skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Mechanical properties of hybrid (medium modulus graphite, Thornel P-55 Kevlar/Epoxy) composites

Abstract

This paper treats the mechanical behavior of hybrid (Thornel P-55-Kevlar/Epoxy) composites under ambient conditions and under hostile environments. Interply (core/shell) and intraply tubes (5.75'' I.D.) were filament wound and NOL rings were machined from them. Apparently modulus and apparent strength were measured using the split D (ASTM D2290) test. The influence of boiling water exposure (2 hrs and 24 hrs) on short beam shear strength, apparent modulus, and apparent strength was also evaluated at room temperature and the fracture toughness for above configurations was measured at room temperature. Scanning electron microscopy was used to examine failure modes. 6 references, 4 figures, 3 tables.

Authors:
;
Publication Date:
Research Org.:
B.F. Goodrich R and D Center, Brecksville, OH
OSTI Identifier:
6715555
Resource Type:
Journal Article
Resource Relation:
Journal Name: SAMPE Q.; (United States); Journal Volume: 18:2
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; COMPOSITE MATERIALS; MECHANICAL PROPERTIES; ARAMIDS; CARBON FIBERS; EPOXIDES; FAILURES; GLASS; FIBERS; MATERIALS; ORGANIC COMPOUNDS; ORGANIC OXYGEN COMPOUNDS; PETROCHEMICALS; PETROLEUM PRODUCTS; PLASTICS; SYNTHETIC MATERIALS 360603* -- Materials-- Properties

Citation Formats

Raghava, R.S., and Peters, S.T. Mechanical properties of hybrid (medium modulus graphite, Thornel P-55 Kevlar/Epoxy) composites. United States: N. p., 1987. Web.
Raghava, R.S., & Peters, S.T. Mechanical properties of hybrid (medium modulus graphite, Thornel P-55 Kevlar/Epoxy) composites. United States.
Raghava, R.S., and Peters, S.T. 1987. "Mechanical properties of hybrid (medium modulus graphite, Thornel P-55 Kevlar/Epoxy) composites". United States. doi:.
@article{osti_6715555,
title = {Mechanical properties of hybrid (medium modulus graphite, Thornel P-55 Kevlar/Epoxy) composites},
author = {Raghava, R.S. and Peters, S.T.},
abstractNote = {This paper treats the mechanical behavior of hybrid (Thornel P-55-Kevlar/Epoxy) composites under ambient conditions and under hostile environments. Interply (core/shell) and intraply tubes (5.75'' I.D.) were filament wound and NOL rings were machined from them. Apparently modulus and apparent strength were measured using the split D (ASTM D2290) test. The influence of boiling water exposure (2 hrs and 24 hrs) on short beam shear strength, apparent modulus, and apparent strength was also evaluated at room temperature and the fracture toughness for above configurations was measured at room temperature. Scanning electron microscopy was used to examine failure modes. 6 references, 4 figures, 3 tables.},
doi = {},
journal = {SAMPE Q.; (United States)},
number = ,
volume = 18:2,
place = {United States},
year = 1987,
month = 1
}
  • New advanced space systems will require increased dimensional stability to allow fabrication and use of large space structures and dimensionally critical components. Minimization of dryout shrinkage in the space environment will be critical to stability enhancements. A program to evaluate new low moisture absorption resin systems was initiated to obtain mechanical and moisture absorption data to aid in the selection of matrix resin systems for future structures. This paper describes the mechanical properties and moisture absorption of low coefficient of thermal expansion quasi-isotropic laminates made from these systems.
  • The response of Kevlar and graphite/epoxy composites subjected to simulated nuclear or laser thermal loads was measured. A solar furnace was used to radiantly heat samples at flux rates of up to 55 cal/sq cm per sec and total fluences of approximately 100 cal/sq cm. An iterative numerical technique was used to estimate the thermophysical properties of the materials by matching observed temperature-time histories with analytical predictions. Comparison of results obtained during this program with previously published data suggests that free stream velocity, which affects smoke blockage and char layer removal, is a critical design parameter. 8 references.
  • The physical and mechanical properties of 8-ply graphite/epoxy laminates subjected to three cure cycles with varying heat-up rates are studied. Reverse-phase liquid and IR chromatography, differential scanning calorimetry, and rheological measurements are utilized to examine changes in reaction enthalpy, viscosity, and chemical structure. Glass transition temperature, tensile strength, and fracture toughness are measured; fiber volume, resin, and void content and decomposition profiles are evaluated with texture and thermogravimetric analyses. The data reveal that slower heat-up rates produce larger reaction enthalpies and composites with higher resin content; however, faster heat-up rates yield composites with lower resin content and higher glass transitionmore » temperatures. It is observed that the mechanical properties are unaffected by postcuring. 32 references.« less
  • The deformation and fracture behaviors of hybrid-particulate epoxy composites have been examined. These materials were based on a DGEBA/DDA matrix with various volume fractions of glass beads and different rubber contents. Young's modulus, yield stress, dynamic mechanical spectra, and fracture energy have been determined at room temperature. The Kerner model fits well the Young's modulus for the hybrid complexes with various glass bead contents. The analysis of the relaxation peak recorded from viscoelastic measurements allow us to discuss the influence of the introduction of the glass beads on the mobility of macromolecular chains and the characteristics of the rubber-separated phase.more » The fracture energy displays a strong improvement and synergism effect due to the presence of both kinds of particles. The toughening mechanisms were discussed.« less
  • The effects of a high molecular weight polymeric interlayer between the graphite fibers and epoxy matrix of a graphite/epoxy composite on the composite mechanical properties were studied. Thickness, modulus of the interlayer and the bonding between the interlayer and the epoxy matrix were the three major parameters examined. A uniform thickness, 10/sup 5/ g/mole molecular weight, acrylonitrile/methyl acrylate copolymer coating was applied onto the graphite fiber surface through a batch electro-copolymerization technique. The bonding between the interlayer and the epoxy matrix was improved by gradually adding acrylic acid in the last stage of electropolymerization process. 19 references, 8 figures.