Void growth in finite deformation elasto-plasticity due to hydrostatic stress states

Porous bulk metallic glasses (BMGs) exhibit an excellent combination of superior mechanical properties such as high strength, high resilience, large malleability, and energy absorption capacity. However, a mechanistic understanding of their response under diverse states of stress encountered in practical load-bearing applications is lacking in the literature. In this work, this gap is addressed by performing three-dimensional finite element simulations of porous BMGs subjected to a wide range of tensile and compressive states of stress. A unit cell approach is adopted to investigate the mechanical behavior of a porous BMG having 3% porosity. A parametric study of the effect of stress triaxialities T = 0, ±1/3, ±1, ±2, ±3, and ±∞, which correspond to stress states ranging from pure deviatoric stress to pure hydrostatic stress under tension and compression, is conducted. Apart from the influence of T, the effects of friction parameter, strain-softening parameter and Poisson’s ratio on the mechanics of deformation of porous BMGs are also elucidated. The results are discussed in terms of the simulated stress-strain curves, pore volume fraction evolution, strain to failure, and development of plastic deformation near the pore. The present results have important implications for the design of porous BMG structures.

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Inverse asymptotic solution method for finite deformation elasto-plasticity

Applied Mathematics and Mechanics ◽

10.1007/bf00132796 ◽

1997 ◽

Vol 18 (11) ◽

pp. 1029-1036 ◽

Cited By ~ 1

Author(s):

Chen Zhida

Keyword(s):

Asymptotic Solution ◽

Finite Deformation ◽

Solution Method ◽

Asymptotic Solution Method ◽

Elasto Plasticity

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A Presentation and Comparison of Two Large Deformation Viscoelasticity Models

Journal of Engineering Materials and Technology ◽

10.1115/1.2812252 ◽

1997 ◽

Vol 119 (3) ◽

pp. 251-255 ◽

Cited By ~ 69

Author(s):

Sanjay Govindjee ◽

Stefanie Reese

Keyword(s):

Large Deformation ◽

Plane Strain ◽

Finite Deformation ◽

Strain Relaxation ◽

Elastic Equilibrium ◽

Alternative Formulation ◽

Small Perturbations ◽

Elasto Plasticity

In this paper we present a theory of finite deformation viscoelasticity. The presentation is not restricted to small perturbations from the elastic equilibrium in contrast to many viscoelasticity theories. The fundamental hypothesis of our model is the multiplicative viscoelastic decomposition of Sidoroff (1974). This hypothesis is combined with the assumption of a viscoelastic potential to give a model that is formally similar to finite associative elasto-plasticity. Examples are given to compare the present proposal to an alternative formulation in the literature for the cases of uniaxial plane strain relaxation and creep.

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The influence of hydrostatic stress states on the hydrogen solubility in martensitic steels

Scripta Materialia ◽

10.1016/j.scriptamat.2014.04.006 ◽

2014 ◽

Vol 84-85 ◽

pp. 23-26 ◽

Cited By ~ 17

Author(s):

D. Guedes ◽

A. Oudriss ◽

S. Frappart ◽

G. Courlit ◽

S. Cohendoz ◽

...

Keyword(s):

Hydrostatic Stress ◽

Hydrogen Solubility ◽

Martensitic Steels ◽

Stress States

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The Effects of Passivation Thickness and Initial Aluminum Line Stress on Electromigration Behavior

MRS Proceedings ◽

10.1557/proc-516-249 ◽

1998 ◽

Vol 516 ◽

Cited By ~ 2

Author(s):

Samantha Lee ◽

John C. Bravman ◽

Paul A. Flinn ◽

Tom N. Marieb

Keyword(s):

Finite Element ◽

Hydrostatic Stress ◽

Thickness Effect ◽

Detectable Effect ◽

Unexpected Result ◽

Wafer Level ◽

X Ray Diffraction ◽

X Ray ◽

Stress States ◽

Sample Set

AbstractThe electromigration behavior of pure Al lines passivated with oxides of different thicknesses and passivation deposition temperatures was studied. The initial hydrostatic stress states of the passivated Al lines were modeled with finite element modeling (FEM), and, when possible, measured with X-ray diffraction. Conventional wafer-level electromigration tests showed a clear passivation thickness effect, but no detectable effect of initial stress on electromigration lifetimes. Increasing the passivation thickness increased the electromigration lifetimes, which has been observed by other researchers. However, in a sample set where the Al lines were covered with a thin (0. 1µm) oxide layer, the lifetimes were much longer than expected. Differences in the damage morphology and the failure mechanism between the thin and thicker oxides accounted for this unexpected result.

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