Papers by Author: Yan Zhong Ju

Abstract: In order to study the conduction performance of the old transmission lines, we carried out a comparative study by testing the heat dissipation of the old and the new overhead conductors (35 kV aluminium cable steel reinforced (ACSR) lines, LGJ70/10). The temperature variation of two distinct types of lines under the identical current flow was investigated in details theoretically and experimentally. Our extensive experiments show that the temperature rise of old lines is higher about 11% than those of new lines with the same current flow of 255 A. By combining the theoretical analysis and experimental observations, it is concluded that the heat radiated power of the old lines is higher about 46% than that of new lines, such high radiated heat power is the main factor affecting the temperature rise of old lines.

Abstract: tower consisted of steel tubes and angel steels has equal advantages which steel tube tower has and not easy to happen some bar breeze vibration,but but the wind vibration response for such transmission tower structure research is less. In the engineering background of a tower consisted of steel tubes and angel steels , set up the finite element model for transmission towers. Using Kaimal spectrum for numerical simulation of wind velocity time history. Of 90 ° Angle of wind direction wind to dynamic response are analyzed, the results show that for the displacement, the maximum of dynamic analysis results 88% larger than the result of the average wind, 53.7% larger than standard wind load static result; For axial force, the maximum of dynamic analysis results 147% larger than average the result of the wind, 108% larger than standard wind load static result. So in view of the transmission tower structure dynamic response analysis should be more precise.

Abstract: Based on experiments of uniaxial compression and flexural experiments, the basic mechanical properties (compressive strength and flexural strength) of reactive powder concrete (RPC) were investigated, the effect of the steel fiber content on mechanical properties of RPC was studied in this work. The resu1ts indicate that the axial compressive strength of RPC had no obvious change with the change of steel fiber content. When the steel fiber content varied from 1.0% to 2.0%, the flexural strength of RPC had no obvious change.When the steel fiber content varied from 2.0% to 5.0%, the flexural strength of RPC increased dramaticlly with the increase of steel fibers content. According to experiment curves, an equation for the compressive stress-strain curve of RPC was deduced with different stee1 fiber content.