Tension-tension fatigue performances of a pultruded carbon fiber reinforced epoxy plate at elevated temperatures

Fatigue performance of pultruded CFRP plate at elevated temperature is essential for the design process and applications in structure rehabilitation and reinforcement. Here, tension-tension fatigue performances of pultruded CFRP plate at room temperature (RT), 50°C and 83°C (Tg minus 30 °C) were investigated along with static tension properties. The static tensile strength at different temperature (fᵤᵗ), fatigue life, prediction formula, temperature curves, stiffness curves and fatigue failure mechanisms were comprehensively studied in tandem with microstructure. Results reveal, temperature increase and fatigue load lead to resin thermo-elasto-plastic softening and premature failure; the resultant fatigue life is significantly reduced when temperature is close to 83 °C; the fatigue life at RT, 50 °C and 83 °C exceeds 2 × 10ⶠcycles with 95% reliability under stress level of 49.95%fᵤᵗ, 49.03%fᵤᵗ, and 43.24%fᵤᵗ, respectively.