1. Reference problem#

1.1. Geometry#

The geometry is chosen deliberately simple, to translate a state of homogeneous stresses and deformations, as is the case in uniaxial traction. This is a volume element represented by a square with side \(\mathrm{0.01mm}\). The modeling is axisymmetric, and the traction takes place with imposed deformation.

1.2. Material properties#

The characteristics set are as follows:

Keyword ELAS:

YOUNG = \(143006.0\mathrm{MPa}\)

NU= \(0.33\)

UN_SUR_M = \(0\)

G2_0= \(0.28\)

The initial values and limits of the parameters to be identified are:

Keyword CIN2_CHAB

Initial value

Inf terminal

Upper terminal

R0

100

0.01

1000

R_I

120

0.01

2000

B

0.0934

0.01

20

K

4.307

0.01

20

W

0.156

0.01

20

G1_0

245

0.01

2000

C1_I

2628

0.01

20000

C2_I

105

0.01

2000000

A_I

1.24

0.01

2000

Keyword LEMAITRE

UN_SUR_K

0.003

0.00001

2000

EXP_N

15

0.01

2000

1.3. Boundary conditions and loads#

\(\mathrm{DY}=0\) on the bottom

\(\mathrm{DX}=0\) on the left side

\(\mathrm{DY}\) imposed on the top, such as:

\(\mathrm{DY}(t)=({\mathrm{EPS}}_{\mathrm{final}}\ast H)/\mathrm{tmax}\ast t\)

With \({\mathrm{EPS}}_{\mathrm{final}}=0.01\)

\(H=0.01\mathrm{mm}\)

\(\mathrm{Tmax}=\mathrm{200s},\mathrm{1000s},\mathrm{2000s},\mathrm{10000s}\)

This corresponds to imposed deformation rates of \({5.10}^{-4}/s,{1.10}^{-3}/s,{5.10}^{-3}/s,{1.10}^{-6}/s\).

1.4. Initial conditions#

Zero stresses and deformations.

1.5. Reference curves#

_images/10000000000002D500000203AD62E34B57A08B6A.jpg

The curves obtained with the initial values of the parameters are as follows:

_images/10000000000002D5000002022C90721E334E057B.jpg