Prvoprincipiální studie vanadiových kompozitů vyztužených wolframovými nano-vlákny

First Principles Study of Vanadium Based Composites Reinforced by Tungsten Nano-fibres

abstrakt

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Calculations of elastic moduli and theoretical uniaxial strength of unidirectional composite having continuous nano-fibre reinforcements are performed using ab initio method. All quantities are computed from the dependence of crystal energy on a suitable deformation parameter. Results for tungsten nano-fibres in vanadium matrix are presented as a particular example of the analysis. Obtained results are used to verify validity of macro-scale empirical relations for composites (rules of mixtures) on the nano-scale. The dependence of the computed composite elastic moduli on the atomic concentration of W (nearly corresponding to the volume fraction of fibres) is compared with a simple rule of mixture for an ideal composite (with the fibre effectivity of 1). Results show that validity of the linear mixture rule is theoretically justified for most of them. On the other hand, computed values of theoretical strength and Young modulus exhibit a simple increasing dependence on atomic concentration of W only up to about 70% concentration. Then the values become saturated or even slightly decrease.

Calculations of elastic moduli and theoretical uniaxial strength of unidirectional composite having continuous nano-fibre reinforcements are performed using ab initio method. All quantities are computed from the dependence of crystal energy on a suitable deformation parameter. Results for tungsten nano-fibres in vanadium matrix are presented as a particular example of the analysis. Obtained results are used to verify validity of macro-scale empirical relations for composites (rules of mixtures) on the nano-scale. The dependence of the computed composite elastic moduli on the atomic concentration of W (nearly corresponding to the volume fraction of fibres) is compared with a simple rule of mixture for an ideal composite (with the fibre effectivity of 1). Results show that validity of the linear mixture rule is theoretically justified for most of them. On the other hand, computed values of theoretical strength and Young modulus exhibit a simple increasing dependence on atomic concentration of W only up to about 70% concentration. Then the values become saturated or even slightly decrease.

Calculations of elastic moduli and theoretical uniaxial strength of unidirectional composite having continuous nano-fibre reinforcements are performed using ab initio method. All quantities are computed from the dependence of crystal energy on a suitable deformation parameter. Results for tungsten nano-fibres in vanadium matrix are presented as a particular example of the analysis. Obtained results are used to verify validity of macro-scale empirical relations for composites (rules of mixtures) on the nano-scale. The dependence of the computed composite elastic moduli on the atomic concentration of W (nearly corresponding to the volume fraction of fibres) is compared with a simple rule of mixture for an ideal composite (with the fibre effectivity of 1). Results show that validity of the linear mixture rule is theoretically justified for most of them. On the other hand, computed values of theoretical strength and Young modulus exhibit a simple increasing dependence on atomic concentration of W only up to about 70% concentration. Then the values become saturated or even slightly decrease.

24.09.2006

Wroclaw

PSIK/COST workshop booklet

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