Abstract
This article proposes an elastic-plastic damage model that combines micromechanical modeling with continuum damage mechanics to predict the stress-strain response of injection-molded long-fiber thermoplastics. The model accounts for distributions of orientation and length of elastic fibers embedded in a thermoplastic matrix whose behavior is elastic-plastic and damageable. The elastic-plastic damage behavior of the matrix is described by the modified Ramberg-Osgood relation and the 3D damage model in deformation assuming isotropic hardening. Fiber/matrix debonding is accounted for using a parameter that governs the fiber/matrix interface compliance. A linear relationship between this parameter and the matrix damage variable is assumed. First, the elastic-plastic damage behavior of the reference aligned fiber composite containing the same fiber volume fraction and length distribution as the actual composite is computed using an incremental Eshelby-Mori-Tanaka mean field approach. The incremental response of the latter is then obtained from the solution for the aligned-fiber composite by averaging over all fiber orientations. The model is validated against the experimental stress-strain results obtained for long-glass-fiber/polypropylene specimens.
Original language | English |
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Pages (from-to) | 691-725 |
Number of pages | 35 |
Journal | International Journal of Damage Mechanics |
Volume | 19 |
Issue number | 6 |
DOIs | |
State | Published - Aug 2010 |
Keywords
- continuum damage
- elastic-plastic
- failure
- fiber
- fiber length distribution
- fiber orientation
- injection molding
- long-fiber thermoplastics
- matrix cracking
- matrix debonding
- strength