PSI - Issue 33

9

Derouiche Sami et al. / Procedia Structural Integrity 33 (2021) 996–1006 Author name / Structural Integrity Procedia 00 (2019) 000–000

1004

Fig. 3. An orthotropic center edge cracked plate with (a is the crack length, E 1 and E 2 are the Young’s modulus) The mechanical and geometrical symmetry in this problem allow the discretisation of a half of the structure. Using the mixed finite element, presented in the previous section, to compute the energy release rates for different angles that varies from β=0° to β=90°. The plate is discretized into 98 elements with 281 nodes and the relative integration domain size, r/a, is about 10 -6 to 10 -13 .

Table 1. Mechanical and geometrical properties. Property

Value

Young’s modulus E 1 (MPa) Young’s modulus E 2 (MPa)

570

16300 0.0178

Poisson’s ratio ν 12

Shear modulus G (MPa) Traction loading (MPa)

680

10

Crack length (mm) Plate length (mm) Plate width (mm)

1 8 4

0,00 20,00 40,00 60,00 80,00 100,00

SDP Analytic

ERR (Nm/m²)

0

20

40

60

80

100

Angle (°)

Fig. 4. Energy release rate provided from the stiffness derivative procedure and compared side by side with the analytical ones.