Storage Reliability Modeling of Polyurethane Seals for Electrical Connectors

On the issue of reliability assessment of electrical connectors for missiles in long-term storage environments. Failure analysis of polyurethane adhesive seals for electrical connectors in a storage environment. The polyurethane adhesive seal failure is identified as a seal leak caused by a combination of cohesive failure and boundary failure. The degradation mechanism of polyurethane adhesive in storage environment is the oxidation and hydrolysis of large molecular groups inside the polyurethane adhesive caused by temperature and humidity. Based on Newton's law of viscosity and Roth seal theory, a mathematical expression for gas leakage combining cohesive failure and boundary damage is established. Based on molecular dynamics and the law of mass action, the mathematical relationship between the performance degradation rate of polyurethane sealant and temperature and humidity is established. To establish the performance degradation trajectory of polyurethane adhesive seals for electrical connectors containing temperature and humidity, using the gas leakage rate of the adhesive seals as the performance index. Combined with the central limit theorem, a statistical model for the storage reliability of polyurethane adhesive seals is developed, it can provide a theoretical basis for evaluating the sealing reliability of polyurethane adhesive for electrical connectors in storage environments. © 2024 Chinese Mechanical Engineering Society. All rights reserved.