References

bibliographical

[1]

Manual of validation POSTDAM 1.0. Baker I., Vatin E. HP-14/93/016/B.

Code_Aster

Version

4.0

Titrate:

SZLZ101 Calculation of the damage/Method RAINFLOW

Date:

19/01/98

Author (S):

A. Mr. DONORE

Key:

V9.01.101-A

Page:

4/6

Manual of Validation

V9.01 booklet: Tire

HI-75/96/038 - Ind A

3 Modeling

With

3.1 Functionalities

tested

Order

POST_FATIGUE_T

[U4.67.01].

Key word

Operands

HISTORY

SIGM:
COUNTING:

“RAINFLOW”

TOO BAD:

“WOHLER”

MATER:`
CORR_KE:

“RCCM”

OFFICE PLURALITY:

“LINEAR”

INFORMATION:

Key word

Operands

Keys

DEFI_MATERIAU

TIRE

A0:

[U4.23.01]

A1:
A2:
A3:
E_REFE:
SSL:
N_KE_RCCM:
M_KE_RCCM:
SM_KE_RCCM:

ELAS

E:
NAKED:

TIRE

A_BASQUIN:
BETA_BASQUIN:

Code_Aster

Version

4.0

Titrate:

SZLZ101 Calculation of the damage/Method RAINFLOW

Date:

19/01/98

Author (S):

A. Mr. DONORE

Key:

V9.01.101-A

Page:

5/6

Manual of Validation

V9.01 booklet: Tire

HI-75/96/038 - Ind A

Results of modeling A

4.1 Values

tested

Identification

Reference

Aster

% difference

NB_CYCL

Cycle 1 VALE_MIN

VALE_MAX

1000.

First call to

POST_FATIGUE

Cycle 1 DAMAGE

2.858503E4

DOMM_CUMU

2.858503E4

Second call to

POST_FATIGUE

Cycle 1 DAMAGE

1.22494E2

DOMM_CUMU

1.22494E2

Third call to

POST_FATIGUE

Cycle 1 DAMAGE

9.377005E4

DOMM_CUMU

9.377005E4

4.2 Parameters

of execution

Version: 3.06.18
Machine: CRAY C90
Overall dimension memory:

8 MW

Time CPU To use:

2.9181 seconds