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Mechanical properties of triaxially braided composites: Experimental and analytical resultsThe unnotched tensile properties of 2-D triaxial braid reinforced composites from both an experimental and an analytical viewpoint are studied. The materials are graphite fibers in an epoxy matrix. Three different reinforcing fiber architectures were considered. Specimens were cut from resin transfer molded (RTM) composite panels made from each braid. There were considerable differences in the observed elastic constants from different size strain gage and extensometer reading. Larger strain gages gave more consistent results and correlated better with the extensometer reading. Experimental strains correlated reasonably well with analytical predictions in the longitudinal, 0 degrees, fiber direction but not in the transverse direction. Tensile strength results were not always predictable even in reinforcing directions. Minor changes in braid geometry led to disproportionate strength variations. The unit cell structure of the triaxial braid was discussed with the assistance of computer analysis of the microgeometry. Photomicrographs of braid geometry were used to improve upon the computer graphics representations of unit cells. These unit cells were used to predict the elastic moduli with various degrees of sophistication. The simple and the complex analyses were generally in agreement but none adequately matched the experimental results for all the braids.
Document ID
19950022002
Acquisition Source
Legacy CDMS
Document Type
Conference Paper
Authors
Masters, John E. (Lockheed Engineering and Sciences Co. Hampton, VA, United States)
Foye, Raymond L. (North Carolina Agricultural and Technical State Univ. Greensboro, NC., United States)
Pastore, Christopher M. (North Carolina Univ. Raleigh, NC., United States)
Gowayed, Yasser A. (North Carolina Univ. Raleigh, NC., United States)
Date Acquired
September 6, 2013
Publication Date
September 1, 1992
Publication Information
Publication: FAA, Ninth DOD(NASA)FAA Conference on Fibrous Composites in Structural Design, Volume 1
Subject Category
Composite Materials
Accession Number
95N28423
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

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IDRelationTitle19950021845Collected WorksNinth DOD/NASA/FAA Conference on Fibrous Composites in Structural Design, volume 3
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