The effect of electric charge on the mechanical properties of graphene under tensile loading is investigated by using molecular dynamics method.A modified atomistic moment method based on the classical electrostatics ...The effect of electric charge on the mechanical properties of graphene under tensile loading is investigated by using molecular dynamics method.A modified atomistic moment method based on the classical electrostatics theory is proposed to obtain the distribution of extra charges induced by an external electric field and net electric charges stored in graphene.The electrostatic interactions between charged atoms are calculated using the coulomb law.The results show that the Young's modulus and the critical fracture stress under uniaxial tension decrease with the increase of electric potential and net charges on graphene.The failure of graphene induced by electric charges is found to be controlled by charge level.The results indicate that the carbon-carbon bonds at the edge of graphene will break first.展开更多
The effect of electrostatic tractions on the fracture behavior of a dielectric material under mechanical and/or electric loading is analyzed,by studying a pre-cracked parallel-plate capacitor,and illustrated by plots....The effect of electrostatic tractions on the fracture behavior of a dielectric material under mechanical and/or electric loading is analyzed,by studying a pre-cracked parallel-plate capacitor,and illustrated by plots.The results indicate that electrostatic tractions on the electrodes compress the material in front of the crack tip,while electrostatic tractions on the crack faces have the tendency to close the crack and stretch the material behind the crack tip.Mechanical load is the driving force to propagate the crack,while applied electric field retards crack propagation due to the electrostatic tractions.As a direct consequence,the fracture criterion is composed of two parts:the energy release rate must exceed a critical value and the mechanical load must be higher than the critical value for crack opening.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 11072093 and 11121202)
文摘The effect of electric charge on the mechanical properties of graphene under tensile loading is investigated by using molecular dynamics method.A modified atomistic moment method based on the classical electrostatics theory is proposed to obtain the distribution of extra charges induced by an external electric field and net electric charges stored in graphene.The electrostatic interactions between charged atoms are calculated using the coulomb law.The results show that the Young's modulus and the critical fracture stress under uniaxial tension decrease with the increase of electric potential and net charges on graphene.The failure of graphene induced by electric charges is found to be controlled by charge level.The results indicate that the carbon-carbon bonds at the edge of graphene will break first.
基金supported by the Hong Kong Research Grants Council(Grant No. 622610)supported by the Nanotechnology Program at HKUST
文摘The effect of electrostatic tractions on the fracture behavior of a dielectric material under mechanical and/or electric loading is analyzed,by studying a pre-cracked parallel-plate capacitor,and illustrated by plots.The results indicate that electrostatic tractions on the electrodes compress the material in front of the crack tip,while electrostatic tractions on the crack faces have the tendency to close the crack and stretch the material behind the crack tip.Mechanical load is the driving force to propagate the crack,while applied electric field retards crack propagation due to the electrostatic tractions.As a direct consequence,the fracture criterion is composed of two parts:the energy release rate must exceed a critical value and the mechanical load must be higher than the critical value for crack opening.
