PSI - Issue 28

D.A. Bondarchuk et al. / Procedia Structural Integrity 28 (2020) 743–751 Author name / Structural Integrity Procedia 00 (2019) 000–000

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Fig. 5. Stress distribution (Pa) in a sample with [0°/90°] 12 layup and a crack 6 mm long after polymerization and after cutting (on a scale of displacements x20).

Table 1. Mode I, Mode II and Mode III critical energy release rates. G IC [N/m] G IIC [N/m]

G IIIC [N/m] 790…2590

280…293.44

790…2590

The values of G I and G II for the specimen with [0°/90°] 12 layup depending on crack length is demonstrated in Fig. 6 and Fig.7 after polymerization and after cutout. The values of energy release rates under Mode I and Mode II after cure for modelled crack length are significantly less than the critical values. It means that the delamination defect-initial crack doesn’t grow due to manufacturing reasons and residual stresses have no effect.

Fig. 6. G I after cure (a) and G I after cut (b) of sample depending on crack length.