composite, residual stress, defect, energy release rate.

In the present study, the effect of presence of residual stresses inherited during manufacturing on delamination defect in carbon-epoxy composite specimen is investigated. The research is devoted to understanding of strain-stress state in regular specimens near defect zone during cure cycle and after free edge cut depending on crack length. To describe the behavior of the composite material during manufacturing process- including processes of formation, polymerization, development of residual stresses and strains, the special user subroutine was developed and implemented in ABAQUS FEM software. The history of energy release rates under mode I, II (GIc, GIIc) where analyzed over time during process of polymerization and free edge cut.

A slight increase in the GI and GII values at the crack tip during polymerization and a multiple excess of these values after a mechanical cut is shown. Obtained by modelling values for stress components are essential and cannot be ignored in consequent structural analysis. The results of the study can be applied for prediction of residual stresses in composite structure by means of simulation and further understanding the nature of fracture of composites.

Bondarchuk Daria Alexandrovna, PhD student, Lomonosov Moscow State University,GSP-1, Leninskie Gory, Moscow, 119991, Russian Federation.

Fedulov Boris Nikitovich, D.Sc. in Physical and Mathematical Sciences, Lomonosov Moscow State University,GSP-1, Leninskie Gory, Moscow, 119991, Russian Federation.

Lomakin Evgenii Viktorovich, D.Sc. in Physical and Mathematical Sciences, Lomonosov Moscow State University,GSP-1, Leninskie Gory, Moscow, 119991, Russian Federation.