I/II Mixed Mode Fracture in Graphene
Nanoscale fracture of pre-cracked graphene under coupled in-plane opening and shear mechanical loading in far-field is investigated by extensive molecular dynamics simulations.Under opening-dominant loading,zigzag edge cracks grow self-similarly.Otherwise,complex mechanical stresses concentrated in the vicinity of crack tip can manipulate the direction of crack initiation changing by 30° (or multiples of 30°) to the original crack line.Toughness determined from obtained critical stress intensity factors 2.63 ~ 3.38 nN ?-3/2 is relatively low,which demonstrates graphene is intrinsically brittle opposite to its exceptional high strength at room temperature.Graphene is easier to break along zigzag direction.Torn edges are in either zigzag or armchair manner,while zigzag edges are observed prevalently,and armchair edges are formed occasionally under particular loading conditions.Crack kinking is related to the proportion of opening and shear components of loading,and topological defects frequently appear at turning points.Our theoretical results indicate that cracking of graphene has a dependence on local mechanical stresses,edge energy and dynamic effects,which provide a possible way to regulate the edge structure of graphene
Graphene Crack kinking Stress intensity factor Molecular dynamics
Bin Zhang Lanjv Mei
State Key Laboratory of Mechanics and Control of Mechanical Structures,and College of Aerospace Engineering,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China
国际会议
北京
英文
1-9
2013-06-16（万方平台首次上网日期，不代表论文的发表时间）