Fracture behavior of defective TPO12-graphene: a comprehensive molecular dynamics analysis across temperature and size scale

Abstract

Carbon nanostructures like TPO12-graphene hold immense promise for advanced mechanical applications due to their high strength and Young’s modulus. However, understanding their behavior under varying conditions is crucial for practical implementation. This study investigated the influence of dimensionality, defect density, and temperature on the mechanical properties including ultimate stress, failure strain, Young’s modulus, and fracture toughness of TPO12-graphene using molecular dynamics simulations. In the conducted study, it was observed that tensile strength and failure strain decrease by approximately 27% and 15% respectively when transitioning from a square sheet to a nanoribbon, highlighting significant anisotropy in mechanical response. Furthermore, increasing the defect concentration from 0% to 8% led to an average reduction of 50% in ultimate tensile strength (UTS) and a 42% decrease in fracture toughness at room temperature. Temperature had a pronounced effect, resulting in a 57% decrease in UTS and a 75% reduction in toughness between 1 K and 800 K, while Young’s modulus remained largely unchanged with rising temperature. These findings demonstrate that while defects and temperature independently weaken TPO12-graphene, their combined effect substantially compromises its mechanical integrity, emphasizing the need for careful consideration of these factors in future design and application of these materials.