The computation of stable or unstable manifold of two-dimensional is developed, which is an efficient method in studying stable structure analysis of system character geometrically. The Lorentz stable manifold is comp...The computation of stable or unstable manifold of two-dimensional is developed, which is an efficient method in studying stable structure analysis of system character geometrically. The Lorentz stable manifold is computed by the fixed arclength method and the hyperbolic equilibrium is a saddle. The two-dimensional stable structure of Lorentz manifold is significant in people’s usual view. We also introduce the V-function to compute the V-manifold correspondingly. The defined V-function is smooth in the unstable direction of the manifold. Especially, the routh to period-doubling attractor on manifold surface is discussed too.展开更多
The experimental study on the volume fraction of retained austenite for QP980CR steel under high-strain-rate tension is briefly described. An interrupted tensile split Hopkinson bar （TSHB） is developed to control th...The experimental study on the volume fraction of retained austenite for QP980CR steel under high-strain-rate tension is briefly described. An interrupted tensile split Hopkinson bar （TSHB） is developed to control the elongation of specimens. The QP980CR steel sam- ples recovered from the interrupted TSt-IB tests are investigated using synchrotron X-ray diffraction （XRD） to analyze the effects of strain and strain rate on the martensitic trans- formation of retained austenite. A constitutive model of QP980CR steel coupling with the transformation-induced plasticity （TRIP） effect is presented based on Delannay＇s mean-field modeling. The stress-strain curves of quasi-static and dynamic tensile tests for QP980CR steel are compared with the results predicted by the presented constitutive model. The dif- fuse necking of QP980CR steel sheet specimens in TSHB tests is analyzed using Batra and Vv＇ei＇s instability criterion and the presented constitutive model. The effects of strain rate and temperature on the dynamic tensile fracture strain of QP980CR steel are also given.展开更多
文摘The computation of stable or unstable manifold of two-dimensional is developed, which is an efficient method in studying stable structure analysis of system character geometrically. The Lorentz stable manifold is computed by the fixed arclength method and the hyperbolic equilibrium is a saddle. The two-dimensional stable structure of Lorentz manifold is significant in people’s usual view. We also introduce the V-function to compute the V-manifold correspondingly. The defined V-function is smooth in the unstable direction of the manifold. Especially, the routh to period-doubling attractor on manifold surface is discussed too.
基金supported by the National Natural Science Foundation of China(nos.11372149 and 11572164)the Zhejiang Provincial Key Science and Technology Innovation Team(2013TD21)programK.C.Wong Magna Fund in Ningbo University
文摘The experimental study on the volume fraction of retained austenite for QP980CR steel under high-strain-rate tension is briefly described. An interrupted tensile split Hopkinson bar （TSHB） is developed to control the elongation of specimens. The QP980CR steel sam- ples recovered from the interrupted TSt-IB tests are investigated using synchrotron X-ray diffraction （XRD） to analyze the effects of strain and strain rate on the martensitic trans- formation of retained austenite. A constitutive model of QP980CR steel coupling with the transformation-induced plasticity （TRIP） effect is presented based on Delannay＇s mean-field modeling. The stress-strain curves of quasi-static and dynamic tensile tests for QP980CR steel are compared with the results predicted by the presented constitutive model. The dif- fuse necking of QP980CR steel sheet specimens in TSHB tests is analyzed using Batra and Vv＇ei＇s instability criterion and the presented constitutive model. The effects of strain rate and temperature on the dynamic tensile fracture strain of QP980CR steel are also given.
