Atomistic basis for the plastic yield criterion of metallic glass

2003 ◽  
Vol 2 (7) ◽  
pp. 449-452 ◽  
Author(s):  
Christopher A. Schuh ◽  
Alan C. Lund
Keyword(s):  
Metallic Glass ◽  
Yield Criterion ◽  
Plastic Yield

A yield criterion for Pd40Ni40P20 metallic glass

1989 ◽  
Vol 37 (2) ◽  
pp. 445-456 ◽  
Author(s):  
P.E. Donovan
Keyword(s):  
Metallic Glass ◽  
Yield Criterion

Influence of the loading rate on the indentation response of Ti-based metallic glass

2009 ◽  
Vol 24 (3) ◽  
pp. 918-925 ◽  
Author(s):  
J. Sort ◽  
J. Fornell ◽  
W. Li ◽  
S. Suriñach ◽  
M.D. Baró
Keyword(s):  
Metallic Glass ◽  
Free Volume ◽  
Mechanical Response ◽  
Loading Rate ◽  
Yield Criterion ◽  
Contact Stiffness ◽  
Strain Rates ◽  
Cohesive Stress ◽  
Crystalline Materials ◽  
Loading Rates

The mechanical behavior of Ti-based metallic glass has been investigated by means of indentation experiments at different loading rates. Contrary to many crystalline materials, an increase of the loading rate causes a reduction of hardness, i.e., a mechanical softening. This effect is ascribed to deformation-induced creation of excess free volume, which is more pronounced for higher strain rates. The decrease of hardness is accompanied with an increase of the contact stiffness and a reduction of the reduced elastic modulus. Finite element simulations reveal that the mechanical response of this material can be described using the Mohr-Coulomb yield criterion. The changes in the nanoindentation curves with the increase of loading rate are well reproduced by decreasing the value of the Mohr-Coulomb cohesive stress. This result is consistent with the presumed enhancement of free volume.

scholarly journals MAPPROXIMATING STRESSES IN THE VICINITY OF A CAVITY EXPANDING AT A CONSTANT VELOCITY IN A MEDIUM WITH THE MOHR - COULOMB PLASTICITY CONDITION

2019 ◽  
Vol 81 (2) ◽  
pp. 177-190 ◽  
Author(s):  
V. L. Kotov
Keyword(s):  
Constant Velocity ◽  
Yield Criterion ◽  
Plastic Region ◽  
Plasticity Condition ◽  
Practical Applications ◽  
Plastic Yield ◽  
Runge Kutta Method ◽  
Wide Range ◽  
Self Similar Solution ◽  
Internal Friction Coefficient

A one-dimensional problem of a spherical cavity expanding at a constant velocity from a point in an infinite elastoplastic medium is considered. The problem has a first-kind self-similar solution. Elastoplastic deformation of the soil is described based on Hooke's law and the Mohr-Coulomb yield criterion. An analytical solution of the problem in the elastic region contacting with the plastic yield region has been obtained. To determine stress and velocity fields in the plastic region, a known algorithm, based on the shooting method, of analyzing a boundary-value problem for a system of two first-order ordinary differential equations, including the fourth-order Runge - Kutta method, has been realized. An effective algorithm of numerically analyzing an expanding cavity problem, earlier proposed in the works by М. Forrestal et al., makes it possible to solve the problem accurately enough for practical applications. A formula for determining the critical pressure - the minimal pressure required for the nucleation, accounting for internal pressure of a cavity in the framework of the Mohr - Coulomb yield criterion, has been derived, which is a generalization of the earlier published solution for an elastic ideally plastic medium with Tresca's criterion. The obtained critical value was compared with a numerical solution in a full formulation at the cavity expansion velocities close to zero in a wide range of variation of the parameters of the Mohr - Coulomb yield criterion. It is shown that the inaccuracy of the approximation of the proposed formula does not exceed 6% for the variation of the internal friction coefficient all over the admissible range, and for the initial value of the yield strength increasing by three orders of magnitude.

Unified plastic yield criterion for ductile solids.

AIAA Journal ◽  
1973 ◽  
Vol 11 (10) ◽  
pp. 1428-1429 ◽  
Author(s):  
MANOJ MAITRA ◽  
KAMALESH MAJUMDAR ◽  
ANIRUDDHA DAS
Keyword(s):  
Yield Criterion ◽  
Plastic Yield

Large-Deflection Bending of Clamped Metal Foam-Filled Rectangular Tubes

2017 ◽  
Vol 09 (03) ◽  
pp. 1750043 ◽  
Author(s):  
Jianxun Zhang ◽  
Qinghua Qin ◽  
Yan Yang ◽  
Xuehui Yu ◽  
Shangjun Chen ◽  
...  
Keyword(s):  
Analytical Model ◽  
Large Deflection ◽  
Metal Foam ◽  
Yield Criterion ◽  
Structural Response ◽  
Flat Punch ◽  
Plastic Yield ◽  
Rectangular Tube ◽  
Foam Filled ◽  
Rectangular Tubes

Large-deflection bending of fully clamped slender metal foam-filled rectangular tubes is investigated theoretically, experimentally and numerically. A plastic yield criterion for the foam-filled rectangular tube is proposed. Considering the filled foam strength effect and the interaction of bending and stretching, an analytical solution is proposed to predict the structural response of the foam-filled rectangular tubes transversely loaded by a flat punch. Clamped bending tests of aluminium alloy foam-filled rectangular tubes are conducted. The analytical model captures experimental results reasonably. Numerical calculations are carried out to predict the large-deflection behavior of the foam-filled tubes, and good agreement is achieved between the analytical solutions and numerical results. The effects of wall thickness of tube, punch size and filled foam strength are discussed in detail. It is demonstrated that the present analytical model can reasonably predict the post-yield behavior of the foam-filled rectangular tube.

Atomic-Scale Study of Plastic-Yield Criterion in Nanocrystalline Cu at High Strain Rates

2009 ◽  
Vol 41 (2) ◽  
pp. 523-531 ◽  
Author(s):  
A.M. Dongare ◽  
A.M. Rajendran ◽  
B. Lamattina ◽  
D.W. Brenner ◽  
M.A. Zikry
Keyword(s):  
High Strain ◽  
Yield Criterion ◽  
Atomic Scale ◽  
Strain Rates ◽  
High Strain Rates ◽  
Plastic Yield

A Yield Criterion Based on Mean Shear Stress

2014 ◽  
Vol 611-612 ◽  
pp. 3-10
Author(s):  
Wilko C. Emmens ◽  
A.H. van den Boogaard
Keyword(s):  
Shear Stress ◽  
Plane Strain ◽  
Yield Criterion ◽  
Maximum Shear Stress ◽  
Crystallographic Direction ◽  
Yield Criteria ◽  
General Finding ◽  
Plastic Yield ◽  
Yield Loci ◽  
Actual Orientation

This work investigates the relation between shear stress and plastic yield considering that a crystal can only deform in a limited set of directions. The shear stress in arbitrary directions is mapped for some cases showing relevant differences. Yield loci based on mean shear stress are constructed. The Tresca yield criterion can be improved by averaging the shear stress over directions near the direction of maximum shear stress. Yield criteria based on averaging over crystallographic direction show a clear influence of the actual orientation of these direction, notably in case of few crystallographic directions. The general finding is that the higher the isotropy of a material, the lower the plane strain factor. The shape of the yield loci is comparable to those derived by the Hershey criterion with exponents lower than 3.

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