In this study, a modelization of the viscoplastic behaviour of amorphous polymers is proposed, from an approach originally developed for metals behaviour at high temperature, in which state variable constitutive equat...In this study, a modelization of the viscoplastic behaviour of amorphous polymers is proposed, from an approach originally developed for metals behaviour at high temperature, in which state variable constitutive equations have been modified. The model includes the effect of strain rate sensitivity, strain softening and strain hardening. A procedure for the identification of model parameters is developed through the use of experimental data from uniaxial tests extracted from the literature, across a variety of strain rates and below the glass transition temperature ( Tg). The numerical algorithm shows that the predictions of this model well describe the intrinsic softening upon yield threshold and the subsequent progressive orientational hardening typical for amorphous glassy polymers.展开更多
In this paper,we discuss the important role of the thermalization process in the initial distribution of QGP.We find that the negligible heat conduction inside QGP can be expressed as an effective Fourier law and we f...In this paper,we discuss the important role of the thermalization process in the initial distribution of QGP.We find that the negligible heat conduction inside QGP can be expressed as an effective Fourier law and we further analyse qualitatively the results caused by a thermalized initial condition.Based on this arguments,we construct a simple phenomenological model and work with the hydro code,and then we compare our results with the experimental data and the results of the standard initial model.It is found that,as we have argued,a thermalized initial condition suppresses the value of the elliptic flow.展开更多
文摘In this study, a modelization of the viscoplastic behaviour of amorphous polymers is proposed, from an approach originally developed for metals behaviour at high temperature, in which state variable constitutive equations have been modified. The model includes the effect of strain rate sensitivity, strain softening and strain hardening. A procedure for the identification of model parameters is developed through the use of experimental data from uniaxial tests extracted from the literature, across a variety of strain rates and below the glass transition temperature ( Tg). The numerical algorithm shows that the predictions of this model well describe the intrinsic softening upon yield threshold and the subsequent progressive orientational hardening typical for amorphous glassy polymers.
基金supported by the National Natural Science Foundation of China(Grant Nos.11275097,10935001 and 11075075)the Research Fund for the Doctoral Program of Higher Education(Grant No.2012009111002)a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institution
文摘In this paper,we discuss the important role of the thermalization process in the initial distribution of QGP.We find that the negligible heat conduction inside QGP can be expressed as an effective Fourier law and we further analyse qualitatively the results caused by a thermalized initial condition.Based on this arguments,we construct a simple phenomenological model and work with the hydro code,and then we compare our results with the experimental data and the results of the standard initial model.It is found that,as we have argued,a thermalized initial condition suppresses the value of the elliptic flow.
