Effect of fiber nonlinear elasticity on the temperature and stress dependence of Young's modulus of continuous fiber composites
Abstract
The effect of the nonlinear elasticity of carbon fibers on the axial Young's modulus of a uniaxial composite is reported. Previous work on a metal matrix composite yielded an equation to predict the axial Young's modulus and its change with temperature. The equation takes into account the thermal strains generated in the fiber and the matrix by the mismatch of thermal expansion, the nonlinear elasticity of the constituents, and the normal effects of temperature and applied stress. Nonlinear elasticity data for pitchbased carbon fibers are used together with data for an aluminum matrix and the predictive equation to calculate Young's modulus. The results are compared with experimental data and the simpler RuleofMixtures (ROM) predictions which neglect the effects of thermally generated strains coupled with nonlinear elasticity. The results display fairly close agreement with measured values of composite modulus, but large differences from the simpler ROM predictions. Although the validity of the predictive equation has not been fully verified, the variation of composite modulus with temperature and applied stress which it predicts is quite significant. Under certain conditions, a composite can be designed with a modulus that is independent of temperature or applied stress. 17 refs.
 Authors:

 Johns Hopkins Univ., Laurel, MD (United States) Akron Univ., OH (United States) Naval Surface Warfare Center, Silver Spring, MD (United States)
 Publication Date:
 OSTI Identifier:
 5554432
 Resource Type:
 Journal Article
 Journal Name:
 SAMPE Quarterly (Society of Aerospace Material and Process Engineers); (United States)
 Additional Journal Information:
 Journal Volume: 24:4; Journal ID: ISSN 00360821
 Country of Publication:
 United States
 Language:
 English
 Subject:
 36 MATERIALS SCIENCE; COMPOSITE MATERIALS; FABRICATION; STRESS ANALYSIS; TEMPERATURE DEPENDENCE; THERMAL EXPANSION; EXPANSION; MATERIALS; 360603*  Materials Properties; 360601  Other Materials Preparation & Manufacture
Citation Formats
Wienhold, P D, Eby, R K, and Liu, J M. Effect of fiber nonlinear elasticity on the temperature and stress dependence of Young's modulus of continuous fiber composites. United States: N. p., 1993.
Web.
Wienhold, P D, Eby, R K, & Liu, J M. Effect of fiber nonlinear elasticity on the temperature and stress dependence of Young's modulus of continuous fiber composites. United States.
Wienhold, P D, Eby, R K, and Liu, J M. Thu .
"Effect of fiber nonlinear elasticity on the temperature and stress dependence of Young's modulus of continuous fiber composites". United States.
@article{osti_5554432,
title = {Effect of fiber nonlinear elasticity on the temperature and stress dependence of Young's modulus of continuous fiber composites},
author = {Wienhold, P D and Eby, R K and Liu, J M},
abstractNote = {The effect of the nonlinear elasticity of carbon fibers on the axial Young's modulus of a uniaxial composite is reported. Previous work on a metal matrix composite yielded an equation to predict the axial Young's modulus and its change with temperature. The equation takes into account the thermal strains generated in the fiber and the matrix by the mismatch of thermal expansion, the nonlinear elasticity of the constituents, and the normal effects of temperature and applied stress. Nonlinear elasticity data for pitchbased carbon fibers are used together with data for an aluminum matrix and the predictive equation to calculate Young's modulus. The results are compared with experimental data and the simpler RuleofMixtures (ROM) predictions which neglect the effects of thermally generated strains coupled with nonlinear elasticity. The results display fairly close agreement with measured values of composite modulus, but large differences from the simpler ROM predictions. Although the validity of the predictive equation has not been fully verified, the variation of composite modulus with temperature and applied stress which it predicts is quite significant. Under certain conditions, a composite can be designed with a modulus that is independent of temperature or applied stress. 17 refs.},
doi = {},
journal = {SAMPE Quarterly (Society of Aerospace Material and Process Engineers); (United States)},
issn = {00360821},
number = ,
volume = 24:4,
place = {United States},
year = {1993},
month = {7}
}