Fatigue failure poses a significant challenge in the design and
reliability of structural components as the failure occurs at a load below the
monotonic strength of the material. A multi-phase composite embedded with a
stiff and compliant particle has a complex failure mechanism because of its
intricate internal structure. Moreover, the fatigue process gradually reduces the
material stiffness and the fracture toughness of the material before further
rupturing or catastrophic failure. The interaction of stiff and compliant
phases/particles, as well as with the crack, can be tuned to enhance the
performance of the multi-phase composite. In the present work, a phase-field
method (PFM) is employed in the finite element framework to study the fracture
mechanism of multi-phase composite. PFM can naturally simulate complex
fatigue fracture behavior in multi-phase composites. The numerical analysis is
carried out to investigate the fatigue fracture mechanism and its effect on the
performance of the multi-phase composite subjected to cyclic loading. The
effect of particle elastic property, fracture toughness, and size on the fracture
mechanism and the resulting life of the composite is studied. The crack is more
distributed with the reduction in stiffness of the compliant particles, enhancing
the life.