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U.S. Department of Energy
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Analysis of cracks in nonlinear fiber-composite materials

Thesis/Dissertation ·
OSTI ID:5398397
The effect of effective material nonlinear properties of fiber composites on crack behavior is studied. Three-dimensional nonlinear constitutive equations are established, based on both complementary energy density and deformation plasticity approaches. A system of highly non-linear, coupled governing partial differential equations are derived for a generalized plane-deformation problem of the composites. Orders of stress singularity near cracks in both 0{degrees}- and 90{degrees}- fiber composites are obtained. A dimensional analysis based on conservation integrals in nonlinear mechanics is used first to achieve this goal. Also, the stress singularities and asymptotic stress fields of the fiber composites are obtained by directly solving the governing partial differential equations. Detailed solutions for complete stress fields and associated near-field stress amplitudes in the cracked nonlinear fiber composites under pure single loading modes and mixed-mode loading are determined by employing an advanced finite-element method with surrounding nonlinear elements and crack-tip singular element formulations.
Research Organization:
Illinois Univ., Urbana, IL (United States)
OSTI ID:
5398397
Country of Publication:
United States
Language:
English