The Experts below are selected from a list of 171855 Experts worldwide ranked by ideXlab platform
A.r.s. Ponter - One of the best experts on this subject based on the ideXlab platform.
-
Extremal properties of endochronic plasticity, part II: Extremal path of the constitutive equation with a yield surface and application
International Journal of Plasticity, 1993Co-Authors: Xianghe Peng, A.r.s. PonterAbstract:Abstract Extremal paths for endochronic constitutive equations without using a yield surface and the corresponding principle of minimum potential work were obtained in Part I of this article. In this paper, the extremal properties of endochronic constitutive equation with a yield surface and the corresponding method for deformation bound Analysis are proposed. An example is presented that demonstrates that the application of endochronic constitutive models to Simplified Analysis is not significantly different from classical models due to the derived extremal properties. The adopted constitutive model involves both nonlinear isotropic and kinematic hardening, which may provide more accurate results in Simplified and bounding Analysis.
-
Extremal properties of endochronic plasticity, part I: Extremal path of the constitutive equation without a yield surface
International Journal of Plasticity, 1993Co-Authors: Xianghe Peng, A.r.s. PonterAbstract:Abstract Based on the general extremal properties of time-independent inelastic materials proposed by Ponter and Martin, some extremal properties of endochronic theory of plasticity are investigated. The extremal path of an endochronic constitutive equation without using a yield surface is found, which makes plastic work act as a potential such that the deviatoric stress can be derived from its derivative with respect to plastic strain. These properties are important because they provide the possibility for the irreversible thermodynamically based constitutive equation, which is strongly history-dependent, to be applied to Simplified Analysis in engineering problems. Using the derived extremal properties, the principle of minimum potential energy is extended to endochronic theory of plasticity. As an example, the stress and strain field of a hinge-joint three-bar truss are analyzed.
Xianghe Peng - One of the best experts on this subject based on the ideXlab platform.
-
Extremal properties of endochronic plasticity, part II: Extremal path of the constitutive equation with a yield surface and application
International Journal of Plasticity, 1993Co-Authors: Xianghe Peng, A.r.s. PonterAbstract:Abstract Extremal paths for endochronic constitutive equations without using a yield surface and the corresponding principle of minimum potential work were obtained in Part I of this article. In this paper, the extremal properties of endochronic constitutive equation with a yield surface and the corresponding method for deformation bound Analysis are proposed. An example is presented that demonstrates that the application of endochronic constitutive models to Simplified Analysis is not significantly different from classical models due to the derived extremal properties. The adopted constitutive model involves both nonlinear isotropic and kinematic hardening, which may provide more accurate results in Simplified and bounding Analysis.
-
Extremal properties of endochronic plasticity, part I: Extremal path of the constitutive equation without a yield surface
International Journal of Plasticity, 1993Co-Authors: Xianghe Peng, A.r.s. PonterAbstract:Abstract Based on the general extremal properties of time-independent inelastic materials proposed by Ponter and Martin, some extremal properties of endochronic theory of plasticity are investigated. The extremal path of an endochronic constitutive equation without using a yield surface is found, which makes plastic work act as a potential such that the deviatoric stress can be derived from its derivative with respect to plastic strain. These properties are important because they provide the possibility for the irreversible thermodynamically based constitutive equation, which is strongly history-dependent, to be applied to Simplified Analysis in engineering problems. Using the derived extremal properties, the principle of minimum potential energy is extended to endochronic theory of plasticity. As an example, the stress and strain field of a hinge-joint three-bar truss are analyzed.
Xuelai Zhang - One of the best experts on this subject based on the ideXlab platform.
-
Simplified Analysis of heat and mass transfer model in droplet evaporation process
Applied Thermal Engineering, 2016Co-Authors: Yunyun Wu, Xiaosong Zhang, Xuelai ZhangAbstract:Abstract A Simplified model on single droplet evaporation into a stagnant gas space is established. The mathematical model is based on molecule diffusion on the droplet surface subjected to boundary conditions of constant temperature and conduction heat transferring on the external surface of the spherical droplet. Constant thermal properties are assumed throughout the Analysis for the droplet. Non-linear empirical equations are applied to the ODEs in the numerical solution to expand its range of applicability. The effects of variables, such as surrounding temperature and humidity, and droplet initial radius were investigated. Furthermore, a comparison is made between the present study and the numerical or analytical solution given in the literature. The results show that the present model can give better results than other numerical or analytical solutions presented in the literature.
