Abstract
<title>Abstract</title> <p> As disc insulators are widely used, investigating their contamination deposition mechanisms provides scientific guidance for external insulation maintenance. To address current research limitations, this paper divides the particle deposition process into two stages: spatial motion and collision deposition. First, the dynamic forces and trajectories of particles under multi-physics fields are analyzed to obtain pre-collision velocities. Second, a “neck height” <italic>h</italic> parameter is introduced to establish an applicable contact mechanics theory. By comprehensively considering interfacial forces—such as van der Waals adhesion and liquid meniscus support—a normal deposition criterion is defined. Consequently, a complete dynamic deposition model is constructed and simulated via the finite element method. The model is validated against existing experimental results. Findings indicate that the Maugis-Dugdale (MD) contact mechanics theory accurately describes the collision process. Furthermore, contamination deposition increases with wind speed, and larger particle diameters enhance their impact on the surface. Accumulation under a negative DC electric field is also strictly greater than under a positive polarity. Ultimately, this model accurately delineates these dynamic processes, providing a reliable reference for exploring underlying mechanisms. </p>