TY - JOUR
T1 - Effect of crack length and orientation on the mixed-mode fracture behavior of graphene
AU - Datta, Dibakar
AU - Nadimpalli, Siva P.V.
AU - Li, Yinfeng
AU - Shenoy, Vivek B.
N1 - Funding Information:
DD and VBS gratefully acknowledge the support of the Army Research Office through contract W911NF-11-1-0171 and National Science Foundation . SPVN would like to acknowledge the support of New Jersey Institute of Technology through faculty startup research grant. Y.L gratefully acknowledge the support of the National Basic Research Program of China (No. 11402145 ), State Key Laboratory of Ocean Engineering (No. GKZD010065 ). The computational support for this work was provided by the Center for Computation and Visualization of Brown University and the Penn Institute of Computational Science at the University of Pennsylvania.
Publisher Copyright:
© 2015 Elsevier Ltd.
PY - 2015
Y1 - 2015
N2 - In almost all practical situations, graphene based nanodevices are subjected to complex loading i.e., combination of shear and tensile stress. Given this situation, mixed-mode fracture is inevitable during tearing of graphene. However, most of the studies on graphene fracture are based on mode-I fracture which is an idealistic situation and rarely occurs in the service conditions. We, therefore, performed classical molecular dynamics (MD) simulations on a graphene sheet with crack like flaw and investigated the complex mixed-mode fracture behavior. Mode-I, mode-II, and mixed-mode stress intensity factors (KI, KII, and Keff respectively) as a function of Φ and crack length in armchair and zigzag edges were calculated. In addition, we investigated the effect of slit length and angle on the strength of graphene sheet. Effective stress intensity factor increases with flaw size and reaches a plateau (between 3.10 and 3.80MPa√m for armchair, between 2.60 and 3.10MPa√m for zigzag) approximately at a crack length of a/b≈0.11 (2a and 2b are crack and model size respectively). For crack with zigzag edge surface, existence of a single bond perpendicular to crack direction facilitates bond-breaking process. While for armchair surface case, two inclined bonds at crack tip offer relatively more resistance. Finally, the effect of mixed-mode loading on the crack propagation path was investigated. All the systems considered in this study mimic real service conditions. Hence, our findings will provide useful guidelines for the design of graphene-based nanodevices.
AB - In almost all practical situations, graphene based nanodevices are subjected to complex loading i.e., combination of shear and tensile stress. Given this situation, mixed-mode fracture is inevitable during tearing of graphene. However, most of the studies on graphene fracture are based on mode-I fracture which is an idealistic situation and rarely occurs in the service conditions. We, therefore, performed classical molecular dynamics (MD) simulations on a graphene sheet with crack like flaw and investigated the complex mixed-mode fracture behavior. Mode-I, mode-II, and mixed-mode stress intensity factors (KI, KII, and Keff respectively) as a function of Φ and crack length in armchair and zigzag edges were calculated. In addition, we investigated the effect of slit length and angle on the strength of graphene sheet. Effective stress intensity factor increases with flaw size and reaches a plateau (between 3.10 and 3.80MPa√m for armchair, between 2.60 and 3.10MPa√m for zigzag) approximately at a crack length of a/b≈0.11 (2a and 2b are crack and model size respectively). For crack with zigzag edge surface, existence of a single bond perpendicular to crack direction facilitates bond-breaking process. While for armchair surface case, two inclined bonds at crack tip offer relatively more resistance. Finally, the effect of mixed-mode loading on the crack propagation path was investigated. All the systems considered in this study mimic real service conditions. Hence, our findings will provide useful guidelines for the design of graphene-based nanodevices.
KW - Crack propagation
KW - Graphene
KW - Mixed-mode fracture
KW - Molecular dynamics
KW - Stress intensity factors
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U2 - 10.1016/j.eml.2015.08.005
DO - 10.1016/j.eml.2015.08.005
M3 - Article
AN - SCOPUS:84942045209
SN - 2352-4316
VL - 5
SP - 10
EP - 17
JO - Extreme Mechanics Letters
JF - Extreme Mechanics Letters
ER -