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Discrete Spring Model for Predicting Delamination Growth in Z-Fiber Reinforced DCB SpecimensBeam theory analysis was applied to predict delamination growth in DCB specimens reinforced in the thickness direction with pultruded pins, known as Z-fibers. The specimen arms were modeled as cantilever beams supported by discrete springs, which were included to represent the pins. A bi-linear, irreversible damage law was used to represent Z-fiber damage, the parameters of which were obtained from previous experiments. Closed-form solutions were developed for specimen compliance and displacements corresponding to Z-fiber row locations. A solution strategy was formulated to predict delamination growth, in which the parent laminate mode I fracture toughness was used as the criterion for delamination growth. The solution procedure was coded into FORTRAN 90, giving a dedicated software tool for performing the delamination prediction. Comparison of analysis results with previous analysis and experiment showed good agreement, yielding an initial verification for the analytical procedure.
Document ID
20040070763
Acquisition Source
Langley Research Center
Document Type
Technical Memorandum (TM)
Authors
Ratcliffe, James G.
(NASA Langley Research Center Hampton, VA, United States)
O'Brien, T. Kevin
(Army Research Lab. Hampton, VA, United States)
Date Acquired
September 7, 2013
Publication Date
January 1, 2004
Subject Category
Metals And Metallic Materials
Report/Patent Number
ARL-TR-3190
NASA/TM-2004-213019
L-19016
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.
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