Experimental determination of the effective surface energy density in dynamic problems of fracture mechanics

The finite plane deformation of nanomaterial surrounding an elliptical hole subjected to remote loading is systematically investigated using a recently developed continuum theory. A complex variable formulation is utilized to obtain a closed-form solution for the hoop stress along the edge of the hole. The results show that when the size of the hole reduces to the same order as the ratio of the surface energy density to the applied remote stress, the influence of the surface energy density plays an even more significant role, and the shape of the hole coupled with surface energy density has a significant effect on the elastic state around the hole. Surprisingly, in the absence of any external loading, the hoop stress induced solely by surface effects is identical to that for a hole with surface energy in a linearly elastic solid derived by the Gurtin–Murdoch surface elasticity model. The results in this paper should be useful for the precise design of nanodevices and helpful for the reasonable assessment of test results of nano-instruments.

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Size-Dependent Elasticity of Nanoporous Materials Predicted by Surface Energy Density-Based Theory

Journal of Applied Mechanics ◽

10.1115/1.4036345 ◽

2017 ◽

Vol 84 (6) ◽

Cited By ~ 1

Author(s):

Yin Yao ◽

Yazheng Yang ◽

Shaohua Chen

Keyword(s):

Energy Density ◽

Surface Energy ◽

Volume Fraction ◽

Surface Effect ◽

Compressive Strain ◽

Nanoporous Materials ◽

Surface Relaxation ◽

Surface Energy Density ◽

Closed Form Solutions ◽

Size Dependent

The size effect of nanoporous materials is generally believed to be caused by the large ratio of surface area to volume, so that it is also called surface effect. Based on a recently developed elastic theory, in which the surface effect of nanomaterials is characterized by the surface energy density, combined with two micromechanical models of composite materials, the surface effect of nanoporous materials is investigated. Closed-form solutions of both the effective bulk modulus and the effective shear one of nanoporous materials are achieved, which are related to the surface energy density of corresponding bulk materials and the surface relaxation parameter of nanomaterials, rather than the surface elastic constants in previous theories. An important finding is that the enhancement of mechanical properties of nanoporous materials mainly results from the compressive strain induced by nanovoid's surface relaxation. With a fixed volume fraction of nanovoids, the smaller the void size, the harder the nanoporous material will be. The results in this paper should give some insights for the design of nanodevices with advanced porous materials or structures.

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Experimental determination of the {111}/{001} surface energy ratio for Pd crystals

Applied Physics Letters ◽

10.1063/5.0022879 ◽

2020 ◽

Vol 117 (10) ◽

pp. 101601

Author(s):

Peiyu Chen ◽

Yakun Gao ◽

Martin R. Castell

Keyword(s):

Surface Energy ◽

Experimental Determination ◽

Energy Ratio

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The effective surface energy of heterogeneous solids measured by inverse gas chromatography at infinite dilution

Journal of Colloid and Interface Science ◽

10.1016/s0021-9797(02)00238-2 ◽

2003 ◽

Vol 260 (2) ◽

pp. 443-448 ◽

Cited By ~ 17

Author(s):

Chenhang Sun ◽

John C. Berg

Keyword(s):

Gas Chromatography ◽

Surface Energy ◽

Infinite Dilution ◽

Inverse Gas Chromatography ◽

Effective Surface ◽

Heterogeneous Solids ◽

Effective Surface Energy

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Mechanism of preferential nucleation of [\bf 1{\overline 1}0{\overline 3}]-oriented GaN twins on an SiO2-patternedm-plane sapphire substrate

Journal of Applied Crystallography ◽

10.1107/s1600576714027873 ◽

2015 ◽

Vol 48 (1) ◽

pp. 195-199 ◽

Cited By ~ 2

Author(s):

Hansub Yoon ◽

Miyeon Jue ◽

Hyemi Lee ◽

Sanghwa Lee ◽

Chinkyo Kim

Keyword(s):

Growth Rate ◽

Surface Energy ◽

Sapphire Substrate ◽

Legendre Transformation ◽

Growth Morphology ◽

Effective Surface ◽

Crystalline Domain ◽

Preferential Nucleation ◽

Effective Surface Energy

The mechanism of preferential nucleation of [1{\overline 1}0{\overline 3}]-oriented GaN faceted twins on an SiO2-patternedm-plane sapphire substrate was investigated. Each variant of twins, which were enclosed byc- andm-facets, was observed to be preferentially nucleated over the opposite sides of an SiO2pattern. It was hypothesized, from the fact that the same method of Legendre transformation is applied to a Wulff plot and a kinetic Wulff plot to determine the growth morphology of a crystalline domain, that theeffectivesurface energy ofc- andm-facets would be proportional to the growth rate of the respective facet. On the basis of this hypothesis, minimization of the effective surface energy of a nucleated domain was proposed as a mechanism of preferential nucleation. This proposed mechanism successfully explained the preferential nucleation behaviour.

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