Investigating the effect of special nanopore shapes on Graphene mechanical properties using a computationally efficient atomic finite element model

To investigate the influence of special nanopore shapes on the mechanical properties of graphene at the atomic scale, a suitable nonlinear atomic-scale finite element model (AFEM) is developed based on the Stillinger Weber interatomic potential (SW). The discrete element created is an atomic finite element consisting of ten atoms, which can capture the dominant local and non-local atomistic interactions dictated by the present interatomic potential. Furthermore, the anterior works demonstrated the simplicity and the accuracy of the SW potential compared to the well-known interatomic potentials used in AFEM for predicting the elastic and fracture properties of graphene. The accuracy of the present model is checked by studying the graphene mechanical properties under the tensile and the shear tests, the comparison between our results and those reported in the literature showed a better agreement. The effect of diamond, hexagonal and rectangular nanopores, as well as their orientations on the elastic and fracture properties of graphene under the tensile and shear tests is also studied. Notably, previous literature lacks a comprehensive study on the shear properties of graphene under nanopore shapes. Our results show that the graphene’s mechanical properties are more affected by the nanopores oriented perpendicular to the direction of the applied load. Particularly, the nanopores with elongated sharp tip edges, such as the diamond shape, have the greatest impact on graphene's mechanical response. The results show the ability of the present AFEM to investigate the mechanical behavior of graphene in the presence of various nanopore shapes with high precision at reduced computational time compared to its counterparts. Additionally, it offers simplicity and efficiency in studying large-scale systems.