The self-rehabilitation properties of intelligent concrete structures reinforced with superelastic SMA strands are experimentally investigated. The influence of superelastic SMAs on the damping ratio of concrete colum...
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Reservoir revetment on cold regions are often frost damaged resulting from the joint action of low-temperature and cryogenic environment in winter, and then reservoir revetments are often broken to decline the usage f...
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To obtain the damage effect in the process of elasto-plasticity deformation of quasi-brittle materials, the isotropic damage loading-unloading function and damage variable were introduced to non-continuous bifurcation...
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To obtain the damage effect in the process of elasto-plasticity deformation of quasi-brittle materials, the isotropic damage loading-unloading function and damage variable were introduced to non-continuous bifurcation. The critical bifurcation orientation and its corresponding hardening modulus for quasi-brittle materials were derived considering the effect of stiffness degradation and volumetric dilatancy under the assumption of isotropic damage. The relationships of localized orientation angle and maximal hardening modulus dependent on degree of damage and initial Poisson's ratio of rock were explored. Comparative analyses were conducted to study the bifurcation of uniaxial tension-compression samples under the conditions of plane stress and plane strain. It is shown that as the initial Poisson's ratio or degree of damage increases, the localization orientation angle of the plane uniaxial compression sample tends to be initiated to decrease. However, the localization orientation angle of the plane uniaxial tension sample tends to be initiated to increase. The sum of orientation angle under tension and compression conditions is 90°. There are plane stress and plane strain cases of the maximum hardening modulus that is independent of the uniaxial compression and tension.
To investigate the influence of shape memory alloys (SMAs) on the dynamic properties (mainly refers to the frequency and the damping ratio) of concrete columns, the vibration curves of the concrete column reinforced w...
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A unified viscoplasticity constitutive model for metal materials is developed within the framework of irreversible thermodynamics, and an expression for the Helmholtz free energy function involving the parameters refl...
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A unified viscoplasticity constitutive model for metal materials is developed within the framework of irreversible thermodynamics, and an expression for the Helmholtz free energy function involving the parameters reflecting kinematic hardening and isotropic hardening is given. At the same time a non-associated flow potential function including the corresponding state variables is also given, from which the flow equation and the evolution equations of the internal state variables are derived. Thus, a general theoretical framework constructing a unified viscoplasticity constitutive model is given. Compared with the typical unified viscoplasticity constitutive models, the presented model evidently satisfies the irreversible thermodynamics laws. Moreover, this method not only provides a new theoretical foundation for further development of the unified viscoplasticity constitutive model, but also gives a new theoretical framework for the stress-strain analysis of more materials.
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