Coupling of Aging Mechanism and Lifetime Prediction for Silicone Rubber Bonding Structure over MD Simulation

Abstract

Silicone rubber bonding structure is widely used in prominent fields such as aviation matter and aerospace, the performance changes of which are of great concern and the occurrence of joint failure can have serious consequences, so it is crucial to assess the failure mechanism and storage life of bonding structures. In this paper, it is suggested that oxygen and water molecules diffused at the interface further break and cross-link with molecular chains, and the interfacial failure occurs for all three kinds of bonding specimens under the artificial accelerated aging conditions of both thermal and hygrothermal aging. By means of molecular dynamics simulation, the diffusion of molecules in different environments at the interface was investigated, further revealing the aging mechanism of the adhesive structure. The parameters describing bonding structures, interfacial binding energy (E) and diffusion coefficient (D), were calculated to construct the storage life prediction model conforming to the adhesive structure, which supports the use of a silicone rubber adhesive structure.