Prediction and Model Validation of Corrosion Fatigue Life for BFRP Tendons Under Combined Acidic Environment and Temperature

ABSTRACT The widespread application of fiber‐reinforced polymers (FRP) in engineering is primarily attributed to their superior durability compared to traditional materials. However, under prolonged exposure to harsh service environments, the material inevitably undergoes progressive degradation. The existing durability studies and life prediction models have largely overlooked the synergistic effects of combined environmental actions and mechanical loading conditions. To address this gap, this paper investigates the corrosion fatigue behavior of BFRP tendons under combined cyclic loading, acidic environments (pH = 1.5, 2.5, and 7.0), and temperatures (25°C–50°C). An experimental matrix was designed to couple these variables, enabling the identification of fatigue failure modes and the development of S – N models for each environmental condition. A sequential multifactor life prediction model was developed and validated through a case study. Results reveal that ignoring the combined effect of temperature and acidity leads to an 83.0% overestimation of service life, underscoring the necessity of considering multifactor synergy for realistic durability design.