Molecular Dynamics Simulation of the Effect of Water Intrusion on the Epoxy Resin/glass Fiber Interface of Composite Insulator Core

Due to moisture intrusion and other reasons, core rod string breakage accidents are common, which brings serious harm to the safety and stability of the power system. The epoxy resin/glass fiber interface is a microscopic interface inside the core rod. The bonding strength of this interface affects the overall mechanical properties of the core rod. It has an important impact on performance. At present, it is difficult to clarify the deterioration mechanism of this interface under moisture intrusion through mechanical testing and physical and chemical morphology analysis. This paper establishes a molecular simulation model of the epoxy resin/glass fiber interface in a water molecule environment to analyze and study the degradation behavior of the interface under water intrusion and the effects of temperature and electric field on the degradation process. The work shows that: when the temperature is low (213K-293K), although increasing the electric field value can cause the water molecules to move directionally, the interface does not change significantly because it has not reached the hydrolysis temperature; when the temperature is higher (373K-613K), the water molecules Molecules easily migrate to the interface through the internal holes of the epoxy resin. Increasing the electric field value can accelerate the migration of water to the interface and the hydrolysis process of the epoxy resin; when the temperature further increases (613K-853K), the thermal motion of water molecules is violent and the epoxy resin Hydrolysis is serious, and increasing the electric field value and temperature value has no significant effect on the interface degradation under moisture intrusion.