Molecular dynamics insights into the mechanical behavior of Kagome graphene: size, strain-rate, temperature, and defect effects

Kagome graphene is a low-density sp²-bonded carbon allotrope in which triangular units and Kagome-like pores form a load-bearing network distinct from graphene's honeycomb lattice. Although its flat-band physics and tensile wrinkling have been discussed, its reliability under thermal, rate, and defect conditions remains unclear. Here, classical molecular dynamics simulations are used to identify how Kagome topology controls stiffness, strength, and fracture. The structure is benchmarked against reported first-principles calculated geometry and a same-protocol graphene control; the AIREBO limitations for this strained network are stated. The model-size analysis is treated as a periodic-cell convergence test, leading to a 32.2 × 32.2 nm cell with room-temperature Young's moduli of 318.08 and 317.70 GPa along the c₂-parallel x and c₁-parallel y directions, and ultimate strengths of 23.31 and 27.21 GPa. Kagome graphene shows pronounced rate-dependent failure, with strain-rate-sensitivity exponents of 0.10265 and 0.07497 in x and y. Temperature is more damaging: increasing from 300 to 900 K reduces strength by 72.0–75.1% and strain-energy density to fracture by 90.1–93.2%. Defects constructed at the same nominal geometric scale show that stiffness loss is governed by removed load-bearing area and ligament continuity, whereas strength and failure strain are controlled by edge orientation and crack-like stress concentration. These mechanisms provide design rules for Kagome-graphene nanodevices and motivate future first-principles or machine-learning-potential fracture studies.