Analysis of mechanical properties of insulators pecked by birds

Silicone rubber insulators, widely used on transmission lines, are often pecked by birds, which affects their insulation performance. For the power system to run safely, it is necessary to research on mechanical properties of insulators pecked by birds. To access the ability of insulators against birds' pecks, the impact model based on theories of impact dynamics is build. According to the different velocities of birds' pecks, the damages on insulators surfaces are divided into three stages: elastic deformation stage, plastic deformation stage and flow deformation stage. This paper derives the functions of the impact depths on different stages. The paper finds that the insulators materials' elastic modulus, poisson's ratio, static compressive yield stress and density can be used to access the ability of insulators against birds' pecks. An impact tester simulating birds' pecks was utilized to conduct impact experiments and the conclusion is drawn. After observing the damages of silicone rubbers with the increase of the impact height and fitting the impact depth curve, the standard deviation is 0.1487 and the fitting parameter is very close to parameter in theory, which means that the impact model can depict the relationships of silicone rubbers between the impact velocities and the impact depths well.