PSI - Issue 18

D.A. Bondarchuk et al. / Procedia Structural Integrity 18 (2019) 353–367 D.A. Bondarchuk, B.N.Fedulov, A.N. Fedorenko / Structural Integrity Procedia 00 (2019) 000 – 000

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2. Problem statement As mentioned before, the AS4/8552-1 carbon-epoxy composite with [0 0 /90 0 ] The sample and its geometrical dimensions are shown in Fig. 1.

12 lay-up was considered for analysis.

3.12 mm

25 mm

Fig. 1. Sample of the AS4/8552-1 carbon-epoxy composite with [0 0 /90 0 ]

12 lay-up.

The problem of free edge stress analysis consists of two stages. The first one is the modeling of the curing process and formation of residual stresses. The second stage is an appearing of free edge in the middle of the specimen. To describe the behavior of the material during polymerization, a special material model, which takes into account changes in the physical and mechanical properties over time and depending on temperature was used by Baran et al. (2016), Johnston (2001), Bogetti and Gillespie (1992). For temperature initial and boundary conditions, the cure cycle recommended by manufacturer (Fig. 2) was used. The parameters of the material were also taken from epoxy matrix product datasheet (2018), Hexply 8552 Material properties database (2009) works of Ersoy et al. (2010), Boyard N. (2016) and provided in Table 1 Appendix A.

Fig. 2. Cure cycle.