In the present study, the effect of specimen sizes on the residual stresses inherited during manufacturing of IM7/8552-1 carbon-epoxy composites with concentrator was investigated. The first part of the research is devoted to the understanding of residual stresses in regular specimens during cure cycle depending on different ply and laminate thickness. To describe the behavior of the composite material during the manufacturing process - including processes of formation, polymerization, development of residual strains and stresses the special user subroutine was developed and implemented into ABAQUS FEM software. The second part of this paper concerns the study of the «hole-size effect» on the value of residual stress in composites with concentrator. The most important variables have been identified as notch size, and ply and laminate thickness. These have been scaled in two ways: independently and simultaneously. Obtained by modelling values for stress components are essential and cannot be ignored in consequent structural analysis.