The Critical Role of Interfacial Materials and Boundary Conditions in the Wind-Induced Stress of Post Insulators: A Numerical Investigation

The fracture of outdoor disconnecting switch post insulators under strong wind loads poses a severe threat to power grid safety. Traditional simplified models often neglect the effects of multi-material stiffness mismatch and idealized boundary conditions, leading to inaccurate stress predictions. This study systematically investigates the influence mechanisms of interfacial materials and boundary conditions on the bending stress distribution of post insulators through a refined finite element model that incorporates the porcelain body, cast iron flange, and cement mortar layer. Using COMSOL Multiphysics, mechanical responses under four boundary conditions and varying wind speeds were simulated, with mesh independence rigorously verified (stress variation