-
Simplified Analysis of heat and mass transfer model in droplet evaporation process
Applied Thermal Engineering, 2016Co-Authors: Yunyun Wu, Xiaosong Zhang, Xuelai ZhangAbstract:Abstract A Simplified model on single droplet evaporation into a stagnant gas space is established. The mathematical model is based on molecule diffusion on the droplet surface subjected to boundary conditions of constant temperature and conduction heat transferring on the external surface of the spherical droplet. Constant thermal properties are assumed throughout the Analysis for the droplet. Non-linear empirical equations are applied to the ODEs in the numerical solution to expand its range of applicability. The effects of variables, such as surrounding temperature and humidity, and droplet initial radius were investigated. Furthermore, a comparison is made between the present study and the numerical or analytical solution given in the literature. The results show that the present model can give better results than other numerical or analytical solutions presented in the literature.
Sheel Aditya - One of the best experts on this subject based on the ideXlab platform.
-
Simplified tape helix Analysis of the planar helix slow wave structure with straight edge connections
IEEE Transactions on Electron Devices, 2018Co-Authors: Ajith Kumar M M, Sheel AdityaAbstract:Tape-helix Analysis for determining the dispersion characteristics as well as the interaction impedance of a planar helix slow-wave structure with straight edge connections (PH-SEC) is presented. The Analysis is Simplified by using the characteristic equation for an infinitely wide planar helix (PH) in free space and incorporating the effect of transverse confinement by straight-edge connections by applying the effective dielectric constant (EDC) method. It is shown that the results calculated from analytical expressions derived in this manner match well the simulation results obtained from CST in the frequency range far from cutoff. The EDC method is known to be inaccurate over the frequency range below cutoff. The Simplified Analysis is also used to determine the dispersion characteristics of a rectangular helix. The results based on the Simplified Analysis are shown to be more accurate than those from a previously reported complex tape-helix Analysis of the rectangular helix.
-
Simplified tape-helix Analysis of planar helix slow-wave structure using effective dielectric constant method
2017 Eighteenth International Vacuum Electronics Conference (IVEC), 2017Co-Authors: M. Ajith M. Kumar, Sheel AdityaAbstract:Tape-helix Analysis is presented for dispersion characteristics of a planar helix slow-wave structure with straight-edge connections. The Analysis is Simplified in a novel way by using the effective dielectric constant method, which avoids the application of boundary conditions for side connections. The results obtained from Analysis show a good match with simulation results. The Simplified Analysis also provides more accurate results than the previously reported results for the rectangular helix based on tape-helix Analysis.
Yunyun Wu - One of the best experts on this subject based on the ideXlab platform.
-
Simplified Analysis of heat and mass transfer model in droplet evaporation process
Applied Thermal Engineering, 2016Co-Authors: Yunyun Wu, Xiaosong Zhang, Xuelai ZhangAbstract:Abstract A Simplified model on single droplet evaporation into a stagnant gas space is established. The mathematical model is based on molecule diffusion on the droplet surface subjected to boundary conditions of constant temperature and conduction heat transferring on the external surface of the spherical droplet. Constant thermal properties are assumed throughout the Analysis for the droplet. Non-linear empirical equations are applied to the ODEs in the numerical solution to expand its range of applicability. The effects of variables, such as surrounding temperature and humidity, and droplet initial radius were investigated. Furthermore, a comparison is made between the present study and the numerical or analytical solution given in the literature. The results show that the present model can give better results than other numerical or analytical solutions presented in the literature.
-
Simplified Analysis of heat and mass transfer model in droplet evaporation process
Applied Thermal Engineering, 2016Co-Authors: Yunyun Wu, Xiaosong Zhang, Xuelai ZhangAbstract:Abstract A Simplified model on single droplet evaporation into a stagnant gas space is established. The mathematical model is based on molecule diffusion on the droplet surface subjected to boundary conditions of constant temperature and conduction heat transferring on the external surface of the spherical droplet. Constant thermal properties are assumed throughout the Analysis for the droplet. Non-linear empirical equations are applied to the ODEs in the numerical solution to expand its range of applicability. The effects of variables, such as surrounding temperature and humidity, and droplet initial radius were investigated. Furthermore, a comparison is made between the present study and the numerical or analytical solution given in the literature. The results show that the present model can give better results than other numerical or analytical solutions presented in the literature.
