PSI - Issue 42

Jaynandan Kumar et al. / Procedia Structural Integrity 42 (2022) 806–812 Jaynandan Kumar, Anshul Faye / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 1. (a) Failure curve in circumferential and longitudinal direction. (b) Curve fitting with bi-axial experimental data (Di Achille et al, 2011); blue data is for circumferential to longitudinal stress ratio and red color data is for longitudinal to circumferential stress ratio.

2.5. RVE preparation and FEM simulation

A Representative Volume Element (RVE) of size (50 µ m × 50 µ m) is generated, in which circular and elliptical calcium particles are randomly distributed with a fixed volume fraction and a fixed range of particles sizes and it is extruded to the thickness of 1 µ m. A python script is used to generate the RVE in ABAQUS. An RVE with 24% volume fraction of particles is shown in Fig.2(a). A mesh is generated which contains tetrahedral linear elements with 6923 nodes and 23307 elements which is shown in Fig. 2 (b). Then Numerical simulation is done for this mesh whose damage initiation is shown in Fig. 3 at the stretch of 1.15 and 1.16. We observe from the Fig 3 that damage is initiating in the RVE where there is less density of particles.

Calcium particles

Anisotropic tissue

50 ¹ m

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Fig. 2. (a) RVE of calcified tissue with 0.24 volume fraction. (b) Mesh of RVE containing 25 % calcium particles with tetrahedral elements