Mechanical-electro-thermal coupling ageing and fracture failure mechanisim of composite insulator rods
Composite insulators are widely used in transmission lines,but their ageing and fracture problems cannot be ignored.In order to study the cause of fracture of composite insulators and the mechanism of mechanical-electro-thermal ageing,a mechanical-electro-thermal ageing experiment platform was designed to carry out multi-field coupling ageing tests on short rod samples of composite insulators.The results show that the ageing insulator rod sample has fracture phenomenon.During the process of rod fracture,the macroscopic characteristics are the expansion of crack and fracture surface,and there are discharge marks near the high-voltage electrode.The microscopic characteristics are epoxy decomposition,glass fiber microcrack and fracture,and fiber-epoxy interface failure.At the same time,a multi-field fracture failure evaluation model of mechanical-electro-thermal coupling is established based on the unit break rate,and the inverse relationship between the unit break rate and the energy barrier is revealed.Under the given electrical,thermal,and mechanical stress conditions,the model can evaluate the ageing degree of composite insulator rod according to the ratio of fracture area,and can provide a reference for the ageing failure analysis of composite insulator rod under the synergistic action of multiple stresses.
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维普
