PSI - Issue 32

L.V. Stepanova et al. / Procedia Structural Integrity 32 (2021) 261–272 Author name / StructuralIntegrity Procedia 00 (2019) 000–000

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minimization of the whole system that is followed by the dynamics equilibration to achieve a stress – freestate and temperature of 10 K. NPT ensemble is used for the dynamics equilibration. Next, displacement-controlled simulations are performed by applying a uniaxial displacement controlled in the direction 2 x at a constant strain-rate 1 2.0 3 e s ε − = −  for mode I loading. A micro-canonical (NVE) ensemble is used for the MD simulations. The crack is created by deleting one of atoms and the crack length is 72,3A what is equal to 10% of the plate width. The total number of atoms is 719820. The results of molecular dynamics simulations of the tensile loading of the central crack are shown in figs. 1-6. Figure 1 shows the distributions of the stress component 11 σ at 5000 (left) and 10000 (right) steps of simulation respectively.Figure 2 shows the distributions of the stress component 11 σ at 15000 (left) and 20000 (right) steps of simulation respectively.

11 σ at 5000 (left)and 10000 (right) steps of simulation

Fig. 1. Distributions of

Fig. 2. Distributions of 11 σ at 15000 (left) and 20000 (right) steps of simulation. Figures 3 and 4 show the distributions of the stress component 22 σ at 5000, 10000, 15000 and 20000 steps of simulation respectively.Figures 5 and 6 show the distributions of the stress component 12 σ at 5000, 10000, 15000 and 20000 steps of simulation respectively. Results of molecular dynamics modelling of mixed mode loading are shown in figs. 7-12. The regions and the points that are chosen for the determination of the coefficients of the Williams series expansion are shown in fig.13.