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
Indentation of pressurized viscoplastic polymer spherical shells
Viggo Tvergaard,Alan Needleman +1 more
TL;DR: In this paper, the indentation response of polymer spherical shells is investigated for axisymmetric deformations with a conical indenter, and the results show the effects of shell thickness, internal pressure and polymer constitutive characterization on this transition and on the deformation modes in each of these regimes.
Journal ArticleDOI
Flexible manufacturing systems evaluation: An alternative approach
TL;DR: In this paper, a stochastic, static one-period problem is formulated, and a measure that takes into account both the capital costs of implementing the new technology and the random monetary value of its output is identified to solve the problem.
Journal ArticleDOI
Determination of elastoplastic properties of TiO2 thin films deposited on dual phase stainless steel using nanoindentation tests
TL;DR: In this article, the mechanical properties of a 1 µm thin film (1 µm thickness) deposited by spin coating on dual phase Duplex stainless steel and glass substrates were investigated.
Journal ArticleDOI
Second-order effects at microindentation of elastic polymers using sharp indenters
Yasir Kamran,Per-Lennart Larsson +1 more
TL;DR: In this article, the sharp indentation of elastic polymers is investigated numerically using the finite element method, and large deformation theory is relied upon for accuracy, both cone and Vickers indentation is considered.
Journal ArticleDOI
Tribological and mechanical characterization of epoxy/graphite composite coatings: Effects of particles’ size and oxidation:
Nedia Gafsi,Imen Smaoui,Raquel Verdejo,Mohamed Kharrat,Miguel A. López Manchado,Maher Dammak +5 more
TL;DR: In this paper, the mechanical and tribological properties of an epoxy matrix filled with different graphitic particles deposited on an aluminum substrate by the electrostatic spray were investigated, and the results showed that the polygonal properties of the polymeric matrix were similar to those of the graphitic matrix.
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.