Qd. Zeng et al., A RANDOM CRITICAL-CORE THEORY OF MICRODAMAGE IN INTERPLY HYBRID COMPOSITES .1. 1ST FAILURE AND HYBRID EFFECT, Composites science and technology, 49(4), 1993, pp. 341-348
This paper presents a statistical analysis for the tensile first failu
re and hybrid effect (which is part of the synergistic effect) of unid
irectional interply hybrid composites. A shear-lag model is applied to
solve the stress redistributions after the breakage of low-elongation
fibers. By applying the random critical core model, the probabilistic
first failure strain of hybrids is evaluated first, and the hybrid ef
fect for strains is consequently evaluated. Reduction of the stress co
ncentration factor and ineffective length of the low-elongation fibers
in hybrids and differences between microdamage mechanisms in hybrids
and single fiber composites provide a theoretical explanation of the h
ybrid effect. The present theoretical results show reasonable agreemen
t with the existing experimental results.