Journal ArticleDOI
The correlation of indentation experiments
TLDR
In this article, a simplified theoretical model of this behaviour is obtained by extending R. Hill's theory of expanding a cylindrical or spherical cavity in an elastic-plastic material to ensure compatibility between the volume of material displaced by the indenter and that accommodated by elastic expansion.Abstract:
The theory of rigid perfectly-plastic solids predicts indentation pressures, using wedge-shaped or conical indenters, which depend only on the geometry of the indenter and the yield stress of the material. With blunt wedges or with materials having a low ratio of Young's modulus, E, to yield stress, Y, the material displaced by the indenter is accommodated by an approximately radial expansion of the surrounding material. The indentation pressure then falls below the rigid perfectly-plastic value. In these circumstances, measurements of indentation pressure for a variety of indenter geometries are shown to correlate with the single parameter (E/Y) tan β, where β is the angle of inclination of the indenter to the surface at the edge of the indentation. This parameter may be interpreted as the ratio of the strain imposed by the indenter to the yield strain of the material.
A simplified theoretical model of this behaviour is obtained by extending R. Hill's theory of expanding a cylindrical or spherical cavity in an elastic-plastic material to ensure compatibility between the volume of material displaced by the indenter and that accommodated by elastic expansion.read more
Citations
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Journal ArticleDOI
Plastic strain and strain gradients at very small indentation depths
TL;DR: In this article, the authors compared theoretical results based on geometrically necessary dislocations and semi-empirical experimental continuum calculations are compared for spherical and wedge indenters.
Journal ArticleDOI
Shear deformation under pyramidal indentations in soda-lime glass
TL;DR: In this paper, the nature of the flow lines that occur in the deformed zone in soda-lime glass under pyramidal indentations has been investigated, and it was shown that the spiral flow lines meet at 110°, instead of the 90° required by the ideal rigid-plastic behaviour.
Journal ArticleDOI
Time and temperature dependence of the scratch properties of poly(methylmethacrylate) surfaces
TL;DR: In this article, the geometry of the grooves left on the surface of a viscoelastic viscoplastic body by a moving cone-shaped diamond tip having a radius of about 40 μm was analyzed.
Journal ArticleDOI
An analysis of load–penetration curves from instrumented indentation
Kaiyang Zeng,C.-h Chiu +1 more
TL;DR: In this article, a new empirical method is proposed for analyzing nano-indentation load-displacement curves based on experimental results and finite element (FEM) calculations reported in the literature.
Journal ArticleDOI
An analytical elastic-perfectly plastic contact model
TL;DR: In this paper, a new formulation for elastic-perfectly plastic contact in the normal direction between two round surfaces that is solely based on material properties and contact geometries is developed.
References
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Book
Theory of elasticity
TL;DR: The theory of the slipline field is used in this article to solve the problem of stable and non-stressed problems in plane strains in a plane-strain scenario.
Book
The mathematical theory of plasticity
TL;DR: In this paper, the solution of two-dimensional non-steady motion problems in two dimensions is studied. But the solution is not a solution to the problem in three dimensions.
Journal ArticleDOI
The Elastic Contact of Rough Spheres
J. A. Greenwood,J. H. Tripp +1 more
TL;DR: In this article, the Hertzian theory of elastic contact between spheres is extended by considering one of the spheres to be rough, so that contact occurs, as in practice, at a number of discrete microcontacts.