基于ASME应变限制准则的小冲杆试验等效断裂应变

为更清楚地了解阳江35kV服役导线的运行状态,从分析导线断线原因出发,通过对老旧导线的单丝断裂强度、弹性模量、应力应变曲线、拉断力、抗拉强度等综合指标的测试与分析,研究服役导线的力学性能,由试验结果得出：35kV老旧导线钢芯的直径变化对于架空导线的外径变化有直接的影响,老旧导线的铝线直径变化较小,其外径增大1.67％~4.24％;钢单线的拉断应力仍能达到标准中规定值的106%,且伸长率也满足要求;部分铝线的抗拉强度低于95%;绞线拉断力仍能达到95%的计算拉断力。但是相同规格下的老旧导线的抗拉强度比新导线的抗拉强度低2%~18%。结果表明：阳江地区服役三十年以上的老旧导线在力学性能上仍能继续承载。

On the Equivalent Fracture Strain in Small Punch Test based on ASME Strain Limit Criterion

In order to more clearly understand the running status of Yangjiang 35 kV in service wire, from the analysis of reasons for wire disconnection, mechanical properties of in service wire were analyzed based on measurement of its comprehensive index, such as monofilament breaking strength, modulus of elasticity, stress-strain curve, tensile failure force, tensile strength etc. Results show that firstly, the diameter variation of old steel core wire has direct effect on the outside diameter of overhead wires, the outside diameter of old wire increases 1.67% ~ 4.24%; secondly, the tensile failure stress of single wire reaches 106% of specified value in standard, and the elongation percentage also meets requirements. Most aluminium wires still meet the tensile strength requirements except small part of wires are lower than 95%. The tensile failure force of stranded wire still reaches 95% of the calculated value. The tensile strength of old wire is lower than that of new wire by 2%~18%. Results indicate that the old wires can still continue to carry load.