Effect of Angle, Temperature and Vacancy Defects on Mechanical Properties of PSI-Graphene

• Main Authors: Lu Xie, Tingwei Sun, Chenwei He, Haojie An, Qin Qin, Qing Peng
• Format: Article
• Language: English
• Published: MDPI AG 2019-05-01
• Series: Crystals
• Subjects: PSI-graphene; mechanical properties; stretching direction; fracture morphology; vacancy defects
• Online Access: https://www.mdpi.com/2073-4352/9/5/238

The PSI-graphene, a two-dimensional structure, was a novel carbon allotrope. In this paper, based on molecular dynamics simulation, the effects of stretching direction, temperature and vacancy defects on the mechanical properties of PSI-graphene were studied. We found that when PSI-graphene was stretched along 0° and 90° at 300 K, the ultimate strength reached a maximum of about 65 GPa. And when stretched along 54.2° and 155.2° at 300 K, the Young’s modulus had peaks, which were 1105 GPa and 2082 GPa, respectively. In addition, when the temperature was raised from 300 K to 900 K, the ultimate strength in all directions was reduced. The fracture morphology of PSI-graphene stretched at different angles was also shown in the text. In addition, the number of points removed from PSI-graphene sheet also seriously affected the tensile properties of the material. It was found that, compared with graphene, PSI-graphene didn’t have the negative Poisson’s ratio phenomenon when it was stretched along the direction of 0°, 11.2°, 24.8° and 34.7°. Our results provided a reference for studying the multi-angle stretching of other carbon structures at various temperatures.