Research on the influence of thermal shock on the mechanical strength of basin-type insulator based on multidimensional data

Basin-type insulators are major insulating components in GIS (Gas Insulated Switchgear), and have significant influence on the performance and reliability of the equipment. The basin-type insulators are mainly manufactured through epoxy resin vacuum-casting process. As “ceramic-like” materials, epoxy resin would bring internal stress during the curing process. The failure mechanism of this kind of material is the defect theory, which determined by the characteristic of epoxy resin, especially for the components with more complex structure. The current standards and technical specifications mainly evaluate the influence of slowly changed ambient temperature on the mechanical strength of basin-type insulators through temperature cycling test. The influence of thermal shock on mechanical strength of basin-type insulators is still not clear. In this paper, thermal shock test which could amplify (or accelerate) the microscopic damage of epoxy resin was proposed and the effect of rapid changed temperature on the mechanical strength of basin-type insulator was analyzed by simulation and experiment results on basin-type insulators with typical structure. The results showed that the hydraulic fracture strength of the basin-type insulators with thermal shock test was about 33% lower than that of basin-type insulators without thermal shock test. Therefore, the thermal shock test has a great influence on the mechanical properties of basin-type insulators and this may provide an effective method for quality control of basin-type insulator.