▎ 摘　　要

The uniaxial tensile strength of graphene nanosheets at 77 K was determined by the method of loading two-dimensional nano-objects with strong electric fields. It was shown that, for graphene sheets 0.5 to 2.8 nm thick, the maximum strength within the measurement error does not depend on the thickness of the sheets. The average strength, due to significant statistical dispersion, was 43% lower than its maximum value (92 GPa). The strength of graphene nanosheets is almost an order of magnitude greater than the strength of nanoneedle samples made from original carbon fibres. Evidence that graphene nanosheet strength does not depend upon sheet depth indicates the achievement of the ideal strength of these objects. Published by AIP Publishing.