Композиты и наноструктуры COMPOSITES and NANOSTRUCTURES УДК 621.382(06), 669.294 METHOD FOR COMPUTATIONAL MODELLING OF RESIDUAL STRESSES AND STRESS-INDUCED MANUFACTURING DEFECTS IN VACUUM-INFUSED AUTOMATED PLACEMENT LAMINATES Fedulov B.N.(1) (1) , Safonov A.A.(1) , Nguyen N.Q.(2) KU Leuven, Belgium , Lomov S.V.(2) Skolkovo Institute of Science and Technology, Moscow, Russia (2) Article history Received: 15.11.2015 Accepted: 19.11.2015 В работе рассматриваются трещиностойкость в присутствии технологических дефектов композитов, изготовленных методом автоматизированной выкладки сухих преформ для последующей пропитки связующим материалом методом инфузии. <...> In this paper the investigation on crack resistance of vacuum infused composites with manufacturing defects, manufactured of dry fiber preforms fabricated by automated placement (DFP / ATL) processes is reported. <...> The study discusses the case of possible crack initiation resulting from process thermal influences caused by differences in coefficients of thermal expansion (CTE’s) of matrix and fiber reinforcement, and by shrinkage of matrix. <...> Strain field within a representative volume surrounding a defect is modelled by finite element method. <...> The results of parametric analysis show that under typical conditions of carbon/epoxy composites fabrication a matrix exhibits a sufficient strength to withstand thermal and shrinkage stresses occurring during cure of laminates containing gaps, however, the margin of safety is relatively small and variations in temperature conditions may result in crack formation. <...> Introduction Automated placement (laying) is a high production method of fabricating preforms for subsequent infusion and curing, widely used in composite manufacturing and, first of all, in aviation industry. <...> Automated placement processes offer the benefits of high production capacity combined with a high quality of resulting composites (high precision of fiber arrangement and low porosity). <...> However, automated placement processes may produce defects in fiber arrangement, the most common being tapes overlaps and gaps between tapes. <...> Overlaps and gaps are caused by inaccuracies in tape placement or by curvature of tape placement paths. <...> Gaps may also be produced intentionally in order to increase preform permeability and to speed-up the infusion. <...> Several industrial research organizations (Boeing, NLR, Airbus, Dassault…) and universities (Bristol <...>