Papers by Author: Ran Li

Abstract: Dynamic response of conductor breakage is analyzed on guyed oxytropis transmission tower-line system of 500KV 5291 JinJiang-Zhenjiang lines. Considering unbalanced tension, finite element method is presented. Result of the transient analysis shows that the vibration of tower-line system happens after conductor breakage. With the damping affect，the system vibration becomes gentle. For the tension of lines, the peak value of dynamic tension of conductor can be times of the initial tension. It is shown that the proposed method is of efficiency and practicality.

Abstract: The changes of phase composition and structure evolvement of Fe and Si powders with the ratio of 6.5wt%Si to 93.5wt%Fe were mainly studied. It is found that, the local graded structure, Fe-Fe(Si)-Fe3Si-(FeSi)-Si, forms due to the obvious diffusion and the alloying reaction between Fe and Si powders when sintering at 900-975oC. The graded structure, in which the high silicon phase based on Fe-Si alloys is packed by the low silicon solution based on Fe, exhibits a graded concentration of Si distribution. And most of the Fe-containing phase remains a state of lower Si content, less than that of 3wt%Si-Fe alloy, thus provides the good deformation behavior of rolling and cutting for the compacts. Therefore, it is feasible for the high silicon iron sheets to be produced by the powder metallurgy method.