1. Reference problem#

1.1. Geometry#

We consider a 1×1 mm square test piece comprising 4 elements.

_images/10000201000002FC0000024632A555F784A31609.png

Figure 1-1: Square of 4 elements in tension

1.2. Material properties#

We adopt a Von Mises elasto-plastic behavior law with isotropic work hardening TRACTION whose traction curve is given point by point:

\(\mathrm{\epsilon }\)

0.0027

0.005

0.005

0.01

0.01

0.015

0.02

0.03

0.04

0.05

0.05

0.05

0.075

0.1

\(\mathrm{\sigma }\) \(\mathit{MPa}\)

555

589

589

631

631

657

676

691

704

725

741

741

741

772

794

0.125

0.15

0.2

0.2

0.3

0.3

0.4

0.5

0.6

0.7

0.8

0.8

0.9

812

827

851

887

887

97

912

933

950

965

978

990

The deformations used in the behavior relationship are linearized deformations. Young’s modulus \(E\) is \(200\mathit{GPa}\) while the Poisson’s ratio \(\mathrm{\nu }\) is equal to \(\mathrm{0,3}\).

The Weibull model coefficients used are as follows:

\(m=8\),

\({V}_{0}=125\mathrm{\mu }m\),

\({\mathrm{\sigma }}_{u}=2630\mathit{MPa}\).

1.3. Boundary conditions and loads#

With reference to Figure 1-1, the boundary conditions are as follows:

  • \(\mathit{BAS}\): movements blocked according to \((X)\mathit{et}(Y)\),

  • \(\mathit{GAUCHE},\mathit{DROITE}\): movements blocked following \((X)\).

    The pressure is affected on segment \(\mathit{HAUT}\) via PRES_REP following \((Y)\) and varies as a function of time as follows:

instant \(t\)

0

1

\(P(t)\)

0

-0.5x104

The pressure is imposed using 5 steps up to 0.2 s and 10 steps up to 10 s.

1.4. Initial conditions#

Zero stresses and deformations.