A multi-phase composite with high strength and fracture toughness
is an attractive required characteristic for many structural applications. A multi- phase material can achieve high strength and fracture toughness due to the presence and interaction of various constituent phases with different elastic properties and fracture toughness. The arrangement of stiff and compliant phases, their sizes, fracture toughness, and elastic properties can enhance or control the performance of the material by adjusting the effective elastic modulus and the crack path. In the present work, a phase-field method (PFM) is employed in the finite element framework to study the performance of multi- phase materials by controlling the crack path. PFM does not require the crack path to be tracked as it is represented as smeared damage, making it a suitable methodology for studying crack deflection, branching, merging, and complex cracks in 2D and 3D geometry. The numerical analysis is carried out for three different geometric arrangements of stiff-compliant phases: a diagonal array, a cubic array, and a hexagonal array under plane strain loading conditions. The overall stiffness, displacement to failure, maximum load, and energy absorbed to failure are studied to quantify the material’s performance. The hexagonal array is fascinating as it displayed high strength and energy absorbed to failure, indicating high effective fracture toughness. The mechanical response of the
hexagonal array is investigated for different elastic mismatch ratios, critical energy release rates Gc, and the ratio of stiff-compliant radius to spacing.