W. Gu et al., Correlation of fiber pull-out strength and interfacial vibration damping techniques by micromechanical analysis, J MATER SCI, 33(24), 1998, pp. 5731-5737
Adhesion between fiber and matrix in fiber-reinforced polymer composites pl
ays an important role both in controlling mechanical properties and in the
overall performance of composites. This suggests that analytical and experi
mental methods to characterize the interface can be used to predict the mec
hanical performance of the material. To this end, vibration damping techniq
ues have been used as a non-destructive method to evaluate interfacial effe
cts on composites. According to the theory of energy dissipation, the quali
ty of the interfacial adhesion can be evaluated upon separating the predict
ed internal energy dissipation associated with perfect adhesion from the me
asured internal energy dissipation of a composite system; this enables the
quantification of interfacial adhesion. A micromechanics-based model for ev
aluating the adhesion between fiber and matrix from the damping characteris
tic of a cantilever beam was developed that shows an inverse relationship b
etween the damping contributed by the interface and its adhesion strength.
A simple optical system was used to measure the damping factor of unidirect
ional fiber-reinforced-polymer composites. Cantilever beam specimens contai
ning either a single glass fiber or three types of single metallic wires em
bedded in an epoxy resin matrix were tested. A correlation was found betwee
n the measured interfacial adhesion strength directly from microbond pull-o
ut tests and the micromechanics-based calculations from vibration damping e
xperiments. (C) 1998 Kluwer Academic Publishers.