With the growing demand for durability and reliability in automobile suspension systems, accurate fatigue life prediction of air springs under dynamic cyclic loading has become a key research priority. This study develops a novel fatigue life prediction methodology that builds on the critical plane method and Palmgren–Miner linear damage accumulation theory. The approach establishes a predictive model by statistically correlating the mechanics-derived damage parameter \({\text{DP}}_{\text{eq}}\) (obtained from the stress–strain responses of cord–rubber dumbbell specimens) with experimental fatigue data. Based on this model, the fatigue life characteristics and damage distribution of air springs under different sub-blocks of an equivalent block loading spectrum were systematically analyzed, and the total damage value (D) and fatigue life (L) were calculated. Finite element simulations were conducted to capture multiaxial stress–strain states, enabling accurate identification of critical damage planes and potential failure locations. The model was validated through equivalent block loading tests, yielding a prediction error of 12.12% and demonstrating strong agreement in damage localization. These findings confirm the accuracy of the proposed approach, which reduces reliance on air spring assembly fatigue testing and offers effective insights for optimizing the design and durability of cord-reinforced rubber components under complex service conditions.
