Study of crack propagation in multi-phase composites embedded with both stiff and compliant particles using phase field method

Abstract

Abstract Crack propagation in two-phase particle-reinforced composites is extensively studied using
the phase field method. Typically, the particle either has a higher stiffness(stiff) or a lower
stiffness(compliant) than the matrix. However, the crack propagation in multi-phase composites
with both the stiff and compliant particles is not yet understood well. In this work, we report
on the crack propagation characteristics and the resulting enhanced effective fracture toughness
in multi-phase composite materials with both stiff and compliant particles using the phase filed
method. Three different geometric arrangements of particles are considered: a diagonal array,
a cubic array, and a honeycomb array. The honeycomb configuration had the best combination
of strength and effective fracture toughness. We show that apart from the local geometric
arrangement of the individual particles, the ratio of the stiffness of the individual particles is
an important factor in crack propagation. Furthermore, we show that the ratio of the critical
energy release rate of the individual particles can be tuned to increase the effective fracture
toughness.