Curved beam strength and toughness of thin ply cfrp non crimp fabric laminates

Arca, Miray
Papila, Melih
Çöker, Demirkan
Carbon fiber reinforced plastics are most widely used composite materials in aerospace and wind turbine industries. Their superior in plane properties with light weight structures and also ability to change and design the structure and form make composites preferable to metallic materials. Composites are applied to the primary load carrying members with complex and curved geometries with the new manufacturing techniques. On the other hand, failure mechanisms of composites are different and complicated than the metallic structures. Out of plane properties of composites are not as good as in plane properties, unbalanced properties of reinforcement and matrix and radial geometry of the curved part creates weakness through the thickness direction leading to delamination failure. In this study effect of novel material-thin ply non crimp fabric laminates on delamination resistance of carbon fiber reinforced plastics composites are presented. For this purpose standard test methods are carried out, fracture toughnesses and behavior of laminates under moment loading are obtained experimentally. The dynamic delamination propagation and failure sequences are captured using Photron© Fastcam SA5 ultra high speed system. Changing the material type from unidirectional to thin-ply non-crimp fabric material increased the mode I, mode II fracture toughness and curved beam strength of the laminates. It is observed that the manufacturing defects are the potential failure initiation sides.
8th Ankara International Aerospace Conference, 10 - 12 September 2015


Sonat, Emine Evren; Özerinç, Sezer; Department of Mechanical Engineering (2021-12-10)
Carbon fiber reinforced polymer (CFRP) composites are increasingly used in the aerospace industry due to their high specific strength compared to conventional metallic materials. However, a significant shortcoming of these composites is their increased susceptibility to damage. Structural repair is a common method to restore the load-carrying capacity of a damaged part when the damage size exceeds the pre-defined tolerances. Scarf and stepped bonded repair methods are the primary choice for cases that requi...
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Dynamic failure of curved CFRP composite laminates under quasi static loading
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In aerospace and wind energy industries, new advances in composite manufacturing technology and high demand for lightweight structures are fostering the use of composite laminates in a wide variety of shapes as primary load carrying elements. However, once a moderately thick laminate takes highly curved shape, such as an L-shape, Interlaminar Normal Stresses (ILNS) are induced together with typical Interlaminar Shear Stresses (ILSS) on the interfaces between the laminas. The development of ILNS promotes mod...
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High mechanical properties and light weight structures of composite materials and advances in manufacturing processes have increased the use of composite materials in the aerospace and wind energy industries as a primary load carrying structures in complex shapes. However, use of composite materials in complex geometries such as L-shaped laminates creates weakness at the radius which causes delamination. Carbon nanotubes (CNTs) is preferred as a toughening materials in composite matrices due to their high m...
Citation Formats
M. Arca, M. Papila, and D. Çöker, “Curved beam strength and toughness of thin ply cfrp non crimp fabric laminates,” presented at the 8th Ankara International Aerospace Conference, 10 - 12 September 2015, Ankara, Turkey, 2015, Accessed: 00, 2021. [Online]. Available: