A dual homogenization and finite-element study on the in-plane local and global behavior of a nonlinear coated fiber composite
✍ Scribed by S.F. Zheng; K. Ding; M. Denda; G.J. Weng
- Publisher
- Elsevier Science
- Year
- 2000
- Tongue
- English
- Weight
- 849 KB
- Volume
- 183
- Category
- Article
- ISSN
- 0045-7825
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✦ Synopsis
In order to uncover the in¯uence of localized deformation in the soft interphase layer on the global elastoplastic behavior of a ®ber-reinforced composite, a dual homogenization and ®nite-element study is presented in this paper. The homogenization approach makes use of the concept of secant moduli and an energy-based eective stress which is evaluated by a ®eld ¯uctuation method. In the ®nite-element analysis NASTRAN was used, with the triangular elements carefully constructed in the unit cell to deliver the local stress and strain ®elds of the constituent phases. These dual investigations are complementary in that the homogenization theory could readily provide the overall stress±strain curves of the composite whereas the ®nite-element analysis could give the local stress ®elds which are important to the onset of damage or crack initiation. The results of ®nite-element method (FEM) could also be used to assess the accuracy of the homogenization theory. Detailed comparisons between the two have indicated that the homogenization theory is suciently accurate. The propagation of plastic zone in both ductile phases are also vividly demonstrated. In addition, the soft interphase is found to be a region of high strain concentration, rendering the entire system with a lower elastoplastic strength as compared to an ordinary 2-phase composite.