PSI - Issue 68

4

Jaynandan Kumar, Anshul Faye / Structural Integrity Procedia 00 (2024) 000–000

Jaynandan Kumar et al. / Procedia Structural Integrity 68 (2025) 205–211

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1 . 0

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(a) Fine mesh near the void

0 . 0 0 . 2 0 . 4 0 . 6 0 . 8 1 . 0

(b) Mesh with quadrilateral elements.

Fig. 2: Mesh with varying element size

3. Results and discussion

The numerical simulations are performed on the representative model with a void at the center. Contours of the distribution of stresses near the void at a hydrostatic pressure of 50 kPa, in terms of von Mises stress ( σ m ), have been shown in Fig. 3. Simulation is done for di ff erent values of κ . In Fig. 3a, high stresses are concentrated at a point nearly at 60 ◦ . Also, higher distribution of stress is seen along the tangent to the void; this may be due to the contribution of the fiber in that direction. With increasing the value of κ , stresses start distributing on the edge, as shown in Fig. 3b. The stress distribution becomes uniform over the circumference of the void when the value of κ reaches 0.333. This shows the isotropic behaviour of the tissue at κ = 0 . 333. It can also be observed from the Fig. 3 that the ellipticity of the void growth also changes with the distribution of fibers. It changes from circular to elliptical with varying κ from 0.333 to 0. The void growth with hydro-static pressure ( g ) is shown in Fig. 4. Due to the anisotropic behaviour of the tissue, the hoop stretch can change along the circumference of the void; therefore, to analyse the e ff ect of the distribution of fiber on void growth, hoop stretch ( λ h ) on the inner surface of the void at the circumferential location (at x 1 axis near to the location X = 0.001, Y = 0) is considered. The pressure is plotted with the hoop stretch in the figure. The void growth becomes stable with increasing pressure. However, less stretch is observed in the case of ideally aligned fibers ( κ = 0), which show sti ff behaviour.