Abstract:In order to study the mechanical properties of the composite insulator mandrel under corrosion conditions,using the self-developed insulator torsional vibration simulator,the fatigue test of composite insulators was carried out under different corrosion conditions.The FXBW4-110/100 insulator was selected as the research object.The macro-morphology and optical-microscope of the surface morphology of specimen fracture was analyzed by three-dimensional profiler and scanning electron microscope.Combined with surface analysis techniques,the relationship between the fracture of insulator core and its swing force,torsion force and tensile force under different corrosion test conditions was studied.The results showed that the corrosive liquid has little influence on the mechanical properties of the composite insulator under the neutral and alkaline corrosion solution conditions.However,when the corrosive liquid is acidic solution,the composite insulator core rod would be obviously corroded.When the resin glass fiber inside the rod is corroded by strong acid,the sample is flat and bright.When the surface cracks in mechanical properties,the crack will gradually expand.And the section of the insulator core rod is prone to fatigue fracture.After the insulator is eroded by acidic salt spray,the acid will infiltrate the surface of the core rod and the sheath.The surface of the mandrel or the interface of the plexiglass will be corroded.When the fatigue fracture appears,the fracture surface changes from bright flat to gray uneven,the crack changes from the river pattern to the shell line like shape changes to the fiber bulk,and the root mean square height and the maximum sag height of the surface topography decrease.The anti-pendulum power of the mandrel is decreased with the increase of corrosion test time.Furthermore,the mechanical properties of the insulator are reduced,which will result in the shorter fracture time,larger fractal dimension of fracture,and more complex fracture surface topography of the core rod.