Predicting the lifetime of nanoelements: a new trend in micromechanics

K Sergiy and T Andrei and K Eugene and M Yuriy and S Nataliya, 1ST VIRTUAL EUROPEAN CONFERENCE ON FRACTURE - VECF1, 28, 116-123 (2020).

DOI: 10.1016/j.prostr.2020.10.015

The beginning of practical use nanoelements and nanodevices necessitates both the assessment of structural integrity and the lifetime prediction of nanodevices. Solving this problem requires fundamentally new approaches, which should take into account the specific features of atomic structure and mechanisms of instability and failure of nanoelements. This paper discusses the main effects that govern the lifetime of nanoelements, and an approach is formulated to predict their lifetime on this basis. It is shown that the fluctuation-induced breaking of the atomic bond under the action of a force field is the key factor governing the lifetime of nanoelements. Under certain conditions, synergistic effects of temperature and mechanical loading on the lifetime are possible. This yields a catastrophic fall in the lifetime of nanoelements. It is found that the existence of an instability region in tension of nanoelements containing contact bonds is the reason for synergism. A fluctuation model of the lifetime of nanoelements is suggested that is focused on taking into account the combined effect of temperature and mechanical load. Within the framework of this model, a statistical law is obtained for the probability of failure of nanoelements. This, in particular, made it possible to derive not only the dependence for the average time to fracture on the magnitude of load and temperature, but also to predict the scatter of lifetime values with a given probability. The features of quantum-mechanical effects in nanoelements are analyzed using CGN with different lengths of a carbyne chain connecting graphene sheets, as an example. The essence of this effect is that the lifetime depends on whether the number of atoms in the carbyne chain is even or odd ("even odd" effect). Inversion of this effect under mechanical load is a key factor for CGNs use in straintronics devices. On the whole, the temperature range is ascertained, where practical use of CGNs is possible. (C) 2020 The Authors. Published by Elsevier B.V.

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