4. B modeling#

4.1. Characteristics of modeling#

In this modeling, the extended finite element method (\(\text{X-FEM}\)) is used. We define an enrichment radius \({R}_{\mathit{ENRI}}=0.5\). Finite elements are linear.

4.2. Characteristics of the mesh#

Same as modeling A.

4.3. Tested sizes and results#

On the background of the crack in opening \(P2=(a\mathrm{,0})\), the stress intensity factor \({K}_{I}\) given by the command CALC_G is tested, compared to the analytical value explained in paragraph [5].

For method \(G-\mathit{thêta}\) (command CALC_G), the following crowns of the theta field are chosen:

Crown 1

Crown 2

Crown 3

Crown 3

Crown 4

Crown 5

Crown 6

Rinf

0.1

0.2

0.2

0.3

0.3

0.1

0.2

Rsup

0.2

0.3

0.3

0.3

0.4

0.4

0.4

Identification

Reference type

Reference value

Precision

CALC_G /K1

“ANALYTIQUE”

0.9648

1.0%

CALC_G /K2

“ANALYTIQUE”

0.00

0.00

0.001

CALC_G /G

“ANALYTIQUE”

9.3084E-7

2.0%

4.4. Additional results#

By activating the contact algorithm, we obtain the solution moving in the vicinity of the crack given to [] (to be compared with post-treatment).

On the other hand, we find an analytical conclusion, namely the abscissa of the point at which the crack begins to open:

\(c=-\frac{a}{3}\approx -0.33\)

Indeed, in post-treatment, we analyzed the contact pressures to determine the abscissa of the last point of contact. Graphically, it is estimated that the pressure falls sharply around the abscissa point \({x}_{c}\approx -0.325\), which validates the estimation hypothesis of \({K}_{I}\).

_images/100000000000046100000351FE7542CF6FE32CD0.png

Figure 4.4-1: contact crack closure facies

_images/10000000000015BD00000F2AD6280212F23A7796.png

Figure 4.4-2: contact pressure along the crack