Fiber/matrix interfacial debonding in a single short-fiber reinforced polymer
composite is investigated using finite elements and a cohesive zone model. The glass
fiber is modeled as an isotropic, linear elastic material. The matrix is modeled as a
linear elastic/elastoplastic material characterized by incremental isotropic hardening.
A cohesive zone model governed by the traction-separation law describes the
fiber/matrix interface. The simulated stress field of the single fiber debonded
and perfectly bonded composites are compared. The results indicate that
the interfacial shear stress decreases to zero on the debonded interface. It
increases to its maximum value over a small processing zone and decreases
exponentially to zero at the fiber midpoint. The debonding length growth in the
plastic model is larger than that in the elastic model at small applied strain
levels, but the trend is reversed as the applied strain level increases. The
influence of factors such as residual thermal stress, interfacial strength, and
fracture toughness on the debonding process of a single fiber composite are
discussed.
Keywords
interfacial debonding, finite element analysis, single
fiber composite, interfacial strength, fracture toughness,
matrix plasticity, residual thermal stress