Print Email Facebook Twitter Fatigue life and damage tolerance of postbuckled composite stiffened structures with indentation damage Title Fatigue life and damage tolerance of postbuckled composite stiffened structures with indentation damage Author Davila, C.G. (NASA Langley Research Center) Bisagni, C. (TU Delft Aerospace Structures & Computational Mechanics) Date 2018-03-01 Abstract The fatigue life and damage tolerance of composite stiffened panels with indentation damage are investigated experimentally using single-stringer compression specimens. The indentation damage was induced to one of the two flanges of the stringer of every panel. The advantages of indentation compared to impact are the simplicity of application, less dependence on boundary conditions, better controllability, and repeatability of the imparted damage. The tests were conducted using advanced instrumentation, including digital image correlation, passive thermography, and in situ ultrasonic scanning. Specimens with initial indentation damage ranging between 32 and 56 mm in length were tested quasi-statically and in fatigue, and the effects of cyclic load amplitude and damage size were studied. A means of comparison of the damage propagation rates and collapse loads based on a stress intensity measure and the Paris law is proposed. The stress intensity measure provides the means to compare the collapse loads of specimens with different damage types and damage sizes, while the Paris law is used to compare the damage propagation rates in specimens subjected to different cyclic loads. This approach enables a comparison of different tests and the potential identification of the effects that influence the fatigue lives and damage tolerance of postbuckled structures with defects. Subject Composite structuresdamage tolerancefatigueindentation damagepostbucklingtests To reference this document use: http://resolver.tudelft.nl/uuid:c5c9bb98-29f2-4c5d-9514-e2e982cb6f30 DOI https://doi.org/10.1177/0021998317715785 ISSN 0021-9983 Source Journal of Composite Materials, 52 (7), 931-943 Part of collection Institutional Repository Document type journal article Rights © 2018 C.G. Davila, C. Bisagni Files PDF 0021998317715785.pdf 1.68 MB Close viewer /islandora/object/uuid:c5c9bb98-29f2-4c5d-9514-e2e982cb6f30/datastream/OBJ/view