Size Effects on Mechanical Properties of Micro/Nano Structures

Amir Musa Abazari; Seyed Mohsen Safavi; Ghader Rezazadeh; Luis Guillermo Villanueva

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arXiv · 1508.01322

Size Effects on Mechanical Properties of Micro/Nano Structures

Amir Musa Abazari·Seyed Mohsen Safavi·Ghader Rezazadeh·Luis Guillermo Villanueva

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Abstract

Experiments on Micro- and Nano-mechanical systems (M/NEMS) have shown that their behavior upon bending loads departs in many cases from the classical predictions using Euler-Bernoulli theory and Hooke law. This anomalous response has usually been seen as a dependence of the material properties with the size of the structure, in particular thickness. A theoretical model that allows for quantitative understanding and prediction of this size effect is important for the design of M/NEMS. In this paper, we summarize and analyze the five theories that can be found in the literature: Grain Boundary Theory (GBT), Surface Stress Theory (SST), Residual Stress Theory (RST), Couple Stress Theory (CST) and Surface Elasticity Theory (SET). By comparing these theories with experimental data we propose a simplified model combination of CST and SET that properly fits all considered cases, therefore delivering a simple (two parameters) model that can be used to predict the mechanical properties at the nanoscale.

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Amir Musa Abazari, Seyed Mohsen Safavi, Ghader Rezazadeh, Luis Guillermo Villanueva. 2015-08-06. Size Effects on Mechanical Properties of Micro/Nano Structures. https://arxiv.org/abs/1508.01322

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