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Full-Text Articles in Engineering
The Effect Of Cryogenic Thermal Cycling On Aging, Rejuvenation, And Mechanical Properties Of Metallic Glasses, Nikolai V. Priezjev
The Effect Of Cryogenic Thermal Cycling On Aging, Rejuvenation, And Mechanical Properties Of Metallic Glasses, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
The structural relaxation, potential energy states, and mechanical properties of a model glass subjected to thermal cycling are investigated using molecular dynamics simulations. We study a non-additive binary mixture which is annealed with different cooling rates from the liquid phase to a low temperature well below the glass transition. The thermal treatment is applied by repeatedly heating and cooling the system at constant pressure, thus temporarily inducing internal stresses upon thermal expansion. We find that poorly annealed glasses are relocated to progressively lower levels of potential energy over consecutive cycles, whereas well annealed glasses can be rejuvenated at sufficiently large …
Slow Relaxation Dynamics In Binary Glasses During Stress-Controlled, Tension-Compression Cyclic Loading, Nikolai V. Priezjev
Slow Relaxation Dynamics In Binary Glasses During Stress-Controlled, Tension-Compression Cyclic Loading, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
The effect of cyclic loading on relaxation dynamics and mechanical properties of metallic glasses is studied using molecular dynamics simulations. We consider the Kob-Andersen three-dimensional binary mixture rapidly cooled across the glass transition and subjected to thousands of tension-compression cycles in the elastic range. It was found that during cyclic loading at constant pressure, the system is relocated to progressively lower levels of the potential energy, thus promoting greater densification and higher strength. Furthermore, with increasing stress amplitude, the average glass density increases and the minimum of the potential energy becomes deeper, while the elastic modulus is reduced. The typical …
The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev
The Yielding Transition In Periodically Sheared Binary Glasses At Finite Temperature, Nikolai V. Priezjev
Mechanical and Materials Engineering Faculty Publications
Non-equilibrium molecular dynamics simulations are performed to investigate the dynamic behavior of three-dimensional binary glasses prepared via an instantaneous quench across the glass transition. We found that with increasing strain amplitude up to a critical value, the potential energy approaches lower minima in steady state, whereas the amplitude of shear stress oscillations becomes larger. Below the yielding transition, the storage modulus dominates the mechanical response, and the gradual decay of the potential energy over consecutive cycles is accompanied by reduction in size of transient clusters of atoms with large nonaffine displacements. In contrast, above the yield strain, the loss modulus …