A Review on Brittle Fracture Nanomechanics by All-Atom Simulations

Abstract

Despite a wide range of current and potential applications, one primary concern of brittle materials is their sudden and swift collapse. This failure phenomenon exhibits an inability of the materials to sustain tension stresses in a predictable and reliable manner. However, advances in the field of fracture mechanics, especially at the nanoscale, have contributed to the understanding of the material response and failure nature to predict most of the potential dangers. In the following contribution, a comprehensive review is carried out on molecular dynamics (MD) simulations of brittle fracture, wherein the method provides new data and exciting insights into fracture mechanism that cannot be obtained easily from theories or experiments on other scales. In the present review, an abstract introduction to MD simulations, advantages, current limitations and their applications to a range of brittle fracture problems are presented. Additionally, a brief discussion highlights the theoretical background of the macroscopic techniques, such as Griffith’s criterion, crack tip opening displacement, J-integral and other criteria that can be linked to the fracture mechanical properties at the nanoscale. The main focus of the review is on the recent advances in fracture analysis of highly brittle materials, such as carbon nanotubes, graphene, silicon carbide, amorphous silica, calcium carbonate and silica aerogel at the nanoscale. These materials are presented here due to their extraordinary mechanical properties and a wide scope of applications. The underlying review grants a more extensive unravelling of the fracture behaviour and mechanical properties at the nanoscale of brittle materials.

Residual stresses in gas tungsten arc welding: a novel phase-field thermo-elastoplasticity modeling and parameter treatment framework

“…To this, references and overview of the origin of this method in the context of continuum mechanics can be found in, e.g., [57] and [102,103]. Apart from PFM of phase-change materials, the PFM has recently been intensively applied within fracture mechanics for solids as well as for porous media as in, e.g., [3,5,[44][45][46]48,82,83], among others. It is also worth mentioning that several research works have recently employed the PFM to study the microstructure evolution, such as the investigation of the growth of the columnar grains accompanied by the solidification process in welding and additive manufacturing process, for example, the works done in [36,63,90,107,108].…”

Advancements in multi‐phase unsaturated porous media fracture

“…In the last few decades, the phase-field method has emerged as a powerful tool that has been applied by the current authors, among other research groups, in fields like fracture mechanics [1][2][3][4] or for modeling of phase-change materials [5,6]. With focus in this contribution on unsaturated porous media fracture, the material under consideration ϕ is composed of immiscible three phases, i.e.…”

Mechanical Properties of Nacre-Like Composites: A Bottom-Up Approach

“…The inorganic layer is made up of calcium carbonate (CaCO 3 ), referred to as aragonite tablets, which are arranged in parallel to each other and in an overlapping pattern, which from the mesoscale appears as a columnar stack [2,6]. The aragonite tablets have high stiffness and low toughness [7][8][9][10]. However, the disadvantage of merely considering aragonite alone or as dry nacre, as it is referred to, is that such material fails in a brittle fashion [2,7,[9][10][11][12].…”

“…The aragonite tablets have high stiffness and low toughness [7][8][9][10]. However, the disadvantage of merely considering aragonite alone or as dry nacre, as it is referred to, is that such material fails in a brittle fashion [2,7,[9][10][11][12]. Interspersed between the organic and inorganic layer is the intra-lamellar protein chitin, which from a nanoscale view, is visibly entwined within and around the aragonite platelets [2,13,14].…”