新疆地区750 k V特高压线路,局部线路长期受大风影响,其U型环投入不久便出现严重磨损。通过对U型环进行实物摇摆磨损试验及实物破坏载荷试验,得出以下结论:随试验载荷的增加,磨损次数对U型环剩余强度的影响变得更为严重,0.8 t载荷、15...新疆地区750 k V特高压线路,局部线路长期受大风影响,其U型环投入不久便出现严重磨损。通过对U型环进行实物摇摆磨损试验及实物破坏载荷试验,得出以下结论:随试验载荷的增加,磨损次数对U型环剩余强度的影响变得更为严重,0.8 t载荷、15万次磨损下U型环剩余强度已不足实验前的1/2。上U型环平均截面剩余尺寸比下U型环小4.3%。U型环磨损速率大致呈线性。为处于大风地域的输电线路金具的设计、检修和维护提供试验依据。展开更多
The formulae for stresses and angular displacements of U-shaped bellows overall bending in a meridian plane under pure bending moments are presented based on the general solution for slender ring shells proposed by Zh...The formulae for stresses and angular displacements of U-shaped bellows overall bending in a meridian plane under pure bending moments are presented based on the general solution for slender ring shells proposed by Zhu Weiping, et al. and the solution for ring plates. The results evaluated in this paper are compared with those on EJMA (standards of the expansion joint manufacturers association) and of the experiment given by Li Tingxilz, et al.展开更多
This is one of the applications of Part (Ⅰ),in which the angular stiffness, and the corresponding stress distributions of U_shaped bellows were discussed. The bellows was divided into protruding sections, concave sec...This is one of the applications of Part (Ⅰ),in which the angular stiffness, and the corresponding stress distributions of U_shaped bellows were discussed. The bellows was divided into protruding sections, concave sections and ring plates for the calculation that the general solution (Ⅰ) with its reduced form to ring plates were used respectively, but the continuity of the surface stresses and the meridian rotations at each joint of the sections were entirely satisfied. The present results were compared with those of the slender ring shell solution proposed earlier by the authors, the standards of the Expansion Joint Manufacturers Association (EJMA), the experiment and the finite element method. It is shown that the governing equation and the general solution (Ⅰ) are very effective.展开更多
The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results...The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results show that the wind pressure on the windward side of the U-shaped ring is the highest,a negative pressure zone appears on both sides of the U-shaped ring,while a Kármán Vortex Street is created on its leeward side.There are three possible regimes of motion for the sand grains in the wind field.Sand grains with size below 0.125 mm can follow the airflow directly into the contact area of two U-shaped rings.When the sand size is about 0.1 mm,the number of sand grains that are blown into the contact area attains a maximum.Through the simulation of U-shaped rings in the wind-sand field,the dynamics of such processes are explained in detail,thereby providing relevant information for the subsequent protection and design of connecting hardware used for power transmission.展开更多
文摘新疆地区750 k V特高压线路,局部线路长期受大风影响,其U型环投入不久便出现严重磨损。通过对U型环进行实物摇摆磨损试验及实物破坏载荷试验,得出以下结论:随试验载荷的增加,磨损次数对U型环剩余强度的影响变得更为严重,0.8 t载荷、15万次磨损下U型环剩余强度已不足实验前的1/2。上U型环平均截面剩余尺寸比下U型环小4.3%。U型环磨损速率大致呈线性。为处于大风地域的输电线路金具的设计、检修和维护提供试验依据。
文摘The formulae for stresses and angular displacements of U-shaped bellows overall bending in a meridian plane under pure bending moments are presented based on the general solution for slender ring shells proposed by Zhu Weiping, et al. and the solution for ring plates. The results evaluated in this paper are compared with those on EJMA (standards of the expansion joint manufacturers association) and of the experiment given by Li Tingxilz, et al.
文摘This is one of the applications of Part (Ⅰ),in which the angular stiffness, and the corresponding stress distributions of U_shaped bellows were discussed. The bellows was divided into protruding sections, concave sections and ring plates for the calculation that the general solution (Ⅰ) with its reduced form to ring plates were used respectively, but the continuity of the surface stresses and the meridian rotations at each joint of the sections were entirely satisfied. The present results were compared with those of the slender ring shell solution proposed earlier by the authors, the standards of the Expansion Joint Manufacturers Association (EJMA), the experiment and the finite element method. It is shown that the governing equation and the general solution (Ⅰ) are very effective.
基金National Natural Science Foundation of China(51865055)Tianshan Talents Plan of Xinjiang Autonomous Region of China(201720025)。
文摘The interaction of U-shaped rings used for power transmission hardware with a wind-sand field is simulated numerically.A standard kturbulence model is used in synergy with an Eulerian-Lagrangian approach.The results show that the wind pressure on the windward side of the U-shaped ring is the highest,a negative pressure zone appears on both sides of the U-shaped ring,while a Kármán Vortex Street is created on its leeward side.There are three possible regimes of motion for the sand grains in the wind field.Sand grains with size below 0.125 mm can follow the airflow directly into the contact area of two U-shaped rings.When the sand size is about 0.1 mm,the number of sand grains that are blown into the contact area attains a maximum.Through the simulation of U-shaped rings in the wind-sand field,the dynamics of such processes are explained in detail,thereby providing relevant information for the subsequent protection and design of connecting hardware used for power transmission.
