3. Modeling A#

3.1. Characteristics of modeling#

This is an X- FEM modeling, in plane deformations, where the interfaces are defined by level functions (normal level sets noted \(\text{LN}\)).

The equations of the level functions for the three horizontal cracks are as follows:

\(\text{LN}1=Y-0.5\) eq 3.1-1

\(\text{LN}1\mathrm{=}Y\mathrm{-}1.5\) eq 3.1-2

\(\text{LN}2=Y-2.5\) eq 3.1-3

\(\text{LN}3=Y-3.5\) eq 3.1-4

3.2. Characteristics of the mesh#

_images/Object_11.png

Figure 3.2-a: The modeling mesh A.

The mesh comprises 4 cells of the QUAD4 type, represented in FIG. 3.2-a.

For example, we notice in this figure that node \(\mathrm{N1}\) sees 2 cracks. It must therefore be enriched twice and it then has the kinematic degrees of freedom DX, DY, H1X, H1Y, H2X and H2Y. Since the contact is active, node \(\mathrm{N1}\) also has Lagrange degrees LAGS_C and LAG2_C.

On the other hand, we notice for example that mesh \(\text{M1}\) « sees » 4 cracks. The element associated with this mesh will therefore store the fields of the four cracks, regardless of the degrees of freedom associated with its nodes.

3.3. Tested sizes and results#

The movements at the level of the crack lips are tested. The DX displacement should follow function \(\text{Depl\_X}\) in equation 2.1-1. The displacement DY must follow function \(\text{Depl\_Y}\) in equation 2.1-2. The stair deformation of FIG. 3.4-a is obtained.

Identification

Reference

SOMM_ABSpour DX- \(\text{Depl\_X}\) (master side)

0

SOMM_ABSpour DY- \(\text{Depl\_Y}\) (master side)

0

SOMM_ABSpour DX- \(\text{Depl\_X}\) (slave side)

0

SOMM_ABS for DY- \(\text{Depl\_Y}\) (slave side)

0

Table 3.3-1

_images/10000000000001A500000261F61AD6896559AD99.jpg _images/10000000000001A500000261AE4D0936369D3845.jpg

Figure 3.4-a: Deformed structure.

We test the value of \({E}^{e}\) produced by the POST_ERREUR operator.

Identification

Reference type

Reference value

Tolerance

Ee

“ANALYTIQUE”

2.6 107

0.1%

We test the value of \({\parallel u\parallel }_{{L}^{2}}\) produced by the POST_ERREUR operator.