Multi-Model Lifetime Prediction of Silicone Rubber Under Coupled Environmental Stressors Based on Accelerated Testing in Simulated Marine Atmospheric Conditions

Abstract

Marine equipment operating in atmospheric marine environments is subjected to multiple interacting stressors, making the durability of silicone-rubber sealing components and their lifetime prediction both critical and difficult to assess. This study investigates the degradation behavior of silicone rubber under representative marine conditions and establishes a multi-model framework for accelerated lifetime prediction. Compression set was used as the primary degradation indicator and failure criterion because it reflects long-term stress relaxation and the functional retention of sealing materials. Accelerated aging tests were carried out under ultraviolet (UV), hygrothermal, salt-spray, and two coupled conditions: UV–thermal–humidity and UV–hygrothermal–salt-spray. Corresponding statistical degradation models, a piecewise power-law model, a drifted Wiener process model, and a saturation-type model were developed based on the observed degradation patterns. The results indicate that different aging conditions produce distinct degradation modes: UV and salt-spray aging show marked fluctuations, whereas hygrothermal aging exhibits a more stable and continuous degradation trend. Coupled environments further modify the degradation pathway, revealing nonlinear interactions among stressors rather than a simple additive response. The proposed multi-model framework demonstrates good adaptability across different degradation mechanisms and provides a practical basis for the lifetime assessment of silicone-rubber components used in marine equipment.