架空输电线紧线器的可靠性设计

The Reliability Design of Mounting Strain Clamps

本文对大负荷容量架空输电线紧线器设计中的可靠性问题作了深入讨论.对紧线器的结构与受力状态作了计算分析,并对所用铝合金材料进行了低循环疲劳、断裂及裂纹扩展速率等一系列力学性质的试验研究.采用有限元法和应变电测法,确定了紧线器钳体的应变幅值及高应变区域.对于这些区域按局部应力应变法进行了寿命估算,在此基础上改进了设计,将最高应变幅控制在许用应变幅以内,考察了钳体的损伤容限,使紧线器安全可靠性能得到充分保证,其重量也大幅度减轻.

In this paper,the reliability problem in designing the mounting strain clamps with large load capacity for overhead power transmission lines are investigated.The structure and the load of the clamp are analysed in detail.A series of mechanical experiments of a new aluminium alloy on low cycle fatigue,fracture and crack propagation rate are performed and analysed. Based on the finite element method and the experimental stress analysis,the strain levels of the high strain regions in the clamp body are determined. The safe life of a clamp is estimated according to the local strain approach (LSA)and,consequently,the design of the clamp is improved to make the strain level within the allowed value.The reliability of the clamp body is assured by considering the damage capacity of the clamp structure,and the weight of the clamp is reduced by optimization.