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A Shell/3D Modeling Technique for the Analysis of Delaminated Composite LaminatesA shell/3D modeling technique was developed for which a local solid finite element model is used only in the immediate vicinity of the delamination front. The goal was to combine the accuracy of the full three-dimensional solution with the computational efficiency of a shell finite element model. Multi-point constraints provided a kinematically compatible interface between the local 3D model and the global structural model which has been meshed with shell finite elements. Double Cantilever Beam, End Notched Flexure, and Single Leg Bending specimens were analyzed first using full 3D finite element models to obtain reference solutions. Mixed mode strain energy release rate distributions were computed using the virtual crack closure technique. The analyses were repeated using the shell/3D technique to study the feasibility for pure mode I, mode II and mixed mode I/II cases. Specimens with a unidirectional layup and with a multidirectional layup were simulated. For a local 3D model, extending to a minimum of about three specimen thicknesses on either side of the delamination front, the results were in good agreement with mixed mode strain energy release rates obtained from computations where the entire specimen had been modeled with solid elements. For large built-up composite structures the shell/3D modeling technique offers a great potential for reducing the model size, since only a relatively small section in the vicinity of the delamination front needs to be modeled with solid elements.
Document ID
20000059211
Acquisition Source
Langley Research Center
Document Type
Technical Memorandum (TM)
Authors
Krueger, Ronald
(National Academy of Sciences - National Research Council Hampton, VA United States)
OBrien, T. Kevin
(Army Research Lab. Hampton, VA United States)
Date Acquired
September 7, 2013
Publication Date
June 1, 2000
Subject Category
Composite Materials
Report/Patent Number
L-17977
ARL-TR-2207
NAS 1.15:210287
NASA/TM-2000-210287
Funding Number(s)
PROJECT: RTOP 581-10-21-01
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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