Uniaxial cyclic tests were performed on composite IM7/5260 and matrix Narmco 5260 specimens at 24°C (75°F), 107°C (225°F) and 149°C (300°F). Based on the test results, a constitutive model was obtained to describe matrix cyclic plasticity. Subsequently, by assuming linear elastic behavior for fiber IM7 and perfect bonding between fiber and matrix, a simple micromechanical model was used to predict the cyclic behavior of the composite. For initial loading, model predictions agree with experimental results very well. For the subsequent cyclic loading, the model underestimates the average stiffness over a cycle, and the matrix properties require adjustments to yield satisfactory results.
1. Kenaga, D., J. F. Doyle and C. T. Sun. 1987. "The Characterization of Boron/Aluminum Composite in the Nonlinear Range as an Orthotropic Elastic-Plastic Material,"J. of Composite Materials, 21:516-531.
2.
2. Sun, C. T. and J. L. Chen. 1989. "A Simple Flow Rule for Characterizing Nonlinear Behavior of Fiber Composites,"J. of Composite Materials, 23:1009-1020.
3.
3. Dvorak, G. J. and Y. A. Bahei-El-Din. 1982. "Plasticity Analysis of Fibrous Composites,"J. of Applied Mechanics, 49:327-335.
4.
4. Hopkins, D. A. and C. C. Chamis. 1985. "A Unique Set of Micromechanics Equations for High Temperature Metal Matrix Composites," NASA TM 87154, prepared for The First Symposium on Testing Technology of Metal Matrix Composites sponsored by ASTM, Nashville, TN.
5.
5. Aboudi, J. A.1988. "A Continuum Theory for Fiber-Reinforced Elastic-Viscoplastic Composites,"Int. J of Engineering Science, 20:177-196.
6.
6. Robertson, D. D. and S. Mall. 1993. "Micromechanical Relations for Fiber-Reinforced Composites Using the Free Transverse Shear Approach,"J. of Composites Technology and Research, 15:181-192.
7.
7. Sun, C. T. and J. L. Chen. 1991. "A Micromechanical Model for Plastic Behavior of Fibrous Composites,"Composites Science and Technology, 40:115-129.
8.
8. Gates, T. S., J. L. Chen and C. T. Sun. 1994. "Micromechanical Characterization of Nonlinear Behavior of Advanced Polymer Matrix Composites," ASTM 12th Composite Materials: Testing and Design.
9.
9. Dafalias, Y. F. and E. P. Popov. 1975. "A Model of Nonlinearly Hardening Materials for Complex Loading,"Acta Mechanica, 21:173-192.
10.
10. Sun, C. T. and Y. Rui. "A Composite Model for AS4/PEEK Thermoplastic Composite under Cyclic Loading,"Proc. of Sixth Annual Technical Conference of American Society for Composites, Al-bany, NY, 1064-1079.
11.
11. Voyiadjis, G. Z. and G. Thiagarajan. 1996. "A Cyclic Anisotropic-Plasticity Model for Metal Matrix Composites,"International Journal of Plasticity, 12:69-91.
12.
12. Rogacki, J. R. and M. E. Tuttle. 1992. "An Investigation of the Thermoviscoplastic Behavior of a Metal Matrix Composite at Elevated Temperatures," NASA Contractor Report 189706.
