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

• Published in: Crystals (Basel) Vol. 9; no. 5; p. 238
• Main Authors: Xie, Lu, Sun, Tingwei, He, Chenwei, An, Haojie, Qin, Qin, Peng, Qing
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.05.2019
• Subjects: Allotropy; Boundary conditions; Carbon; Composite materials; Conductivity; Defects; fracture morphology; Graphene; Heat conductivity; Mechanical properties; Modulus of elasticity; Molecular dynamics; Morphology; Poisson's ratio; PSI-graphene; Simulation; Stress-strain curves; Stretching; stretching direction; Symmetry; Tensile properties; Ultimate tensile strength; Vacancies; vacancy defects
• ISSN: 2073-4352; 2073-4352
• DOI: 10.3390/cryst9050238

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.